Chevy Suburban/Tahoe Rough Idle and Stalling

navalavi8ornavalavi8or Member Posts: 5
edited July 2015 in Chevrolet
I have a 2001 Chevy Suburban 2500, 2WD w/ 6.0L engine. We purchased it from a Chevy dealership back in 2002. It was a GM buy-back, for the same reasons it's now having. NO DTC's, NO CEL.

Having a problem with stalling. It usually happens after backing out of parking areas when vehical returns to idle while shifting from reverse to drive. It then become difficult to restart. Also during this issue if vehical doesn't stall it starts exibiting erratic idle. The vehical also seems to idle low 550rpm down to 400 and lower on occasion.

I have attempted to locate the idle air valve but it doesn't seem to have one in the location in the manual (on throttle body by altinator). I can only find what I believe is the Throttle position sensor in that location.

Vehical doesn't do this all the time but nore times than not and seems to be more often during cool/cold weather.

Any help or idea would be gratly appreciated.


See also: GM Extending Warranty On Some Vehicles For Rough V-8 Idle


  • docdandocdan Member Posts: 1
    I have a "Late" 2001 Suburban LT 1500 2WD that stalls when you are slowly moving the vehicle. It most commonly occurs when pulling into a parking lot at idle speed. The vehicle runs great at speed and if you hold your foot lightly on the accelerator it will not die. It is simply that the Idle speed is too low. From what I had read I decided to replace the fuel pump module because it was whining but never quit pumping fuel. I ordered the pump to find that the 2001 module had different plugs than my vehicle had. It took many calls but I found a dealer that researched the problem to find a harness designed to rewire the module to fit my application. The pump did not fix the problem. The next step was to replace the Idle Air Control Valve. I ordered the part and when it came in I went to install it to find that the throttle body on my suburban did not have an IAC Valve on it (I have Pics). I climbed under the dash and put an adhesive spacer under the stop for the pedal and the problem is fixed for now. What is going with these vehicles? HELP!
  • navalavi8ornavalavi8or Member Posts: 5
    After alot of research and calling the chevy dealership that did all the work prior to and after the GM buy back we figured out the problem.

    The Chevy 6.0L w/ electronic throttle (no cable) does not have a idle air control motor (valve). The electronic throttle motor and pcm control the idle. On models that have no idle air control motor there is a small machined opening on on the throttle body that prevents the throttle plate from completly closing. Ater what seems to be a realativly short period of time the back side of the throttle plate and intake will have a large amount of carbon and oil from the EGR and crank vent systems. I removed and cleand the throttle body and what I could of the intake where the TB mounts and it solved all my idle issues.

