Isuzu SUV Forum banner

95 Trooper Repair and Improvements

58K views 152 replies 18 participants last post by  SupATro.0pA 
#1 ·
I recently acquired a 95 Trooper manual 4x4 with a 3.2 v6. The little Trooper gets a warm when idling at stops, and the mechanic for the previous owner suggested that the head gasket was blown. When I checked it for 4/5 of the tale-tale signs for a blown head gasket before acquisition, I found that it didn't have any of them.

  1. Bubbles in the radiator when running? nope[/*]
  2. Water vapor coming out of the tailpipe when running warm? nope[/*]
  3. Milky Oil? nope[/*]
  4. Copious amounts of radiator fluid spilling over the blocks from the headers? nope[/*]
  5. Spitting radiator fluid out of spark plug holes when turning over the engine? didn't check before purchase[/*]

I later pulled 5/6 of the spark plugs (the one right by the master cylinder is a real booger), and saw no fluid splashing out when I turned the engine over.

My thoughts are that it is either the radiator or the water pump (although I'm still looking to see if it's actually consuming water somewhere).

I did a heat test with the radiator by running the engine for a bit (drove thrice around the block), then turning it off, and feeling for cold spots with my hand, and found that about a third to a half of the radiator was cold. I've pulled and flushed the radiator, flushed the block, washed off the outside of the radiator and ac intercooler, installed a new thermostat, installed a new upper and lower hose, and am waiting for the sealant around the thermostat to cure before pouring in fresh fluid.

While I was waiting on the engine to dry, I pulled off the throttle body and cleaned it up a bit as well.

I'm hoping this does it. I'll try to get some pictures, or be better at taking pictures for future posts. This Trooper has plenty to work on, so I'd like to add to the knowledge bank as I go, and hopefully help somebody else out in the process.
 
See less See more
#2 ·
thats what I would have done first, shops like to jump to expensive repairs first and I dont. there are some threads on here that also sight the radiator as the culprit for you problems as the cooling fins get corroded and age they dont transfer heat well. Also check your fan clutch as it will cause idle overheating by not drawing enough air past the fins.
 
#3 ·
I'll definitely have to check on that fan clutch. That's a good idea. I'm a believer in putting nice things in the engine, so once I'm confident that this is running well, I'll probably look into replacing/upgrading it.
 
#4 ·
Put water in the radiator. Started it up. The engine starts better with a cleaner throttle body. The engine looks like it's cooling better, but I still have a cold spot on the radiator. Will be ordering a new one soon.

Two more trouble spots I found:

When running the motor in the driveway, smoke started coming out from under the font driver side. I dropped down to find smoke coming off of the area of the exhaust joints before the cats/mufflers. :shock: Turned off the engine, dropped under the car, and there are these oily wires sitting right on the exhaust pipe! :evil: Couldn't find a zip tie, but I found some plastic based string (nylon??) and tied it so that it wouldn't sit on the exhaust. Smoke problem gone! :king:

The Trooper's RPM's drop low at idle (and it stalls out sometimes during this). :? After a little research, I'm 90% sure it has to do with the huge gash in the intake hose that's wrapped in clear box tape that I may or may not have moved around when cleaning the throttle body. Have you seen intake hose prices? They must be riding the FJ bubble. Off to find some epoxy.
 
#5 ·
Haha. I picked up a descent ford probe back in he 90's for $100 because when you put it in drive and gave it gas the engine stalled but would run all over the parking lot in reverse. turns out a split in the intake boot/hose opened up when the engine rocked back when put in drive causing the stall. i fixed it with blue glue and electric tape then sold it for a tidy profit.
 
#6 ·
After a few days of puttering about, the engine seems to be running cool even with the cold spot. I'm going to drain it again and run some vinegar through the system for a few days to see if I can get the blockage out.

Epoxy seems to be working well for the air hose. There was about a mile of electrical tape on it, covering not one, but two massive tears in the hose. I'm still seeing the occasional drop in RPM's at idle, so I may add a second layer of epoxy.

I was looking at my internal fuses the other day, and can't make high or low of it. I don't have a cover with a diagram, and the fuses that are in there don't seem to match the list in the owner's manual no matter which way I read them out. As soon as I find an image, or at least the proper order, I'll post a diagram of it. Speaking of fuses, the spot for the 40amp ABS fuse underhood seems to be missing a post... :shock:

I've found a few pick and pull junkyards in the areas with Troopers in them ( :D / :cry: ). I may go see if I can pick up some cheap parts.

