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Discussion Starter · #1 ·
Still have not had time to go through it or start the cleanup. I am sure I will have a million questions. I noticed the fuse box did not have a cover and I know the cover tells what the fuses and relays etc. are for. I have a few empty slots and it may be for stuff this vehicle never had. Manual door locks and windows. Anyone know where I can source this missing cover?

BTW I think this is the original paint, does anyone know what it was? Beige? Yellow?

Thanks
Alan
 

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1989 Trooper R/S
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Nice find. Head gasket failures are fairly common on the 2.6 engine, especially if overheated. The number 3 and number 9 fuse counting from the right are missing on my 89 and the relay that's missing on yours, I think is for power windows, a feature that I didn't know was even offered on the Gen. one Troopers. Welcome here, a place where we're all friendly and helpful.
 

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Discussion Starter · #6 ·
Yeah I am hoping its just a blown head gasket but you never know when you buy a non runner. I hooked up a battery to it and all the lights and accessories worked. I did not hear a fuel pump buzz when the ignition came on. Assume these have an in tank pump? Can you hear it activate when you turn on the ignition like some do?
 

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giusedtobe said:
Thanks Ed! From that schematic it looks like everything is there. Assume I need to go salvage to find a cover.

Regards,
Alan
that is, IF you come across a first gen in the boneyard. They are getting harder and harder to come across..

check with Jerry Lemond, he used to have new ones for sale. he still might.
 

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giusedtobe said:
Yeah I am hoping its just a blown head gasket but you never know when you buy a non runner. I hooked up a battery to it and all the lights and accessories worked. I did not hear a fuel pump buzz when the ignition came on. Assume these have an in tank pump? Can you hear it activate when you turn on the ignition like some do?
Yes, they have an in tank pump. Some times a previous owner will have cut a hole under the back mat to access the pump, otherwise the tank has to be dropped. As to the head gasket, assuming the engine can be cranked, a compression check should confirm a blown head gasket.
 

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Discussion Starter · #9 ·
itsmehb said:
giusedtobe said:
Yeah I am hoping its just a blown head gasket but you never know when you buy a non runner. I hooked up a battery to it and all the lights and accessories worked. I did not hear a fuel pump buzz when the ignition came on. Assume these have an in tank pump? Can you hear it activate when you turn on the ignition like some do?
Yes, they have an in tank pump. Some times a previous owner will have cut a hole under the back mat to access the pump, otherwise the tank has to be dropped. As to the head gasket, assuming the engine can be cranked, a compression check should confirm a blown head gasket.
I haven't gotten that far yet but when I turned it over briefly it felt like it had no compression. I was using one of those jump start things not a dedicated battery so I'll certainly do a compression test before I dig in. PO did cut a square out there which I would prefer he hadn't. I probably should be thanking him though because I have dropped tanks before and I know it can be a pain, especially if it has a lot of fuel in it.

I'll contact Jerry to see if he has a fuse box cover he will sell. Thanks for the help guys, I will post more as I get further into it.

Alan
 

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Discussion Starter · #10 ·
Gave it a quick wash to see what it looked like under the dirt and slime. I think the paint will actually buff out but that is a concern for another day. Going to check the compression tonight and check the fuel pump etc.

Before and after but hard to tell from the pics the difference.
 

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Nice one! The fuel pump should only run when A: You are cranking the engine over (to start it) or B when the engine is running. It will not run by just turning the key on. At least that is how it is on my 89.
 

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Correct. The ITEC system requires a cranking signal (from the distributor) to energize the fuel pump relay and fuel pump.

BTW for testing/troubleshooting you can bypass the relay by removing it and jumpering the appropriate terminals.

Attached is the ECM wiring diagram for an '88-89 Trooper 2.6 ITEC.
 

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Discussion Starter · #13 ·
Its got like 20 psi compression in number 1 :(

No need to test the others, head has to come off. From my limited experience this sounds exactly like how my 88 Nissan Sentra sounded turning it over after the timing belt broke while driving. From the guys description of how the "head gasket blew" it sounded identical. I was in the Army then and had a tank mechanic fix it on the side. Car was never the same after but this one sounds exactly like that one did when I turned it over on the side of the road and then later learning the timing belt had broken. Kind of like just windmilling with no compression.