    BTW I will have to give the Chevy parts manager a plug because he reviewed the work orders (from 2003) and found a mistake on the paper work. The mistake was fuel injectors where replaced which actually all that was done was that the throttle body was cleaned. Then he suggested what I did to remedy the problem. I would have changed uneeded parts with out his help.
  • mark2241mark2241 Member Posts: 1
    i have a 93 suburban with the 7.4 ltr has a miss
    you can feel in gear stopped.i did a full tune up and changed the cat.i also replaced the fuel injectors.i think it might be a bad plug wire but at this point i give up,please help
  • bessbrookebessbrooke Member Posts: 1
    My 1999 454 7.4 liter suburban LT turns over several times when cold before spluttering into life ( it then nees a bit of gas) and Idles roughly. i think it may have a slight missfire. is this a common problem. I have replaced the oxy sensors, fuel pump and plugs n leads but it is still rough and vibrates like a bus. no problems restarting from hot though. ANY IDEAS?
  • plaserplaser Member Posts: 1
    I've had this 1989 GMC Suburban for a couple of years. The engine was relplaced right after we bought the vehicle.The only parts that were not replaced by new parts were the distibuter,ignition modules or anything else on the throttle body. If I am not in gear I can lightly press on the accellerator(ACC) and it won't try to stall but if I put it in gear and try to do the same, like if I'm backing out of a stall or trying scootch foward a little it will try to die out. I have to throttle the accellerator peddle a little to keep it from dying. It started about a year ago and really hasn't gotten worse. Also if I was driving for like 40 minutes or so and I came to a stop on the freeway or something it would try to die out again and I would again throttle the ACC. After I did a really good tune up the stalling on the freeway deal went away but I'm still having issues. The truck doesn't give me any other issues, runs great otherwise and purrs like a kitten when idling. A couple mechanics couldn't find any codes and both said the timing was correct. Like I said it only does it when in gear. Any help would be greatly appreciated. At the very least a suggestion on where to start to replace something.I am also noticing when I try to start the truck it takes a little longer than it used to,it needs more turn over time then it starts up. Before I could just hit the ignition and it would fire right up, kinda like I lose fuel pressure in the line.
  • gmlorrainegmlorraine Member Posts: 1
    I have a 2001 Chevy Suburban. It sounds like the same problems I was having. I replaced my intake manifold gasket it had cracks. Have it checked out for vacuum leaks. They can smoke the engine for leaks. The gasket is made of rubber. So when it is cold it contracts to normal. Which creates a vacuum leak. When the truck is warmed or hot the gasket expands. Have it checked for vacuum leaks in the morning after the truck has sat. don't test for vacuum leaks when car is hot. hope this works
  • fryall4fryall4 Member Posts: 1
    I have a 93 Chevy Suburban 4X4. 5.7, AT, A/C, all power. Problem is after warm up and stopping at a light the truck will stall. It starts up quickly and runs perfectly off idle. I have replaced the fuel filter, Idle air control valve, plugs, cap nd rotor with no solution. I have been researching and think the problem may be the Torque Converter Clutch lock up solenoid (TCC). There is a way to test this, but I don't know how. I don't have the $ to take it in, I just dropped $1400 on a blown up rear end. Does anyone else know how to test this solenoid on a 4L60E? Or maybe what the problem might be? Fry-
  • burbloverburblover Member Posts: 1
    I have an '02 Surburban that has a rough idle on cold start. Typically, the temps have to be 40 degrees or below for this to occur. It never happens during the warm spring, summer and fall months. I replaced the fuel filter last fall and was told at that time by the local dealer that my burb has a flex-fuel motor and that this was a bit rare for this year model. At times, the check engine light will activate during the rough idle. Sometimes the light flashes and goes off after a half hour or so, and sometimes it will come on and stay on for as much as a day or two. The burb always runs fine after warming up, even if the light stays on. I have attempted to have the code pulled when the check engine light comes on, but the last two times, nothing shows up. Anyone have advice for me? The truck runs great 85% of the time.
  • ksmockksmock Member Posts: 2
    I have a 1997 sub with a 7.4 liter and the check engine light is on. Every time I start the engine it shuts off unless I rev the engine. If I try to just rev the engine once after starting the engine will continue to miss or shut i off until it gets cleared out. Somtimes the engine will even sputter right after I start driving. I have hooked up a scanner and it gave me 3 differnt possibilties mass air flow, pcv valve, or leaking fuel injectors. I have replaced the PCV vale. But before I go any farther and buy parts I dont need does anyone have an idea what is wrong?
    After the engine clears out the thing runs great but my gas millage is horrible.
  • angielacyangielacy Member Posts: 1
    I have a 99 tahoe it is stalling when i come to a stop or at an idle, and sometimes when i am driving down the road it will not take any gas for a minute then it will go. The main confusion is it only does this when the temp outside is 85 degrees or higher. When it is cooler out it runs like a brand new truck!!! I have replaced the IAC valve, plugs and wires, cap and rotor button. none of these has made a bit of difference. ANY HELP would be greatly appreciated.
  • bc13bc13 Member Posts: 32
    I was having the same problem with my 2000 suburban. Had a tune-up but that did not correct the problem (needed the tune-up anyway, so no loss there). The solution (atleast for now) was reflashing (??? or reprograming?) the ECM (computer). It seems to have corrected the problem and its running pretty well now.
  • stash1stash1 Member Posts: 2
    My 2002 Chev Suburban has a slight tremor or vibration when it is idle or at a red light. I have replaced the plugs, and added gas treatment, but it still vibrates. It noticed it right after a fillup with 87 octane gas, and wonder if it is a gasoline issue.It has 52k miles on it, and otherwise runs great.
  • chevy95chevy95 Member Posts: 1
    I have a 95 Tahoe that we recently purchased with a 350 5.7 L, it has a rough idle when cold and worsens when warms up. I've changed all the plugs,wires, rotor and distributor cap and a new fuel filter and still nothing. Can anyone give advise on what this could be.
  • amarayamaray Member Posts: 1
    I am having the same exact issues with my '03 Suburban. I literally just cut and pasted your symptoms here to save me time in telling you exactly what mine is doing. Typically, the temps have to be 40 degrees or below for this to occur. It never happens during the warm spring, summer and fall months. I replaced the fuel filter last fall and was told at that time by the local dealer that my burb has a flex-fuel motor and that this was a bit rare for this year model. At times, the check engine light will activate during the rough idle. Sometimes the light flashes and goes off after a half hour or so, and sometimes it will come on and stay on for as much as a day or two. The burb always runs fine after warming up, even if the light stays on.

