GMC Jimmy Fuel System

mwolf9000

The fuel filter is located along the frame rail on the driver's side. You might check the fuel line connections to the fuel filter. Probably a good opportunity to just replace the filter anyway.

kschreiber49

the fuel gauge hasn't worked since we replaced the fuel pump we disconnected the battery replaced the fuse re connected the battery fuel gauge went to full then empty then in the middle and stayed any ideas?? please help.

mwolf9000

No surprise the problem is with the fuel pump replacement (as opposed to being a problem in the dashboard). I'd tell the garage that replaced the fuel pump that the fuel guage isn't working now and see what they suggest.

snowdawg1

Have 01 jimmy fuel pump is kicking off thought pump was bad I replaced it last night still having issues.Will start after battery is disconnected then reconnected but wont restart. Will a low battery cause this?What would?

subrock86

ok, ill start with some backround information, have a 94 gmc jimmy with the vortec engine, have had the car for a while now and never had a problem with it until this point, recently the car quit on my brother while driving, towed to a garage and left the keys in the glovebox for repair, the next day they called me and said it ran fine, and they couldnt get it to not run......, so i picked it up, brought it home brother took it to work drove it home, few hours later i tried to start it and nothing it just turned over, bought a fuel pressure gauge and its running 60 psi turn key engine off, but just cranks and cranks and cranks, today i bought a new coil and installed, the car sat roughly 1 hour inbeetween starting attempts and installation of the new coil engine started i let it run roughly 20 seconds turned it off and tried again and back to the same old problem just turned over, as i installed the coil the only thing that changed was i was moving around the wires that run from the distributor cap to the coil, and or the power source, pulled a spark plug and had no spark, moved around the coil (wasnt bolted down yet) and got a spark but the engine still diddnt turn over i shocked my dad so i stopped trying lol, just wondering if anyone has a clue whats happening with my truck, im figuring its a short somewhere in the ignition, but dont know where to begin to look, i would appreciate any and all advice thanx guys

tech1help

check the 2 wire harness connector on the pump side,on top of fuel tank. you can reach it from directly behind left drive tire. make sure both wire connectors are tight within connector itself. the rubber grommets also need to be snug. it is recommended to change that specific harness pig tail,when changing pump. if you check fuel pressure at rear of engine,using proper pressure guage. fuel pressure has to be minimum 58 psi,while cranking,or it will not start. your pressure regulator may be at fault and not the fuel pump

tech1help

check crank position sensor and wiring. it will not allow engine to start, if it cannot read crank position and will not give (CEL), check engine light

dorado1

have a 97 jimmy v6 two things i see happening.
missing or seems to be, also taking a few turns to crank.
was told that my fuel pressure could be a factor, from the fuel pump to throtle body. need to mention that I had 3 o2 sensors replaced to pass inspection
help

captainkirk56

96 jimmy 4.3 miss (fuel,or electrical) slightly at 2000 rpm...seems to be getting worse, tach does not fluctuate during this miss, vehicle starts fine. but the miss seems to be getting worse, almost like a cross fire (ignition)...????
any ideas ,,hate going to garage and get 1000 bill for a parts replacer???
see where fuel pressure is very sensitive on these gmc's

and still could have same problem.
thanks in advance

captainkirk56

forgot to say....occasional this problem shows up from a dead stop..pulling away..but not consistant...sometimes ok...sometimes not????

nljewell

My Jimmy is hesitating when first taking off, only when engine is cold. And occasionally when at a steady speed, the rpm's will surge up alittle. I have changed plugs and wires, put new fuel filter on, replaced egr valve, added some BG44K, and am waiting on a new cap and rotor in the mail. I am out of ideas of what is wrong. Any suggestions?

nljewell

Well I put on my new cap and rotor and that didn't do squat. I took it in for a diag. test this morning and the "mechanic" said he didn't know since there was no check engine light on, so he couldn't check the codes. My next steps are to change coil, temperature sending unit, and change trans. filter. Please reply if you have any ideas.

tech1help

when was the last time you checked your cat converter?sounds more like you engine may not be exhausting correctly. if you are driving and it feels like the engine feels like it is cutting in and out, especially when first started or sometimes wnhe you hit throttle, or going up hill. I would definetly be looking at the cat converter, or the fuel pressure regulator.