Here's all the things that don't work/need attention on this little truck thus far:
  • Radiator[/*]
  • Intake hose[/*]
  • Turn Signals don't work, no lights, no clicks (but hazards do)[/*]
  • No AC, supposedly compressor is out[/*]
  • Speedometer doesn't work, needle doesn't move an inch[/*]
  • Wiper sprayers don't work[/*]
  • Will need new tires soon[/*]
 
#7 ·
It's a 21 year old radiator, and a new one is less than $100...my 95 has been cool in all situations (even rock crawling in the desert) since I swapped in a new radiator.
 
#8 ·
SupATro.0pA said:
After a few days of puttering about, the engine seems to be running cool even with the cold spot. I'm going to drain it again and run some vinegar through the system for a few days to see if I can get the blockage out.

Epoxy seems to be working well for the air hose. There was about a mile of electrical tape on it, covering not one, but two massive tears in the hose. I'm still seeing the occasional drop in RPM's at idle, so I may add a second layer of epoxy.

I was looking at my internal fuses the other day, and can't make high or low of it. I don't have a cover with a diagram, and the fuses that are in there don't seem to match the list in the owner's manual no matter which way I read them out. As soon as I find an image, or at least the proper order, I'll post a diagram of it. Speaking of fuses, the spot for the 40amp ABS fuse underhood seems to be missing a post... :shock:

I've found a few pick and pull junkyards in the areas with Troopers in them ( :D / :cry: ). I may go see if I can pick up some cheap parts.

Here's all the things that don't work/need attention on this little truck thus far:
  • Radiator[/*]
  • Intake hose[/*]
  • Turn Signals don't work, no lights, no clicks (but hazards do)[/*]
  • No AC, supposedly compressor is out[/*]
  • Speedometer doesn't work, needle doesn't move an inch[/*]
  • Wiper sprayers don't work[/*]
  • Will need new tires soon[/*]
I don't think I've ever bought an Isuzu that had a working washer pump. These are cheap and universal, if I remember correctly.

Try another flasher unit to get your signals working. You'll be rewarded with the Trooper's coolest feature: the "flashlight" that comes on in the corner flashing. Very helpful at night!
 
#9 ·
I tried replacing one the relays, but no dice on the turn signals.

I visited a salvage yard this past weekend and FINALLY found a fuse box cover. I'll post a picture later for future reference. Somebody before me had just jammed different fuses in the box, so it was confusing to figure out at first. Fuses are now all in the right order and location, but no turn signals.

On a related note, the backlight to my gauge cluster is now gone. Driving manual by ear suddenly makes more sense.

I did some freeway driving this weekend, and saw the temperature fluctuations that the previous owner had mentioned. Temperature moves up 3/4, then suddenly kicks down to normal, as if something suddenly opens or starts working. I replaced the thermostat, so I know it's not that.

Picked a fan shroud up from the salvage yard, which seems to be helping the engine cool better. Blockage in the radiator + no fan shroud. No wonder it was heating up.

All the little electrical gremlins and cooling aside, it seems to run strong, so I've got that going for me.
 
#10 ·
IIRC the dash lights are on the same circuit as the tail lights, might want to check if those are working.
 
  • Like
Reactions: SupATro.0pA
#11 ·
I pulled a fuse cover from a 98 Trooper this past weekend (I figured they'd probably be the same). Playing with my fuses, and looking at my manual, this looks to be right. Which one of these would be for the taillights?

 
#13 ·
I found it. The tail light fuse for a 1995 Isuzu Trooper is under the hood. Evidently the Rodeos had them in the dash fuse box. The fact that there is also a Tail Relay under the hood didn't help me find it any quicker.

15amps and blown. I did hook up the radio recently, so that might be part of the issue.
 
#14 ·
check out my photo in this post. viewtopic.php?f=1&t=87261,

an intake hose from a 93-95 V6 rodeo/passport will fit just fine and isn't made of same material so it doesn't crack as easily. just make sure you use the hose clamps from the rodeo/passport. I got mine at a pick n pull for less then $10
 
  • Like
Reactions: SupATro.0pA
#15 ·
That's great! I'm going have to keep my eyes peeled next time I go to the yard.
 
#16 ·
I've found the issue with my turn signals. The spot of the fuse box for the turn signals is pretty torn up. It looks like a fuse melted the box there at one point. Upon removing the fuse box, I've found a bit of shady wiring in the back. Two different wires crimped to a flat piece of metal and shoved into the back of the fuse connection of fuse C3. One of the wires has duct tape on it.

I bought an external fuse case, plugged in a 15 amp, took the two wires off and connected them to the new fuse case, hoping for working turn signals.

No dice.

Now I lack turn signals and working power windows. The 30 amp Power Window breaker doesn't appear to be tripped either (the tab is still pushed in). I'm going to rewire to see if I can't get the power windows back, then maybe look at the wires and schematics a bit better to see what is going on.
 