    However, I just dumped $1600 in it over a 4 week time. I replaced fuel filter, fuel pump, had my fuel injectors cleaned, 2 O2 sensors, MAF Sensor and today a throttle body. The light came on 45 minutes after leaving the service dept.

    Anyone had any advice for the first one that might work with this one?
  • fedexbobfedexbob Member Posts: 1
    The battery in my 03 Tahoe went bad so I bought a replacement and installed. Now it wont idle correctly,wants to die and frequently does. Car was working great before dead battery.What am I missing? Help!!! Bob
  • kiawahkiawah Member Posts: 3,666
    Not a whole lot to go on here, but I would go have the battery and alternator checked under load testing. Since you've had a power problem, I'd start with ensuring that the power was good. Most autoparts chains will do a free load test to make sure your alternator is putting out the power that is needed, and your battery is good.

    In your case, I would also make sure your battery connectors are clean of corrosion, fit snugly on the battery, and the cable isn't deteriorated at the connectors.
  • lakeman51lakeman51 Member Posts: 3
    I am having EXACT same problem and have spent a lot of money to no avail. Have you ever figured out the problem?
  • navalavi8ornavalavi8or Member Posts: 5
    I highly recommend any one who is having idle stalling problems to remove and clean your Throttle Body. GM in my mind made a serious design flaw when engineering there system by eliminating a Idle Air Control Valve. Instead they machined a small opening (on one half the dia. of the TB bore) in the throttle body the prevented the throttle plate from closing completly. Well as soon as carbon builds up on the back side of the throttle body from the EGR then the machined opening starts to get restricted. Once the electronic throttle servo/motor can't compensate then you start having stalling that will only get worse until the Throttle Body is removed and cleaned as well as the inlet to the intake manifold. This info was passed on to me by a GM dealer Parts and Service manager who owned one as well. I followed his advice and have had NO issues for over a year. Keep in mind that this will be requied service evrey couple of years as needed to prevent or eliminate the issue as it will return due to the design.
  • kiawahkiawah Member Posts: 3,666
    Being very mechanically inclined and doing all the work on my vehicles (but never had to do that particular task before), how difficult is it and/or how long does it take/or what are the major steps involved?

    I assume they make some throttle body spray cleaner, like the old gumout of carb days.....
  • burbbuddyburbbuddy Member Posts: 1
    I own a 85 El cameo with a 350 Chevy in it many Tahoe's have a like engine
    if yours dose. heres how I cured mine I first tried to replace the solenoid. That
    made the car run smother but it would still stall a red lights some times. so I
    called my friend who works on older cheviots.He said replace the starter and that
    fixed everything I had this problem for a year and no mechanic would touch it
    for under 300.00 estimate . That was a month ago and it runs better than new now.
  • lakeman51lakeman51 Member Posts: 3
    Sorry, but I fail to see how a "starter" can effect the way an engine runs. After the engine starts, the "starter" has no further function. The starter gear slides back into its shell and waits for the next engine crank. Do some starters perform an additional function that I am not aware of? Thanks.
  • woodyjwoodyj Member Posts: 6
    My wife and I purchased a 2003 Chevy Suburban. At first, we had no problems until we had the vehicle for a few months. We ran the ODB II diagnostics and found several cylinders misfiring, and injector circut malfunctioning. We then took it in to dealer to have it further diagnosed and fixed. They did their thing and replaced one injector wire at first, but that did not fixed the issue. Problem reoccurred after we brought the vehicle home. So we took the Suburban in again and they said they had to replace 3 more injector wires. They did that, and everything was fine until another week passed. Same problem again. I got tired of the run around and didn't have the patience with the dealer, or the money we were throwing away. I did simple check of sparkplug, sparkplug wires, fuel injector wires, and to my surprise it was the main ignition coil connector wires. I ended up splicing up the wires together. I did more checks inside the wire jacket that leads back to the main computer in the engine. Found more wires that were worn down to the copper. Seems like either prior owner or dealer tried to fix the problem and couldn't find the main issue.
    So now, my Suburban runs fine.
  • pear69pear69 Member Posts: 20
    Don't know if you solved this problem, but YES 87 octane gas will cause this problem. Octane is an additive that is put into gasoline to reduce the spontanious combustion that happens when gasoline is compressed inside of the combustion chamber. The lower the octane the higher the chance of spontanious combustion. This is bad because if gasoline combusts (fires) before the spark plug ignites the piston will be on the way up in the cylinder. This is what is known as a "ping" or "detonation". A "ping" will eventualy destroy a motor.
  • elorenzo39elorenzo39 Member Posts: 20
    I have a 99 Suburban with a 5.7. I had a leak on my intake gasket and got that replaced. After a week, engine runs rough and showing P0300. Replaced cap/rotors, plug, wires, MAP sensor, Cam Sensor, and Crankshaft sensor. Then I replaced the ecm. Still doing the same thing. Mechanic advised me that it can be the head gasket that will run be about $1200 to $1500. I don't think thats the problem. I did not let them fix the head gasket. After I replaced all the things that I replaced, now its showing p0304 cylinder misfire on 4. Please help if anyone solved the problem. Can it be my EGR valve, fuel injector? I checked the plug on cylinder 4 and it is firing fine.


