Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Isuzu Owners Maintenance and Repair



  • wlbrown9wlbrown9 Posts: 867
    Here is a link to a EGR section of the FAQ, links to some photos as well.
  • Hi, had a 91 that did same thing check the in the distributor cap there is a electronic modulator try buying a new one. ;)
  • I have a 1990 4 cyl. with 325K on it. I've had a blown head gasket at 125k, a cracked head (not rebuldable)at 225k and I just did a valve job due to extremly low compression on two cyl, at 325k. If you can do the job yourself a rebult head can be had for $325(I think) on ebay. You have to evaluate time, money, vs. a new car $$$'s. If the rest of the car is good to go, I'd go for it. If you dont want to pour 1k to 1400. for someone else to do the job then it's sinara....p/s eventual head problems with this car are INEVITABLE.
  • sbcookesbcooke Posts: 2,297
    Have you tried disconnecting the battery for 10 minutes? Does 4wd still work when engaged? How about 4wd low? Have you tried Autozone for the code? They pull it free.

    When my actuator was bad, it would flash check when it would sense a slip and would send power to the front. Since the actuator was not working, it wouldn't get power there and fail. So I would guess either you 4wd isn't working, or a sensor is bad. I had no luck with dealers and TOD issues. The sensors are easy to replace from what I can see. Perhaps even cleaning one would fix it...again it is finding out which one and how to access it. It would be worth buying a manual, ordering a part from St. Charles Isuzu and replacing it yourself if you can identify the problem.

    There are some sensors on the front axle that can be reached easily. The only problem is knowledge. I replaced my 4wd actuator myself, but it took a lot of research, I almost bought a helms and probably should have.
  • bluedevilsbluedevils Posts: 2,554
    My Dad ended up taking it to the Isuzu dealer. Still need to bug him for the paperwork so I can see what was wrong.
  • I have a 1997 Trooper, V6, automatic, basic model, 135,000 miles. I'm the original owner. When I slow down (like stopping) the engine will not return to idle speed, but stays at anywhere from 2,000 to 3,000 rpm. At first it was intermittent, but now happens the majority of the time I drive. Had it to the local Isuzu dealer and local mechanic but they're clueless. Maintenance is up to sched. Sometimes while it's staying at driving rpm, and you stop and turn off the car for a few minutes it goes back to operating normally. Also, if you start the engine and leave it in neutral, it won't surge up in rpm, but will immediately (after previously faulting) once you put the transmission in gear. Any help here? :confuse:
  • petecalpetecal Posts: 28
    My Trooper just developed a leak in the power steering line. A picture is

    One drop of pink fluid can be seen hanging from the tubing about two inches to the left of the bracket holding the tubing.

    I believe I can patch it by sliding some rubber hose over the area where the leak is.

    Note, I already did this with the transmission fluid lines to the radiator after they rusted out.

    Before I proceed, I have some questions.

    1) Is this the high pressure side? It is difficult to tell by following the routing of the tubes but I think it is the high pressure side. I don't know if I can get rubber hose that can take the pressure. According to the shop manual, the normal operating pressure is around 580 psi.

    2) Why did they route the tubing like this? Everything associated with the power steering system is on the drivers side. That includes the pump, reservoir, and steering box. For some reason they brought the tubing across the front of the vehicle, behind and just below the radiator and then made a "U" turn and took it back. The "U" turn is the black section of tubing in the right of the picture.

    Did they do this for cooling purposes? Did they do it to reduce the pressure by making the flow cover a longer distance? Frankly I'm stumped.

    The answers to these questions might impact how I solve the problem.

    Thanks in advance,

  • Question???
    Can Trooper 4 cylinder head work be done without removing the engine from the vehicle? Generally speaking, How difficult is a 4 cylinder Trooper to work on. I've been working on Small Block Chevys for a long time. I'm considering a change. I'm a 50 year old back yard mechanic.
  • makayemakaye Posts: 81
    Dealer couldn't figure it out?
    What did the dealer and indy mechanic check?
    It would seem that the problem would be relatively straightforward to diagnose with "common" fuel injection diagnostic / flow charts.
    Did you try a "google" search on fuel injection idle problems?
    How about the Edmunds forum for idle problems?
  • petecalpetecal Posts: 28
    #1) The shop manuals always say to fix the first problem (EGR) first then reset the DTCs. That may make all the other errors go away and stay away.

    #2) I wrote up quite a description about how I rebuilt an EGR that was giving DTC P0405. I gave it to the guy that maintains the Isuzu FAQ and he said he would add it. I can't seem to find it there.

    #3) If anybody can cross reference to a GM, that would be great. I was at Napa store a few years ago and saw a kid buying an EGR for his Blazer that looked just like my Trooper EGR. I should have gotten more information from him. I happened to be passing the same place just a few weeks ago and I had some time so I went in and tried to get the guy to work with me to cross reference it. He was less than helpful even though the store was empty.