Hopefully I am wrong and there is no piston or valve damage.

Good thing I already ordered a head gasket!
 

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Good thing I already ordered a head gasket!

Hopefully the head gasket is a fel-pro or an OEM gasket. Others have failed prematurely. In fact I'll say I've done four head gaskets, one on the 1.9 engine, one on a 2.3, one on a 2.6, and the other on a 2.2 in a 2000 Amigo. I used one OEM and the other 3 were fel-pro's. All 4 turned out good. Also, you should replace the water pump and timing belt and tensioner while your there, along with new water hoses and vacuum lines.
 

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Discussion Starter · #15 ·
itsmehb said:
Hopefully the head gasket is a fel-pro or an OEM gasket. Others have failed prematurely. In fact I'll say I've done four head gaskets, one on the 1.9 engine, one on a 2.3, one on a 2.6, and the other on a 2.2 in a 2000 Amigo. I used one OEM and the other 3 were fel-pro's. All 4 turned out good. Also, you should replace the water pump and timing belt and tensioner while your there, along with new water hoses and vacuum lines.
Too late on the gasket. I suppose I am being negative but I am prepared for the worst in that if a new head gasket and some head work gets it running I am going to want to rebuild it anyway. GOing to have to figure out all those vacuum hoses and their functions. Never seen so many. I have a shop manual coming so I did not want to ask too many stupid questions too soon.

I will ask one though: What the heck is that circular metal tube that attaches to the exhaust manifold? Assume part of the emissions stuff.

Alan
 

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The tube is for the EGR. There are 2 ways to pull the head; since the intake is almost impossible to remove in the vehicle, pull the intake and exhaust manifold together with the head. You'll need a strong helper or engine hoist/comealong. To make the assembly a bit lighter, remove the exhaust manifold. Probably a good idea to pre-spray the EGR tube's nut at the manifold and let it soak for a few days.

One thought, before teardown: any possibility of getting it to run? Even if it runs on 3, you'll be able to check oil pressure, listen for noises, warm up to temp and check for white smoke blowing out the exhaust.

Any signs of water in the oil or oil in the radiator? That's a good indication of blown head gasket or cracked head.

If the gas tank isn't too crudded-up, you may be able to drain it then put fresh gas in. Check for a drain plug, most tanks should have one. You can easily pull the fuel pump and take a peek into the tank. Maybe even replace the fuel pump if it's shot.

Here's a pump kit, built in Japan, for under $30 on eBay:

https://www.ebay.com/itm/KEMSO-340LPH-H ... SwXIhbjjiv

This one should be better than an unreliable Airtex or generic Chinese junk.

On the low compression, I'd still check the other 3 cylinders. If, for example, compression is also down on #2, it's most likely the head gasket metal fire ring is blown between #1 and #2. If only #1 is low, more likely a burnt exhaust valve. Check valve clearance and if it's tight, readjust to .010" and check compression.

It's very common to see burnt exhaust valves on earlier models, since they had production issues. Add a lack of proper valve adjustments by previous owners, and there ya go!

Typically you'll get head gasket and burnt valve failures on cylinders 2 & 3 or 3 & 4, but stuff happens! It'd be good to know what's going on before teardown.

Anyway, just a thought, HTH...........ed
 

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Discussion Starter · #17 ·
Thanks for the tips. Good advice so I will go ahead and check the other three to be certain instead of going off my memory of how one with a broken timing belt sounded 25 years ago. Not sure if you can get video on here or not but I will see if I can video it so you can hear it. It sounds like a sick pup spinning over.
 