nljewell

Thank you tech1help, I will definitely give it a shot.

nljewell

Cat. converter tested good. Fuel pressure was at 55/58. Mechanic suggested to spray some carb cleaner around plenum when engine is cold, if idle goes up then that seal might be bad. He said when engine gets warmed up that seal will expand and the hesitation would stop, only causing hesitation when engine is cold.

poorjimmy

:confuse: well one day shut it off, went for lunch, then it wouldn't start, poured gas in throttle body, it would run till gas ran out, so I disconnected the inlet to the fuel filter and tried starting, but no fuel came out...
went for some supper called tow truck, while waiting with the inlet line still disconnected, i tried starting and gas started pouring out?, so i connected fuel line to filter and it started no problem drove it home.

Next day started no problem, drove around town, came home shut it off, and wouldn't restart, this time poured gas in throttle body and still wouldn't even start this time, "scratching head"

check all fuses, replaced relay, disconnected fuel line and re tried, no fuel coming out...
Left for a few days, went out tried to start started right up, tried 3 times then would start with or with gas in throttle body, i have ordered a new pump, and have changed fuel filter, just not sure why it all works one day then nothing, what really gets me is it will crank over but seems to be getting no spark and no fuel.

Any help would sure be nice.

thanks

nljewell

I sprayed carb cleaner around plenum and nothing happened. When I was at work this weekend I parked inside, when I went to leave after it sitting for 13 hr. it took right off with no hesitation????

shootert

I and a Son own 4 S10 Blazers an 1 Jimmy. The Jimmy an 2 Blazers have Vortex Engs. in them. The fuel lines inside the air induction intake or what ever have some kind of plastic type fuel lines going to the spider injector an a return line.
These lines keep splitting , an the leaking fuel goes directly onto the tops of the intake valves resulting in flooding.
Please what are these lines made of,so we might purchase it in a bulk roll.
The Dealer gets a $100.00 per line with end fittings. The line itself is approximently eight inches long !
Can you help us ? Ron N Texas

jstew41

Hi. I have a 2001 GMC Jimmy with a 4.3l vortec. It shuts down all the time while driving down the road but usually only happens when its sittin around a Half tank of fuel. Now it just started doing this when I first start it in the mornings its very hard to start but it idles fine, when I hit the gas it starts mising and the RPMS are very erratic. It runs fine with a full tank. Anyone have any ideas. Any help would be greatly appreciated.

340sport

I have a 1996 GMC jimmy and noticed fuel smell and fuel dripping on the ground. Your problem will be corrosion and pinholes in the fuel line likely just in front of the rear tire at the frame rail where it runs. Basically had to take it to my mechanic who replaced a portion of the rusted fuel line. This will resolve your problem.

singe

Hi,

Did you find a solution for this problem? I have the same vehicle with nearly the same problem.

Reply to this message with any info. It will email me automatically. Thanks!

tiffs26

I have a 2000 Jimmy 4.3 vortec v6. while driving at a steady speed, there is a small hesitation or studder. It seems to only happen if there is 3/4 tank or more. It doesn't matter the temp or weather. I don't know where the fuel pressure regulator is. Can someone tell me where it is so it can be checked. Or any suggestions of what else could be wrong. BTW just changed plugs, wires, cap, rotor, fuel filter, air filter. Not idea.

shootert

tiffs26 catylic converters problems normaly cause your vehicle to run slugish with no power. Before costing a lot of money to replace take exhaust pipe loose from manifold and drive around block. It will be loud but if it does not run much better it's not the converter. Bolt it back up and look for a different problem.

bud357

right behind the master cylinder on the drivers side two little black boxes with wire going into it on the fire wall.

bud357

when you step on the gas going down the road it acts like it wants to bog out. like it is getting to much fuel. then when i let off th gas it picks back up speed. what can cause that.

shootert

Sounds like your fuel filter is starting to stop up.That's what mine was when it acted like that.

jpmacky

My 99 Jimmy has power going to the igniton coil through the 2 wire plug but does not have power coming out of it. When you first crank it over you can get one spark out of the ignition coil wire then nothing.Because of that im not geting any spark to my distributor and nothing out of my distributor

tech1help

check your crank position sensor.if it is no good it will not allow ignition coil to give spark.it has three wires and is located at the front bottom right of engine.it has a 10mm hex nut with a bracket mounting it to the engine.you remove it then check it for ohms.it cost around $40 at your local autozone.so that leaves you $60.

