20 Most Recent 1998 Isuzu Trooper Questions & Answers

NO car told at all, maker model and enigine there. what side does the driver sit, left or right , in USA ,its left. not told if clamp is stock powerful and good OEM spring loaded clamp or these cheezy screw drive clamps sounds to me like 2 causes 1: yes clamp is bad. 2: engine has exhaust gases in the coolant,. (blown head gasket) or worse warped head or cracked head. worse can go more. worse. a $1 fix or $1500 fix. why not ask a real shop to check it out. they can a radiator leak down test in a jiffy, a cheap tool we all have. knowing what is or having #2 get worse and blow up a $3000 engine is not wise. find the truth then play the cards. avoid cascaded failures get it tested by a real shop. normal pressure is about 14psi, or 1 bar. the rad cap regulates that and does not blow off hoses with good clamps. but if #2 happens all bets are off.

Hi Markq,
Seems you may have a similar problem on your machine to the one we've had....The 4JX1 has taught us a lot we didn't know before, but specifically for this particular engine. First I'll advise you check the obvious things...Make sure that your battery is charged fully. I'll explain why later. Next make sure that there's no air in the fuel system....On the filter housing you'll see a ten millimeter bolt, which should be loosened and once loose push the plunger atop the housing to remove any air....If bubbles come out you'll know that that was the problem or part of it. With this particular engine the ORPS (sensor) gives the type of problems you're talking about. The sensor in question is fitted inside the tappet cover into the oil rail (which is the cylindrical pipe fitted over the valve assembly....It has two sensors, one being the ORPS and the other being an oil temperature sensor. To get to these it'll mean removing the tappet cover which means first removing the inter cooler....then the oil feed pipe which fits into the side of the cover, Remove all the screws (five each side and three at each end)....The ORPS is the smaller of the sensors....It is a sensor which operates with a crystal....The oil pressure pressing against it will cause a very small voltage which is actually a pulsed signal....That signal is sent to the management computer and controls the solid state switch which allows the circuit for the injectors to become active....Remember the battery? If the battery is not able to turn the engine at what you'll hear as a normal speed the oil pressure will not be enough to send the signal which opens the injectors....The ORPS (Oil Rail Pressure Sensor) cost's about two hundred and twenty US$ and if you do the job yourself your probably save a similar amount on labor charges....The engine oil is also critical....Only use the recommended oil....If that has not been used....Buy double the amount of the correct oil and two of each filter....Drain what's there and then refill with the recommended oil (once vehicle is up and running) run the engine for thirty minutes or so (pref on the road) and then re drain and again fit the other set of filters and refill....We don't like the chemical engine flush additives, too dangerous, especially in a diesel engine.... Hope this is help Markq Let me know how you get on. you can send your reply to this same web site...I'm one of the experts.... Cheers for now.... Best regards Johngee10

This is typical of o-ring "seals" in the injector systemof the 4JX1 engine losing seal quality which will mix oil and coolant together and return both into the fuel tank and radiator. Smell the radiator. Most likley will smell of diesel fuel and perhaps show oil if you dip a timber ice cream stick into the radiator. Often occurs after overheating (towing or low on coolant). Buy an electric "ratchet" pump on eBay if you are going to fix the injectors [1 0-ring] yourself (and the sleeves [2 o-rings] per cylinder. You need a sleeve removal tool also. Instructions are available on Australian 4WD forum. The pump is to pump out of the fuel tank before you start the job. Take the input fuel line and hook into the pump. A plastic tube of the right size onto the outlet side and energise the pump. Drain into a 2 litre container(s) until diesel shows up instead of water. Drain the coolant before starting the engine repairs as some coolant pipes are made with rubber component pipes and could deteriorate if left too long. You need a copy of the manual (free online - do a search). You need to tighten the oil rail and injectors to the routine given to ensure good sealing. New copper washers for the injector ends are essential for good sealing. Ive had good results from using old rings for sizing and replacing with Vitane o-rings from hydraulic supply dealers. Label clearly when purchasing. Do not use standard rubber as they are not temperature rated. O-ring on internal injector plunger is "ceramic" and is not feasible for normal repairers and is usually not required. .RichW

Jack up the wheel ,take off the allen screws (no oil) then see a locking ring with 3 cross head screws which will be very tight. take them out turn the adjusting ring cockwise and spin the wheel till the play is gone then get the next set of holes in line so there is a tiny bit of load on the bearings and bolt it back up - job done .

Get some BLUE DEVIL and follow the Directions. You have a Blown head Gasket or a Cracked Intake or Head.