    I am sure that the GM EGR can be used on a Trooper or at least it can be cannibalize for parts to repair the Trooper EGR. Believe me, I have dug way down into the operation of the EGR.

    Hope this Helps

  • Hi,
    I've just started noticing that on my '99 Trooper, the front wheels engage when there's no reason they should. Although the "4WD" button is pressed in (i.e., the TOD system is turned 'on'), there was no reason the power shouldhave shifted to the front wheels (the system showed a 50/50 power spit between front & back, and I could feel the drive in the front axel). I tried it again on dry pavement several days later, and the same thing happened. I just had a major service done on the vehicle. It has 48K mi. Any ideas why this could be happening?
  • How's it going. The reason for your high idle is the IDLE AIR CONTROL VALVE, or the THROTTLE AIR BYPASS VALVE. It is called several different things, but it basically makes your car idle by controlling the air going past the throttle plate. It is easy to fix, and I can't believe that a mechanic missed it. Most can see it coming from a mile away. Easy money for the mechanic when you take it to a dealership. When the idle is high, usually hitting it will move the plunger enough to cut the air flow down to normal. That's how most find out that's the problem. Hope that helps.
  • The valve is hanging up at the throttle open or gas pedal depressed setting. When you go down the road, it opens up about 3/4 so when you let off the gas quick, it won't stall the engine. Your's is just hanging up. Whether the valve is gummed up, or the motor part of it that moves the plunger is malfunctioning. It is usually located near the throttle plate. Or where the air pipe comes from your air filter box to the intake. Somewhere there. Has a 2 wire connector going to it most of the time. I checked for you and advance auto parts has one for $38, GP SORENSON IDLE AIR CONTROL VALVE Part #77910077. Once you look at it you will know what I am talking about. The pintle that controls air flow and the motor that goes with it.
  • Yes I do think that you need your trans fluid changed...not flushed. I think on a trans like that you should just do the old fashioned trans fluid change by dropping the fluid pan and replacing the filter, and putting the 4-6 new quarts of fluid in the trans. Some people will say but you don't get the fluid out of the converter, who cares. you have 6 out of the 9 quarts you have in there. And when it mixes it you have some pretty new fluid. If you really want to be crazy about the fluid. In about 5 to 10000 miles just drop the pan and change just the fluid-not the filter. That will give you almost new fluid. That what they did before all this flushing crap came out. I think that it is all bull anyway. When you flush the trans you stir up all that crap inside it. Fine metal and friction material then hang your valves up inside your valve body(provides the shifts1-2-3-4-5)and you are stuck in 1st gear because the garbage scored the valve up. Just be clean when you do it, make sure no dirt off of you goes in there either. Clean the pan,
    with a new gasket to go on = a whole lot cheaper than a $100 trans flush. Oh and NNNNNOOOOOOO Additives. Everything you need is in that fluid. Don't let anyone sell you some bullcrap like that. Not needed. One question, do you really think that they put that stuff in it when it was built at the factory? Nope, you could say because of cost efficency, but I say because it's a gimmick. Some aftermarket company trying to make a buck. I hope this helped. Oh, and coolant flushes are rediculous too. I know because I am a mechanic who no longer works at a stealership. I am in private industry now, I like it much better. I had too much of a conscience. All you need to do is drain and refill your radiator. Sometimes the additives help depending on your nitrate level, but if you D&R, you should be just fine. Remember your belts need changing too, and a air and fuel filter is nice sometimes every 15-20K too. Those are about the best bang for you buck things you can do.
  • You are getting an artificial intake leak from your egr valve probably. It is sticking and probably letting exhaust lean out the mixture, which is causing your missing and bucking. I would replace the egr valve. Cheap if you do it yourself. The reason it clears up sometimes is it probably stops sticking, and then all of the sudden it sticks and leans the motor out. Hope it helps.
  • Change the belts, Drain and refill radiator(much cheaper than flushing which is stupid anyaway)Drain and refill transmission fluid in pan(no flushing or additives, just drop the fluid, clean the pan gooooood with brakeleen and new gasket if not reusable) Check Front end balljoints and tie rod ends(shouldn't charge to check, but don't pay over 20 bucks. It takes a wiggle of the wheel to check both) Air and Fuel Filter are both a good idea at least every 20-30K. Also the Differential Fluid is good to change, not a necessity, but it is good for long term if you have the money for it. It is simply take the cover off of the rear end, let the fluid drain out and clean mating surfaces and apply sealant and reinstall. Plug is in the front or in the cover. Fill until it runs a good slow stream out of the fill hole. If you want to try it yourself. That's about it. Along with oil changes regularly. Hope it helps.
  • IDLE AIR CONTROL VALVE or an intake leak. Check your hoses and make sure they are not leaking. 99% sure it is your IACV. They are a common problem. Hope it helps.