jpmacky

I messed with the sensors over the weekend and was able to get it to fire, but only once. Now when you turn it over it will fire one initial spark and then nothing.

tech1help

Did you check for continuity on the crank position sensor?if it as continuity it is ok. if only one side has power going in and nothing coming out; aside from the reference voltage. you can attempt to jump the wire using a paper clip or piggy back wire. just for testing purposes. it is shaytree. but i can not do to much being i am not in front of the vehicle. I have worked on many vortec engines. and the are very sensitive. also may have to look at you ignition module.it is located under distrubutor cap and rotor.it can be gray or black.you will see the wires coming out back and underneath distributor assembly

evco

how do i by pass the crank position sensor permitly on 95 jimmy v6 vortec? I had to replace the motor and the new motor does not have a spot for the crank sensor and I am not getting spark to coil or plugs. I tested all the parts and they are getting current so after reading the messages posted it seams this must to be my problem (I think). If anyone can help please do so. The car is for my wifes that had a stroke and it is the only one she can now drive. Thank You!

kellybell28

Ok, I got my 1994 Jimmy a few months ago and I don't know what the guy did to it, but here is the situation............ The truck would sputter, like it was outta gas, and would slowly die. So we replaced the fuel pump, but found the gas tank had a crack.....haven't fixed that just yet. The new fuel pump and lines didn't help the issue, seemed to make it worse. Then we discovered that if you open the driver's side door when it starts to "die", and the domelight comes on, it kicks back-up and runs fine. Obviously I can't ride around with the door hanging open.........ANY suggestions would be GREATLY APPRECIATED
Thanks Everyone!!

tech1help

check you alternator for proper voltage and amperage..without the proper amperage it is possible your electronic components, to include injectors and ecm may not function properly.

schwor

Hi everyone

A week ago truck wouldnt start. Fuel pump would not run.Changed fuel pump....Ran for about a week or so and then stalled again while driving. Had towed and then started again. stalled again....When I play around with the electrical connectors, it will start....Is it the connectors or something else. Thanks!

tech1help

It is recommended by GM that when replacing the fuel pump you also replace the weather pack connector.GM sells the connector preassembled, You just have to cut and splice. Sometimes the connector pins get worn and become loose. You can tug on the wires and feel if they are loose. I have seen it before where the connector was the problem and not the pump itself. Best of luck

huntertb1

I have a 93 Jimmy with a 4.3 cmfi. during the summer months this has happened for 3 rd year in a row. It will start perfect in the morning. I can drive it all day long until I shut it off. When I try to restart it, it almost starts then it just turns into a dead crank. It is getting great spark at all plugs. But the fuel rail is no longer getting fuel.

I replaced the Temp sensor switch (the one that goes to the computer, not the gauge) I though sure it was telling the engine it was to hot, but that wasn't it.

Thing is it has to REALLY cool down to restart, like over night.

Now, the other 3 seasons I NEVER have a problem, starts 100% of the time. That's the only reason I still have it.

I am thinking oil pressure sending unit, but not sure how to test? Is it possible that when it gets hot it could be failing? If so can I unhook the connector and will it go into limp mode and start?

Any ideas on this are greatly appreciated, I am at my wits end with this.

mijimmy

I have a 95 jimmy last 8 # of vin are S2534269 this is to tell what fuel system CMFI or CSEFI. My problem is gas getting into oil. any help would appreciated.

wendy_lynn

I have a 98 Jimmy 4x4. It ran fine yesterday but went to start it this morning and it will turn over but not start. I don't hear the fuel pump come on. How can I check to see if it's the pump before I buy one? What else can I check?

tech1help

In order to verify if the fuel pump is bad you will need a ful pressure gauge that peaks at 80psi. There is a shrader valve at the top rear of engine. It has a black cap that needs to be removed. after attaching the guage to the valve. Turn the engine to on position. The fuel pressure at that valve needs to be at at least 53 psi. Or the engine will not start up. Also the weather pack connector on top of the fuel pump goes bad quite often. be sure to check and make sure the electrical connector pins are pushed forward and not pushing back in causing no connection to pump. Last but not least you need to verify the spark plugs are firing. Perhaps your coil went bad. or sometimes especially in cold environments the distributor cap and rotor go bad from corrosion or wear and tear.

