One last try

[thunder57]

Recap:
I swapped a motor and trans from a 1991 S-10 with a 4 speed auto (4.3L) into an '88 full size truck with a 4.3 3 speed after the engine decided to die. Since then the engine hasn't been running right, it idles realy rough when it's warm and almost dies. The oil pressure drops right down, and the Check Gauges Light comes on. When I push the peddle right down, it will accelerate and then bog down, after a few seconds it will slowly pick up, don't know if that's tranny related or not.

I've checked the fuel presssure - 11 PSI
New O2 sensor
A different TBI from an S-10
Did a complete tune up
I tried two different EGR's and cleaned them both out

I took the truck to a local shop, they got $70 out of me, and they did nothing, they said they put it on the computer and there were no codes, and checked for vacuum leaks.

I'm sick of spending money... do you think it could be a computer related issue? I could get an ECM from an S-10, could be the PROM(what exactly is it, isn't it like the main chip) Could I just swap the ECM over into my truck... Where is it on the S-10's and Fullsize Trucks. Thanks for any help. I love my truck and want to do what I can to make it right again.

[1993blazerlt]

what parts did you keep on the engine from the s-10? How did you deal with the lock up on the tranny?

[nomaboy]

was the engine running right before it came out of the s-10? cause with the oil pressure dropping and the engine idleing rough when it gets warm makes me think the engine is just toast.

[thunder57]

I didn't keep any parts from the original S-10, well the starter, alt and stuff, everything else I kept from the other truck and put onto the engine. Where is the location of the oil pressure sensor on the S-10's engines? I had to swap the oil pressure sensor from the other truck because there wasn't one in the same spot from the S-10 motor, and the oil pressure was low on the original engine but that engine was toast. When I first got the engine I did a compression test, 160 on every cylender, and it never ran like the same after the swap. Well when I put the tranny into the truck the wires were already there, I just pluged everything in and it all fit. I can take pictures if you think it will help.

[bvr775]

the s-10 had a 190 or 165 hp engine(depending on vin) the full size has a 210 hp engine. there were differnces in the engines. I belive at one point they had and odd fire in one and an everfire in the outher so check this.
But I know the Intake manifolds and gaskets for a carbed and tbi engine or differnt. I ran across this a while back. You'll have to use an aftermarkt intake for it to work. Sounds like your intake gasket is leaking for. Swap over to a carb if you haven't allready.
did you rebuild the engine you swaped into the truck are just drop in a junck yard engine? A master rebuild kit is only around 300bux vs the time and damage a bad gasket, gunky crap in the cranck case, or slightly worn bering will cause.

[thunder57]

The original engine in the full size was a TBI, and the only reason I put a S-10 TBI on it is because I sold the original one and someone screwed up the TBI which was on the original engine. I found an S-10 on the interenet for $350 the guy was going to put a 350 in it but changed his mind, the engine ran realy well when I drove it home. I did not do any modifications to the engine except an oil change and tune up. What is included on a master rebuild kit?

[bvr775]

In that case get with matt4.3 I thinck he had to have something done to his comp to get his to run right.

it'll have all your gaskets, freeze plugs, crank and rod beirngs, rings, basicaly every thing you need to rebbuild an engine except tools.

you will have to pull the pan and check your bering before you order the kit and mic the crank, cranck journels and rod journels, because I've pulled apart a few factory engines that had .10 over berings enstead of the std berings. I like orileys kit. It's seems to more complete and it's better quality than some I've used. Napa also make a good kit, but it's kinda pricy for what you get.