  • kiawahkiawah Member Posts: 3,666
    You could have a bad head gasket around cylinder#4, right?

    Have any compression tests done??
  • pear69pear69 Member Posts: 20
    It is very important that A/C delco spark plugs, and spark plug wires are used on these engines.  A p0300 is a general misfire and a p0304 is cylinder 4 misfiring. They both may or may not be related. Your engine has a problem that many people overlook, the distributer gear wears out--especialy after it is removed and put back in--as it was when you had the intake gaskets done. If the distributer gear wears too much it will misfire the engine. Also, the timing on your engine must be set with a computer scan tool, NOT a timing light--like in the old days. When the distributer was removed on your engine, it is almost impossible to put back in exactly perfect. This is a commonly overlooked problem also. A dealer is the only one who can properly time your engine. When the intake is removed from the engine, the injector electrical connector must be unplugged. This plug is very sensitive to damage. It is easy to bend the little pin that plugs into the injector. This could be the cause of cylinder 4 missing.Also make sure that all the ground wires are put back on the engine. The ECM fires the injectors by controlling the ground (not the hot or power wire). If a ground is off it could overload the ground system by putting strain on other grounds to pick up the slack. Grounds work just like power wires when it comes to overloading.  This also could be an intake leak. Start the engine and let it run for a while. Now, get a spray can of electrical cleaner ( CRC ) or brake cleaner and spray it around the upper and lower intake while the engine is running. If the engine boggs down or starts to run bad-and -- then clears up when you stop spraying---you have an intake leak. If this is the case the intake gasket was changed wrong...  The best way to determine if the head gasket is bad is to do a compression and leak down test on all cylinders.    If the plug looks fine then it is probably NOT the head gasket---do a compression test to be sure though....
    Your problem sounds like a leaking intake somewhere or most likely electrical.
  • elorenzo39elorenzo39 Member Posts: 20
    I Thank you all for helping me out. It really helped me alot. I think I got it figured out. The engine has no Vacuum leak. The problem is my #4 fuel injector. I pulled the spark plug that I have installed 2 weeks ago and it looks like the injector is bad. I will be replacing my fuel injector assembly this weekend and I will let you all know the outcome. Cross my finger that the problem is solve. I finally had another mechanic take a look at it last night. He checked the vacuum leak, compression and he came up with a bad injector on cylinder number 4.

    Keep you all posted after this weekend.

    Thank you again.
  • pear69pear69 Member Posts: 20
    If you are changing the entire assembly I suggest installing the upgraded injector assembly. Your stock injector assembly is called a cpfi system--the upgrade is called mpfi. The only difference is that the injector itself is moved from the center of the assembly (stock location) to the port of the intake runner (upgraded location). The reason this is better is that it elliminates the (problem proan) poppet. If the 4 injector is the problem, then it is the poppet sticking --causing a "burp" in the fuel flow. I bet the 4 spark plug is all covered with black soot---carbon--isn't it?
  • elorenzo39elorenzo39 Member Posts: 20
    Thanks for the information. I heard about the upgrade version and that is what I will be looking for tomorrow and I get the new injector assembly. I really appreciate all your help. I will keep you all posted by this weekend if I solve the mystery.