wendy_lynn

Thank you very much. Wiggled wires to the fuel pump a little and car started right up. I guess I need to drop tank and look at them.

circuitbreaker

I have a 2001 jimmy and my check engine light came on. I checked for codes and came up with a P0449 code(evap emissions control system valve, sol, malfunction. I changed the purge valve on the manifold as well as the gas cap with Gm parts but code still comes back, any ideas? circuit breaker

bosslady3

Don't know if you found an answer but when my husbands 2001 GMC jimmy was doing the exact same thing, and after trying EVERYTHING else, the mechanic had to replace the fuel pump.

tolus

ok hope someone has a answer for this one.

jimmy has a new fuel pump, filter, Engine temp sensor, distributor ( with new Sensor ). have blow the vacume line to fuel tank clear. no vacume leaks. no fuel leaks that i can see.

Jimmy starts great, runs great , till i reach normal running temp ( about 200-210 ) then while trying to maintain speeds ( usually about 65 mph but sometimes even at 35 mph) the engine will " buck " like trying to stall out, and will die eventually. will not restart for hours normally. WILL restart when i pour or " prime " cpmi with gas but will die when fuel is used up.

checked pressure on fuel line.. 55-61 with key on / idle.

mechanic couldnt cause the problem or diagnose it so im at the mercy of you wonderful people.. please enlighten me and get me back on the road :sick:

tolus

ok .. took it to GMC .. they worked on it a day or two and ended up giving it back without the problem fixed ..

they restricted the fuel line just before the test port on the fuel line and ran the engine and the fuel pump would lose pressure over time.. im getting 7.1 volts to the pump ..

there is no fuel leak and this is the second new pump i put in .. i cant find any restrictd lines or broken wires.. i even replaced the fuel line wiring harness

tech1help

pressure regulator will cause the pump to lose pressure, so will an after market pump. also the weather pack connector that gives power and ground to the pump should be inspected to ensure the pins are not pushed back in and are making good contact. if you get a pump from dealer it comes with the plug included. if not it can be ordered separate. That plug is notorious for going bad

bhill44460

my 1996 gmc jimmy keeps shutting off, after replacing the fuel pump, and filter and coil pack it is still doing the same thing.. seems like it does it more around a half tank or less but it will do it witha full tank if i drive it more than 20-25 miles.. when it shuts off, it will start right back up but will again die within a couple mins. if i let it sit fr about an hour i can get another 20-25 miles out of it, besides what i have replaced, i have always done routine maintenace, changing oil and air filter regularly. when its dying if you press the gas it totally stalls but if you don;t press it it will "idle" at between 450 and 500 for approx twenty seconds :confuse. it has the vortec 4.3 with central sequential fuel injection, does anyone have any clue as to what is causing this, as i am slowly running outta money just to keep it on the road.. :confuse:

tech1help

Have you access to a OBD II scan tool? From the sounds of it it can be 1 of 4 things. #1Oil pressure is low.#2 fuel pressure regulator is defective.#3 Camshaft sensor does not have synchronization.#4 which would be the least likely given the info you have provided would be a defective ignition module. It should not be the crank position sensor, because if it were the cps it would not start back up.

jsuper1

I have a 1993 gmc jimmy and on the 17th it started to act up by sputtering when we went anything over 30 MPH. We then changed the fuel filter that did not work. So we changed the fuel pump that did not work. We changed the fuel pump relay and that did not work either. What else could make it do that? We checked the spark plugs they are good. Our jimmy won't even start without ether but once we get it to start it will run till about 30 and spuuters again if we turn it off itndoes not start again.

tech1help

pressure regulator will cause the pump to lose pressure, so will an after market pump. also the weather pack connector that gives power and ground to the pump should be inspected to ensure the pins are not pushed back in and are making good contact. if you get a pump from dealer it comes with the plug included. if not it can be ordered separate. That plug is notorious for going bad

brandyr24

did u ever figure out what is wrong with ur car mine is doing the same thing.