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Discussion Starter · #1 ·
Maybe someone here can point me in the right direction:

As a few of you probably know, I've been putting a 2.8 into a '91 pickup, and have found that the motor has some problems. Before I go any further (pulling it back out, complete teardown and rebuild, re-install) I'd like to get some information on this creature, so I have all my **** in one sock and won't have to hunt for information when I'm putting it back together and dropping it back into the pickup.

Things I need to know:

Timing procedure (firing order, etc.)

Torque specs on everything

Valve lash adjustment procedure (if any...having pulled the valve covers yet, don't know if it's non-adjustable)

Source for cheap parts

How to I.D. this particular block so I can be sure I'm getting the correct aforementioned cheap parts

So, if any of you Isuzu-Experienced gents could point me in the right direction, I'd appreciated it.
 

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Firing order is 123456
head torque is 40 ft lbs plus a 1/4 turn
main bearings 70 ft lbs
rod caps 39 ft lbs
Parts are relatively inexpensive anywhere as it's a GM engine. I often check www.rock-auto.com as a comparison, then either order there or buy locally.
Valves are hydraulic and adjustable. Bring the cylinder up to top dead center, loosen the rocker and slowly tighten it while rotating the push rod. When the pushrod no longer easily rotates you've removed the lash, then tighten an additional one to one and a half turns to center the push rod in the lifters travel.
Have to wonder what problems you are having? If you in fact rebuild this engine there is a ton of additional information you'll need / want to do it properly regarding engine machining, etc. Most will advise it's not worth it for a 2.8, go to a 3.1 or 3.4 instead before dropping a lot of money in to a 2.8.
 

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Discussion Starter · #3 ·
I'm rebuilding because the motor sat too long, and the rings are stuck. I'm getting low pressures in all but one cylinder, and pressures below what is needed to even fire in 3 of them (1, 2, 3). Number 6 is the only one getting what I would call normal (about 155), while 4 and 5 are at about 130 to 135. One of two things has happened: Either the head gaskets were blown when I got it, or it sat so long the rings stuck and won't come loose. I soaked it with MMO last night and tested today, and will soak it again tonight with pure carb cleaner, and test again tomorrow, hoping for a change. If the pressures stay the same, I'm pulling the heads and checking for blown head gaskets. If the head gaskets aren't blown and the cylinders and pistons look good, then I'm taking it out completely and putting new rings and bearings in it. I can get those parts for only a little over $100, and of course I'll be doing the work myself. If the cylinders show a ridge at all, I'll consider my options at that point. I'd like some higher compression pistons for it, but as you say...it's not really worth putting a bunch of money into. I'm not going to spend a fortune on a truck that's probably worth less than $1500 when running, anyway. The body isn't bad, but it needs a grill, and the paint looks like crap. And I'm not going to buy a motor from a salvage yard for $600....I'll either get it running with this one, or wait until I run onto a cheap alternative, or part it out and crush it.
 

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a 3.1 out of a 91-'92 rodeo will bolt right in and I've bout 2 of them in the lsat year for $200 and $250. Also the 3.1 from the lumina van with TBI is a bolt in as well. Plenty of motors out there, way less hassle than rebuilding it.
 

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Discussion Starter · #5 ·
I haven't run onto one, or I would've happily spent two or two and a half. I bought this 2.8 several years ago with the intention of putting it into the 85 trooper, but never got 'round to it. Ended up with this isuzu pickup a couple of years ago.

Just recently decided I was sick and tired of seeing over a dozen vehicles in my yard/drive/field and only half of them running, and so here I am. What I don't have running or sold at beginning of March, gets crushed.
 

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We're not that far apart. I've got a 3.1 that I bought, removed the heads, started messing with trying to lap the valves, then determined it would be best just to have a machine shop grind the valves. I bought a complete engine gasket kit for it as well. I'd be willing to sell you everything for $350. You'd need to run the heads to the machine shop for a valve job, but other than that It's ready to go. We could meet in Bella Vista AR. Just let me know. Thanks
 
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