  • What is the mileage on your troop? If it is 60,000 or more I would change the plugs, oxygen sensors, and the egr valve. ALL of it can be done by you for much cheaper than the stealership can do for you. Even if you have to buy a $5 Oxygen sensor socket at Advance. Plugs are Cake. Make sure you blow compressed air down the plug holes as they collect dirt and crud down there you don't want going into your engine. Hope this helps. Oh, the sensors are all on the exhaust. You have 2 upstream(before the converter) and 2 downstream(after the converter) The 2 downstream are your catalyst efficiency monitors. They monitor how well your catalytic converter and EGR are doing the job of lowering your NOx levels in the exhaust. Did you have a check engine light? I have a hard time believing that 4 sensors were "bad" and it didn't even trip a check engine light. Also, the sensor which monitors how much exhaust is going through your egr valve might be bad. If it is generally it will do some weird things. You will usually get a INSUFF EXHAUST FLOW or EXCESSIVE EXHAUST FLOW DETECTED. Ford called it a DPFE sensor or Delta pressure feedback exhaust sensor. Might be worth a look. Generally throws a code though. Hope it helps.
  • n9pugn9pug Posts: 3
    after installing a vortex generator in the intake hose, and putting in a 4700 ohm resistor in place of the thermistor (IAT SENSOR ) I am getting 16 mpg combined town and highway. Has anyone got more or is this about the best it gets? I would like to get 20 mpg, any tips apprecaited......I have seen some websites where they give the mileage at 13.8 when it was new.
    LOVE MY TROOPER) ;) ;) image
  • I would be careful putting a resistor in place of the IAT. It adjusts the fuel/air ratio depending on the density of the air coming in the motor by reading the temp of it. Colder air has more density so you get more oxygen in it, which requires more fuel. Hot air has less, so you need less. Just be careful not to run it too lean or you will burn a valve or put a hole in a piston. The MAF determines the amount of fuel by how much it detects coming across it in conjuction with the density measured by the IAT. That's messing with some of the fuel maps in the computer. Just be careful. Gas is cheaper than a new motor.
  • n9pugn9pug Posts: 3
    thanks for the reply, the 4700 ohm resistor makes it think it is about 62 degrees outside, so I dont think I am running it too lean. Also, what about mileage? I am getting about 16mpg combined mileage. I have read where the NEW mileage was 13.8, so am I above average? I would like to try to squeeze 20 mpg out of it, think thats possible? .....greg
  • my trooper is running well and but i have few problems at the moment. at times ReABS indicators pops up, especially after driving and in a major impact/vibration. i thought it is in the Fuse in the front fuse box but very difficult to rule it out. secondly the Engine Oil pressure indicator is not working, but temperature and other relevent indicators are fine.any body can help me in this issue.
  • i had the same issue and did not take care it properrly. i was spraying belt dressings but one day knew it is from water fan. but it was too late. i had to replace water fan,radiator, tentioner,hoses etc. take care.
  • green11green11 Posts: 22
    Thanks for the advice. I was beginning to think my post would not get a response. I am definitely not doing the flush, but will strongly consider your recommendations.
  • i had my starter motor replaced by a mechanic and he took almost 45 min. he took out the exhast manifold and replaced the motor easily. you can do that on the ground.
  • What most people refer to a flush is really a fluid exchange using the transmission to draw / pump new fluid in. There are all sorts of stories that putting new fluid in will remove the varnish holding seals & tranny parts together in a neglected transmission causing a failure. The detergent properties in the new fluid will keep particulates in suspension. Personally, if the fluid smells burnt or is brown from heavy particulate contamination, I would change out the fluid. Continuing to run contaminated fluid will only promote more internal wear. Draining the fluid & pulling the pan for an inspection (including checking the screen) may be prudent then properly filling with ATF before the complete fluid exchange later is another option to insure the system is clean.
  • I have a leak that sounds the same as yours. What year is your Trooper. I have purchased the replacement line but have not had a chance to install as of yet.
  • I had a 1995 Trooper with a tiny power steering leak. The line with the leak is a sharp bend and it is known to fail after 120K miles or so. Expensive little hose to replace.
  • russlarussla Posts: 74
    TOD essentially locks when there is a speed difference sensed between the front driveshaft and rear drive shaft.

    So there could be a sensor issue, or you could have under/over ,between front and rear, inflated tires that cause enough difference to trigger the locking

    I would ensure that the speed sensors are well connected.
  • bock1bock1 Posts: 1
    I have a 1999 trooper that the engine races at 2000-3000 rpms. I have spent over $1300.00 at Isuzu dealers only to give up! It will race sometimes for the whole day or just a couple of hours. The dealer checked the cables and installed sensors but nothing works. Can anyone help me.
    Thank you.
Sign In or Register to comment.