    You are very right. The plugs are only about 2 1/2 weeks old and I have pulled number 2 and 4 plug to compare and you are right on. The number 4 plug was black and the number 2 was perfect. I have also pulled the plug next to 4 and it was fine looking too.

    Anyway, I will keep you all posted and thank you so much.

  • pear69pear69 Member Posts: 20
    Go on Ebay type in sefi update and you will see the updated version of your injector assembly in DR. INJECTORS Ebay store...
  • elorenzo39elorenzo39 Member Posts: 20
    I thank you again. I will check it out right now. Thanks and will keep you all posted.
  • elorenzo39elorenzo39 Member Posts: 20
    I checked out ebay for the sefi update and that is exactly what AutoZone is giving me. They ordered it and arriving tomorrow for me to pick it up. It's about the same price.

  • elorenzo39elorenzo39 Member Posts: 20
    Hello there! I have changed out the fuel injector and unfortunately it did not make any difference. It is still running the same. If I run the car with the MAF Sensor and when the car hits 40MPH that SES light blinks. When I run the car w/out the MAF sensor the SES will not blink and run better but you can still feel the miss-fire but not as much. The only time you will feel it is when you come to a stop and on an idle. Can an O2 sensor create a misfire? I have been reading a lot of forum with the same problems, has anyone fixed this issue? I am leading to the O2 or the MAF sensor. If I can't fix it, I have no choice to bring it to the dealer.
  • elorenzo39elorenzo39 Member Posts: 20
    Hello Pearl69. I still need you wisdom. Can you help?

    Hello there! I have changed out the fuel injector and unfortunately it did not make any difference. It is still running the same. If I run the car with the MAF Sensor and when the car hits 40MPH that SES light blinks. When I run the car w/out the MAF sensor the SES will not blink and run better but you can still feel the miss-fire but not as much. The only time you will feel it is when you come to a stop and on an idle. Can an O2 sensor create a misfire?


  • pear69pear69 Member Posts: 20
    I'll help, but you must start from the beginning. First- before the intake gaskets were changed did the engine have this problem? If the ses light is on then there is a trouble code stored in the computer, what is the code? If you do not have a scanner Autozone-or a place like that- will scan the computer for free. If the light is not on, then wait until it is on and then take it to get scanned. The code is very important. When you changed the spark plugs and wires what brand of wires and plugs did you use? Did you install the updated version of the injector assembly?

    I will help all I can, but answer the four questions I just asked. Please do not change anything on the engine. You must start from the beginning and be patient, If not then do not waste my time. I like helping people but when they go off track and change things that do not need changing then all they are doing is wasting money and time. If you did change the entire injector assembly then that is good. Even if it didn't need it, this upgrade should be done anyway..
  • elorenzo39elorenzo39 Member Posts: 20
    The intake manifold started to leak and had a mechanic work on it. No the engine was running fine. A week after the intake was worked on, I noticed that the engine was shaking and seems like it was fouled up going on an incline (hill) Drove the car home and it seems worst and the engine was rough. Went to AutoZone and got it scanned. First code was P0300. The guys at autozone said to replace the plugs, wires, cap and rotor which I did. Started the car up and there was no change. Went autozone again and scanned it. Now it showing P0304. They said it might be the cam sensor, crank shaft sensor, Map sensors. I bought all those and replaced it and still the same. Went back in to Autozone and showing the same code. My friend told me to look at plug number 2 and 4 and compare. 4 was blackish color and the 2 was clean. He said that he think its the fuel injector so I went to autozone to buy the new spide system. Replaced that over the weekend and no luck. I am running low on repair budget. I would to get this solve myself rather than taking it to the dealer. The car seem to run fine when cold but as it gets hotter you can feel more roughness. It also runs fine if the MAF sensor is not connected. If the MAF is connected and you go 40mph the ses light blinks. MAF disconnected, SES does not blink and able to drive more than 40mph.

    Thanks for your help.
  • elorenzo39elorenzo39 Member Posts: 20
    Hello Pear69. I forgot to give you the brand yesterday.