#17 ·
I ended up reconnecting one of the wires to the back of the fuse box via the piece of metal that was holding it in place before, while leaving the other wire hooked up to the new 15 amp fuse. My windows work again, but my turn signals do not.

I had to settle with the windows and not the turn signals because Labor Day Weekend was a big camping trip, and the Trooper was a gear moving vehicle for that. 7 hours in a questionable Trooper deep into the mountains.

Here's what the Trooper revealed on the journey:
  • Either I had a bad Throttle Position Sensor, or a vacuum leak somewhere (I recognized that I was not getting the air while still getting the gas, or what some people call a loss of power) :evil: [/*]
  • It's consuming fluid somewhere. I had to fill it up once. I've been getting some water vapor out the tailpipe when starting cold, and even when the engine was warm, but being in a coastal area, I am hoping that it is just condensation in the tailpipe, because once it warms up, there is no vapor. It cools strongly until it runs out of fluid, if you would believe that. :shock: [/*]
  • My suspension is softer than I thought :? [/*]
  • 4 wheel drive works :mrgreen: [/*]
  • A queen sized air mattress fits perfectly in the back (who needs a tent?)[/*]
  • The cold spot might be gone from the radiator (I need to double check this) :D [/*]
  • A stall prone, loaded down, soft suspension, manual Isuzu Trooper going up a single lane mountain road with a driver who's only been driving stick for two weeks is comparable to the Indiana Jones Disneyland ride. [/*]
  • The Trooper can survive 7+ hour road trips like a champ :king: [/*]

I pulled a TPS and main air intake hose from a 3.2 Honda Passport from a salvage yard, but that did not seem to solve my issue of the Trooper stalling when I throw it into neutral to coast into a stop. I purchased some lengths of hose, throttle body cleaner, and a new throttle gasket, and am now going to town on my air system. Hopefully this resolves my idle and power loss issues.
 
#18 ·
Either I had a bad Throttle Position Sensor, or a vacuum leak somewhere (I recognized that I was not getting the air while still getting the gas, or what some people call a loss of power) :evil:
Intake manifold gaskets are worth a look here, but given your Trooper's history you might want to verify all the vacuum hoses are intact and in place.

It's consuming fluid somewhere. I had to fill it up once. I've been getting some water vapor out the tailpipe when starting cold, and even when the engine was warm, but being in a coastal area, I am hoping that it is just condensation in the tailpipe, because once it warms up, there is no vapor. It cools strongly until it runs out of fluid, if you would believe that. :shock:
Condensation out the tailpipe at start is normal. I assume you've pulled the dipstick to check for coolant in the oil?

My suspension is softer than I thought :?
Yeah, the factory suspension was calibrated for soccer moms. OME coils are a big improvement.

4 wheel drive works :mrgreen:
You have the automatic hubs? If you are going to off-road with any seriousness you might want to swap in some Aisin manual hubs. They are much stronger and won't unluck when you reverse trying to get out of a mudhole.

A queen sized air mattress fits perfectly in the back (who needs a tent?)
I sleep in the Trooper, very snug in inclement weather. And you can get magnetic screens for the windows from places like Skeeter Beater.

A stall prone, loaded down, soft suspension, manual Isuzu Trooper going up a single lane mountain road with a driver who's only been driving stick for two weeks is comparable to the Indiana Jones Disneyland ride.
That does sound exciting...mountain driving can be challenging at the best of times.
 
  • Like
Reactions: SupATro.0pA
#20 ·
BigSwede said:
Either I had a bad Throttle Position Sensor, or a vacuum leak somewhere (I recognized that I was not getting the air while still getting the gas, or what some people call a loss of power) :evil:
Intake manifold gaskets are worth a look here, but given your Trooper's history you might want to verify all the vacuum hoses are intact and in place.
I just threw a new one of those on, as the old one disintegrated as I cleaned out the throttle body.

BigSwede said:
It's consuming fluid somewhere. I had to fill it up once. I've been getting some water vapor out the tailpipe when starting cold, and even when the engine was warm, but being in a coastal area, I am hoping that it is just condensation in the tailpipe, because once it warms up, there is no vapor. It cools strongly until it runs out of fluid, if you would believe that. :shock:
Condensation out the tailpipe at start is normal. I assume you've pulled the dipstick to check for coolant in the oil?
I changed the oil a few weeks back, and it looked like regular oil. No foam. No grey.

BigSwede said:
My suspension is softer than I thought :?
Yeah, the factory suspension was calibrated for soccer moms. OME coils are a big improvement.

4 wheel drive works :mrgreen:
You have the automatic hubs? If you are going to off-road with any seriousness you might want to swap in some Aisin manual hubs. They are much stronger and won't unluck when you reverse trying to get out of a mudhole.