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giusedtobe said:
Thanks for the tips. Good advice so I will go ahead and check the other three to be certain instead of going off my memory of how one with a broken timing belt sounded 25 years ago. Not sure if you can get video on here or not but I will see if I can video it so you can hear it. It sounds like a sick pup spinning over.
It may have more than one bad valve (or other problem), sounds like it. If you pull the distributor cap while you're cranking, you can see if the rotor turns. Or I supposed just pull the oil fill cap on the valve cover and see if the camshaft turns.

Got Spark?? :mrgreen:

No doubt, if the timing belt broke, the head's gotta come off. This is Most Definitely an interference engine. If it's only crunched valves, they're easily replaced. Have the machine shop do a valve grind, or quick-n-dirty just lap in the new valves with some Clover valve grinding compound, if the valve seats aren't in too bad of shape. Rockauto has some decent deals on aftermarket valves. Isuzu OEM valves are better, but they are REALLY expensive!

If it's the head or gasket issue, you're gonna have to get that head pressure-checked before doing anything. You can't trust 'em. Last time I did a head, I had to replace all the valves & exhaust guides too. With pressure-checking and milling, it was quite expensive. Coulda bought a new head by the time I was done. Machine shop prices have gone up astronomically since then.

Unless you've got a good buddy with a machine shop!
 

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Discussion Starter · #19 ·
OK before I keep butchering the cylinder numbers is cylinder 1 closest to the firewall or closest to the radiator? Either way I've compression checked both 1&4 and they both barely register so on to head removal. Maybe I will get it done this weekend if my honey-do list is not too large.

I was counting on more than likely needing to have some machine shop work and unfortunately I do not have a buddy that works in a shop. Kind of wondering if it would make more sense to just replace the head if it is likely to be a wash with them reconditioning the current one. I am sure at a minimum, I will be out some dough just to have the machine shop evaluate the head. Then if they have to do extensive work it might make more sense to source another one.

I've seen websites offering 2.6 Isuzu 4 heads; are they reconditioned I assume? Any tips on the best places to acquire one of these? I have seen several people mention on this site a head with a tear drop shaped combustion chamber. What is the story on these? If I have to replace I'd rather make changes along the way that will increase performance if possible.

Regards,
Alan
 

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#1 is at the front and #4 at the firewall. The later-style "heart-shaped" cyl head, along with a change in pistons to match the new shape of the combustion chamber, was mostly for emissions purposes.

However, when you throw one of these heads on an older engine with "flat top" pistons, it does bump up the compression a bit. Conducive to adding performance as per recent posts here.

Sounds to me like you've got burnt valves. Or maybe a combination of burnt valves and a blown head gasket, who knows. Might be productive to ask the P.O. what made him think the head gasket was blown. If it's just poor running (from the low compression), and not overheating/white smoke/fluids where they shouldn't be, then maybe it's just a valve thing.

Very remote chance of piston/cylinder issues but the bottom ends on these are pretty stout, except for the thrust bearing issues we talked about prior. Mostly they suffer upper-end problems.

Here's a brand-new bare head on eBay for $345 shipped:

https://www.ebay.com/itm/Isuzu-2-6-SOHC ... SwjVVV15xO

You'd need to install new valves and build-up the head with the rest of your valvetrain. A good time to add a performance cam, too!

Jerry Lemond is also a good source of parts, you might give him a holler to see if he has any of these heads in stock. Username on this forum: JLEMOND

For a low-buck$ solution, check at http://www.car-part.com

I found a number of '94-97 Rodeo/Passport 2.6 heads around the country, for pretty decent prices. and what you'd get from the wrecking yards would be the entire head assy, valves, valvetrain, cam, etc. Can't hurt to check around, you may find a good deal with one of those. There were a few listed for a '94 Amigo as well, even cheaper.

The newer heads are far less likely to have cracking issues than older ones (such as your '88). ZuZu upgraded the head castings with a better design, when they changed the cyl head style.

And while it may be relatively safe to buy a used/remanufactured newer-style head, NEVER waste your money on a used open-chamber head. You never know when you're gonna get one that's either cracked, or ready to crack. And there's no guarantee that a remanufacturer won't have welded-up one of the older heads, which is just asking for trouble.

Almost time for the autopsy, have fun!
 

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