    Spark Plug (Champion) Purchased at Autozone as well.
    Wires (Dura something from Autozone
    Cap and Rotors purchased at Pepboys (BWD brand)
    Map/cam/crank are BWD brand
    Fuel Injectors brand below. Purchased at Autozone.
    Gp-Sorensen / Fuel Injector
    Warranty - 1 YR 800-1513N $307.99

    I changed all these part after the Suburban start running very rough. First code was a P0300. After changing and installing the plugs/wires code became P0304 and after changing the rest of the part that I bought, the code remain on P0304.

    Thank you in advance for your help.


  • pear69pear69 Member Posts: 20
    I am assuming that the lower intake manifold was leaking when you say the mechanic replaced the intake gaskets.(there is an upper and lower intake manifold)
    If the problem was not existing before the lower intake was removed to replace the gasket then lets start there..... In order to change the lower intake gasket the intake must be removed. You must unplug (and tie out of the way) the entire engine wiring harness. The harness has important ground wires that must be disconnected to remove. Follow the engine wire harness and look for ground wires disconnected. One is connected to the coolant port bolt stud (where the upper radiator hose connects to the upper intake)-if this ground is disconnected the injector ground system will overload and cause your problem. If you find all wires connected move to this---
    The distributer must be removed in order to remove the lower intake manifold. Being that you had a P0300 code (a general misfire condition) the distributer gear could be worn out. Removeing the distributer to check this is not hard at all. If you changed the injector assembly then you can remove the distributer to check this.
    First (most importantly) bring the no. 1 cylinder up to Top Dead Center (TDC). To do this disconnect the battery-- take the air plentum off-- remove the spark plugs and wires--locate the timing pointer on the block (looking at the engine from the front it will be just to the right of the front timing chain cover--spraying some brake cleaner on the pointer may help if it is dirty)--turn the engine "by hand" and align the timing mark on the crank balancer up with the pointer (the balancer mark is a engraved line machined into the balancer)--now very very very carefully remove the distributer cap. On the distributer cap base (where the cap screws down too) there are two notches, one has a number 8 engraved on it and one has a number 6 engraved on it (look very close--use a magnifying glass if necessary). The rotor should be pointing to the number 8. Disregard the number 6 (it is for 6 cylinder engines). This is number 1 cylinder firing position, verify this by compairing the distributer cap to the rotor position;it should be pointing to the contact for cylinder one. If not simply rotate the engine "by hand" 1 turn, until the timing mark on the balancer comes around again--360 degrees. Now you are at TDC...The following is the most important step--with a marker (Sharpie works fine) mark the base of the distributer and a point on the block ,or somwhere, to align up with when you put the distributer back in--unplug the electrical connector in the back of the distributer (cam shaft sensor)...take a carefully loosen the distributer hold down bolt (13mm or 1/2 inch wrench) and remove the distributer. There will be oil dripping so be ready with a rag. Look carefully at the distributer gear. It is very common for these gears to to wear out. The replacement gear should be made of iron or hardened steel--these cost around $70. Check the price on a whole new distributer.
    To reinstall the distributer it is the reverse, but make sure the base is aligned with the (Sharpie mark). Sorry you are not done with the distributer reinstall--Now you must take the truck to the dealer to get it properly timed. The ignition timing on your engine MUST BE SET WITH A SCAN TOOL. It is almost impossible to reinstall the distributer back to the exact same spot--especialy if you replace the gear. Unfortuanatly the dealer is usually the only shop that has this type of scan tool.
    The timing may be the problem all along, because I am sure that after the distributer was removed by the mechanic, the engine timing was not set with a scan tool. This is a common oversight. Also if you replaced the crank shaft position sensor--and you are taking the truck to the dealer for a timing setting you mine-as-well have a crank shaft relearn proceedure done while it is there. The reason for this is too long to explain--just tell the dealer you want a the timming set and a crank shaft position sensor relearn proceedure done--it will take about an hour and will set you back around $60 bucks--A tip--before you bring the truck to the dealer make sure the engine is warmed up for at least 1/2 hour.....Also, I would get rid of the champion spark plugs and the duralast wires--why?--A/C Delco platinum plugs (not the rapid fire ones) and A/C Delco wires are the only brands that work on these engines--The ignition system voltage is very high--and for some reason A/C Delco is designed for this, trust me here. I know that A/C Delco plugs and wires are expencive but they are the only brand that works and they will last another 100000 miles..I would bite the bullet and put in new plugs and wires--see what happens...Keep me posted...
  • elorenzo39elorenzo39 Member Posts: 20
    Thanks Pear69. I will work on the Burb again this Friday when I get off work. I will buy me the new set of A/C Delco Plugs and Wires. I will check everything you suggested and bring it to the dealer and have the crank shaft relearned and the timing adjusted. I will keep you posted. Thank you very much.
  • elorenzo39elorenzo39 Member Posts: 20
    Hello Pear69. I live in California. I made an appointment to bring my truck in at the Chevy dealer and told them about my issue. They advised me about a special warranty for the sequential something and it will be check and repair at no charge. I don't know exactly what their saying but I'll bring the truck in.