A queen sized air mattress fits perfectly in the back (who needs a tent?)
I sleep in the Trooper, very snug in inclement weather. And you can get magnetic screens for the windows from places like Skeeter Beater.
Adding these three items to my extended to do list. Thanks!

BigSwede said:
A stall prone, loaded down, soft suspension, manual Isuzu Trooper going up a single lane mountain road with a driver who's only been driving stick for two weeks is comparable to the Indiana Jones Disneyland ride.
That does sound exciting...mountain driving can be challenging at the best of times.
How else do you make memories?
 
#21 ·
I changed all but one vacuum line (little one to the left side under the fuel line, and crammed between covers) and cleaned out the throttle body, IAC Valve, IAC Valve connector, TPS, and TPS connector. I have significantly more power at my lower RPMs, but am still experiencing stall outs when shifting into neutral, and power loss at 3rd/4th/5th gear.

It's weird. There is a power loss, I recognize that it's not getting air, then something shifts, and I suddenly get power, followed by a check engine light. When I lose power, it's like something lags or turns off, and the check engine light goes away, along with my performance. I'm about to test the TPS and TPS wiring.
 
#22 ·
I tested the TPS according to the instructions on this site http://easyautodiagnostics.com/isuzu/3.2L/throttle-position-sensor-tests-1. The first test showed that the TPS should be working. I had a friend turn on the engine and push on the throttle pedal so I could check the throttle cable but a lovely plume of black smoke soon filled the neighbor's front yard pointing to a new issue. :tard:

My first thought was a bad catalytic converter. A little further research has me cleaning out the EGR valve, with plans to buy a new EGR valve gasket, Fuel Pressure Regulator, and Fuel Filter in the morning (might as well cover all of my cheap bases). If none of those things resolve the fuel consumption, then I'll see about cleaning the cat. All of these options should potentially solve my idle and power loss issues.

As for the cooling system, a friend suggested dropping a piece of rubber on the fan to see if the fan clutch was catching at higher temps. Evidently if it's not catching, you can stop the fan from spinning without much effort, as it won't be locked into the engine. I was able to stop it while idling after a run on the highway, but I may test this a few more times before replacing it. I'll probably drop in a new water pump and timing belt at the same time if I do replace it.

There's still a cold spot on the radiator, so I'm going to concede defeat to my cheap solutions, and get a new one. :blackeye: The vinegar did clear out a lot of gunk though.
 
#23 ·
SupATro.0pA said:
I did some freeway driving this weekend, and saw the temperature fluctuations that the previous owner had mentioned. Temperature moves up 3/4, then suddenly kicks down to normal, as if something suddenly opens or starts working. I replaced the thermostat, so I know it's not that.
i would change your upper and lower radiator hoses. It might be collapsing under throttle. Get it up to temp, and rev up to 2500-3k or so and hold it there from throttle body and see if the hose is collapsing w/ throttle. That would explain the overheating, then sudden drop in temp. As the hose collapses it shuts off circulation and gets hot, then you get off the throttle and hose returns to normal flooding the engine w/ cold coolant dropping temps fast.
 
#24 ·
I can help with a couple of issues, since I had them on my '95.

1. The problem with the windshield washer is probably due to a bad filler tube. The tube runs down from the filler by the battery to the bottle by the passenger side fender. I ended up replacing the assembly with a new one from Jerry Lemond. You get to it by peeling back the plastic inner fender. Have someone pour in some water and see if it is leaking out. On my '95, the flexible tube was full of cracks.

2. To firm up the ride, I added Moog Cc812 springs in the rear (viewtopic.php?f=1&t=87959&p=775973), HD torsion bars in the front (with about 1" of lift) and replaced the worn shocks. Also eliminated some play in the steering by replacing worn ball joints and tightening the steering box. The 812s were only $100 on Amazon. Don't know if I really needed the HD torsion bars -- cranking the stock bars an inch would firm them up -- but I picked them up because Indy was down to the last 5 sets and didn't know if they would ever get another shipment.
 
#25 ·
Have you ever checked the codes? You've said several times that the CEL is coming on telling you there's a problem but I haven't seen any codes listed. Seems more a little silly if you're just throwing parts at it hoping something gets fixed. As for your fan clutch just spin the fan by hand with the engine off. If it free spins then it's bad. If it starts to tighten up then it's good. No need to shove anything in it while the engine is running.
 
#26 ·
nasty610 said:
Have you ever checked the codes?
The 1995 is an odd ball. It is pre ODCII. There is a hatch to the right of the steering wheel with 3 plugs in it. One is for the ABS and requires jumping 2 pins to get the ABS codes to flash. One of the others is for the engine but you can't hook up a standard code reader. Don't know if there is a way to jumper it to get the codes.
 
  • Like
Reactions: SupATro.0pA
Top