Try fitting a seperate transfer pump between the tank and HP pump(quick/cheap fix only) and see if this resolves the problem. If yes check filler cap(no air lock), air leaks in supply hoses or transfer pump(and of course the usual "check the fuel filter").
If not, dig deeper:


J-1-15(not indicated) : Earths glow plug relay to enable glow plug circuit.
ECM : Electronic control module
IS : Idle switch
ECT : Engine coolant temp
OTS : Oil temp sensor
IAT : Intake air temp
FTS : Fuel temp sensor
INJ : Injectors 1 through 4
RPS : Rail pressure sensor
EGR : EGR vacuum pressure
MAP : Inlet manifold pressure
APS : Accellerator position sensor

You need to replace the filter in the transmission and clean the body valve add new oil ,I do believe this transmission need it,all the best.

Go to my profile I have just explained how to change a cv boot on a Trooper. The axle needs to be taken out to change the boot so the same solution. What you call an axle I have refered to as a drive (short for driveshaft) It takes a lot of explaining so save me a lot of writing if you read the solution I gave for changing the CV boot. Cheer's

Sends a signal related to the rail pressure as a voltage to the ECM. 3 wire connector :

• Red : 5V (Feeds from ECM connector J1-4) Shared with MAP sensor, EGR pressure sensor and accellerator position sensor.(compare values from these sensors and ECM connector)
  
• Black : Ground (Feeds from ECM J2-22) Shared with the same sensors mentioned above
• White : Signal feeds to ECM connector J2-22

Low pressure will set P1194 error code. Oil rail pressure should be more than 3MPa when cranking

Also check Engine coolant temp sensor and wiring. Engine coolant to manifold temp should not differ by more than 5 deg C either way after 8 hours of no operation. I have found the same symptom on these diesels with fuel supply problems. Operate the priming pump (on top of the fuel filter) until it becomes diffycult to push down before starting or checking anything else.

identify the oil leak location and replace the gasket where the leak is originating from.

in he alternator

I think you should buy repair manual first for your vehicle after that it will be easy for you to solve the problem. Check the link may be you will find something useful here 1998 2002 Isuzu Trooper Service Repair Workshop Manual DOWNLOAD

Close the EGR, check whether still noise is there.
If so EGR regulator has to be replaced

On the next "above freezing" day, force lubricant through the throttle cable and lube all linkage at the engine end and interior.AND BEFORE STARTING for the next while try depressing the gas pedal and make sure it is releasing fully. If it ever gets stuck again SHUT IT OFF before you damage the engine with high RPM on a cold engine.

no engine stated. details are based on that.. so is it still the old pump there, this is very simple using a volt meter. (the pump has 2 wires, measure across those) back probe that connector to the pump. 2 pins. 12vdc cranked, if you have 12vdc cranked but fuel pressure is 0 the pump is gone no pump runs on 0v, or 6v, its 12vdc there, i can not understand those fues tests if the voltage fails to the pump it can be the power wire or ground wire failing . do all tests connected, or the readings will be useless. connected is live testing, under full real conditions and win. every time. if ground is tested and rises to 12vdc cranked, ground is bad. only Ohms laws here,a simple equation. not sure why your float fails. my guess its bad. and easy test using ohms, disconnected. that is another problem. ill look at your fuse, pretend V6 engine. the service manual shows f10 fuse is fuel pump 12vdc both side cranking is a GOOD FUSE. note all words above. F10 gets all power from pump relay, so if you dont crank the relay can be off line an F10 will be dead. (the schematic is clear) here is a facts on all cars, next (pure software in PCM )

1. pump only runs 3 seconds key on, ,
2. pump never runs, if not cranked.
3. run cranked and all run if engine stays running.

see? and varies by year, engine, and even ECU upgrades so a SAVVY mech always cranks to do tests. that means its a 2 man job. sorry but that is a reality of working any car until you learn what yours does. warning have a care here that changes rule 1 to 2, below 20F out door temps, (fun no?) recap crank and measure like this. the pump has 2 wires, red hot, black ground meter across, pins 1 to2, red back is 12vdc cranked meter black tests lead (volts) to body perfect metal ground and meter red lead to pin1 red shows, 12vdc cranked 12vdc means 10 to 12vdc cranked, (battery does that) then move red test lead to pin 2, black cranked, 0v, if see 1 volt or ore the ground called.B26 is bad. if the pump has 12vdc on it, you hear it, do not run it dry its fuel cooled and fuel lubricated or you wreck it. if it is heard to run you then see fuel spec fuel pressures. or its bad. (30psi?)

lost the operators guide. and guess what, many have asked, 1000s if you google. ever like google>? omg, the first hit, I guess, my keyboard, is better.... http://forum.planetisuzoo.com/viewtopic.php?t=44025 why not buy the manual,

run the fault codes and check for crank/ cam position sensors broken timing belt, fuel problems diesel check for air in the fuel system