  • pear69pear69 Member Posts: 20
    Your factory fuel injection system is called a Sequential Port Fuel Injection system (SPFI). That is what the dealer means by sequential. There has been a lot of problems with this system. You said you installed the updated fuel injection version, make sure you tell them this. The updated version is called Multi Port Fuel Injection (MPFI). At the dealer they may want to run an injector cleaner through your updated system, this could cause problems with the updated system you installed. If it were me I would check the distributer first and replace/or/fix it before taking it to the dealer, you have to take it there anyway to get it timed after messing with the distributer and to have a crankshaft sensor relearn proceedure done. Changing the plugs and wires to A/C Delco is a very worthwhile decision. Keep me posted
    P.S. sorry I couldn't reply last night, the site was down.
  • elorenzo39elorenzo39 Member Posts: 20
    Thank you. I bought the spark plugs last night $6 a piece and will install it maybe tonight and the wires.

    Thanks again and have a great weekend.
  • elorenzo39elorenzo39 Member Posts: 20
    Hello Pear69. Brought the Suburban to the Chevy dealer and they are replacing the whole entire Sequential unit even after I told them I bought a new one already. The truck runs great now. They fixed and replaced the injectors at no charge under California Special Warranty on Sequential unit up to 200,000 miles. They also replaced my distributor assembly, but have to pay for that job.

    Thanks for all the help and advises that you have given me.

  • woodyjwoodyj Member Posts: 6
    What causes Engine Reduce Power to show up on my instrument cluster. Everytime this happens, my engine dies down to an idle and loses power. I have to turn off my suburban and restart it after about a minute. I would appreciate some pointers.
  • pear69pear69 Member Posts: 20
    Elorenzo39, You are welcome. I am curious about the condition of your distributer gear. Was is worn out? That's great that you had the dealer change the injectors for free--A/C Delco plugs are expensive but they last for 100,000 miles--I'll help anytime--good luck. Let me know about the distributer gear if you can--thanks.
  • elorenzo39elorenzo39 Member Posts: 20
    Hello Pear69,

    I wish I could tell more about the Distributor Assembly. I did not see it myself. Dealer just called me and asking me for approval to replace it and I approved the work over the phone. They are jam pack with a few Suburbans and Silverado's with the same issues. They actually had my Truck for a few days. Dropped it off Last Friday and did not get it back until Wednesday morning. Service advisor told me that they are working on alot of vehicle that has the same problem as mine.

    Thanks again for all your help.

  • gators27gators27 Member Posts: 1
    Its not pulling any codes and the Dealer isnt sure what it is either the fuel pump pressure is good they changed the filter, and it still stalls out after its bin running for a couple hours like it ran out of fuel they also told me it could be the cadeletic converter but they werent sure it is only a hunch well i wasnt spending over $1000 on a hunch when they werent sure. Can someone help?
  • mkotzurmkotzur Member Posts: 1
    I have a 2001 chevy suburban 1500 2wd and I've replaced the plugs and wire set. Now the vehicle is running rough and the check engine light is on or blinking. I've checked for a possible bad wire and plug and they are fine. When I hold a spark indicator against each of the wires and only one will show a stronger spark. Switching the wires around still give me the same strong indication. I've also switched the plug wire module around with no effect. Could it be the ignition control module and where is it located on the engine compartment?
  • woodyjwoodyj Member Posts: 6
    I would suggest checking on your throttle position sensor. Either it would be bad tps or bad wire connector. Secondly check on the spark plug module wiring harness, and could be due to bad wires.
  • woodyjwoodyj Member Posts: 6
    Double check your spark plug gaps and check your spark plug module harness connection on both sides of the engine. The check engine blinking indicates short/misfiring. If there is short in the harness, you can check it by moving around the wires close to connector one by one while the engine is running. Have your check engine light checked and post the codes. I would have better understanding of what the problem is.
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