[dstrick32]

88 Chevy S10 2.8 V-6 TBI Auto

This truck was pulled out of storage or should I say it looked like a green truck but was a black one and I'm stuck with it. It was infested by squirrels and they had lunch with the wiring and vacuum lines. I replaced everything that I could see and it wouldn't fire up and run unless I used carb cleaner so i checked fuel pressure and ended up replacing fuel pump and draining tank while at it. Now the engine will fire up and runs fair until it starts to warm up and then it will start spitting back through the throttle body as if timing was out. Checked timing and set it but it continues to do the same. No check engine light at all and shows no codes since battery had been dead. Changed plugs, wires, cap and rotor got better but still spitting back through throttle body. Compression checked ok but haven't done a leak down test yet. Just wondering it anyone had any ideas, cause it sounds like a timing problem. Spark knocks like crazy it distributor is moved.

If it were mine I'd stick a V-8 in it and call it a day!!

[kev2]

long storage... the obvious and easy first: in case overlooked

bad fuel, did you do fuel filter, restricted exhaust - a vacuum test would help...
a cold eng runs rich...leans out as ect increases.... SO lets ck vac leaks, press reg im TB. could be rusted....also warm may permit EGR To operate* ..



*forgive me but 88 was a while ago I will ccheck that

[dstrick32]

Thanks Kev I'll run through them checks in the morning. Mean while I've changed the lifters and the stator & pick up in the distributor. Got it running fair but not in the ball park yet. The pressure regulator is a good guess cause the injectors are not spraying like I think they should. Also got a knock but sounds like it's in the top end. I'll have to do some checking on the valve lash adjustment cause Chilton's says 11/2 turns after the play is remove and Hayne's says 3/4 turn at which I set them since loose is better than tight. Got a whistle that sounds like a possible vacuum leak. Didn't have time to check it out cause I had to watch the NASCAR race and this job don't pay overtime!!

Thanks again!!

[dstrick32]

Pulled intrument panel to check the CEL but bulb was good, changed it anyway but still no CEL at start up or with ignition switch in on position. Fixing to check out the suggested problems. Running a lot better but still have the funky knock which seems to be in the top end and only after it warms up. Did some checking and it seems to be that the valve set at 1 1/2 turn after preset and timing at 10 degrees BTC with EST unplugged.

[ramntm]

I would suggest checking the fuel pressure.
Have you tried jumpering the aldl connector, to see if the cel will flash codes?
Also, is the knocking sound happening when accelerating or revving the engine? If so, check the egr valve to confirm whether it is opening.
Keep us posted.

By the way, How about 50 year old Mark Martin winning the race? Not only that, it was the first cup race Mark ever won in a car not owned by Jack Roush.... CONGRATS, MARK MARTIN!

[dstrick32]

ramntm the old man showed them a thing or two and he ain't dead yet!! I was really happy for him.
The CEL will not light under no circumstances, problem is nothing that I can see. Have checked fuel pressure and it's with in the 9 to 13psi range but will check again with TBI hooked up. Rechecked everything and the truck sounds and runs, just setting there haven't road tested it yet. The knock sounds like a rod knock but it just doesn't have the characteristics of a rod. only after the engine is hot an under accelaration. Just hasn't got the rhythm of a rod, far to rapid.

[dstrick32]

Well I went back and readjusted the valves to 1 1/2 turns and the dang thing still runs but the noise is far worse so unless somebody knows something I don't about these 2.8 engines, I'm fixing to throw in the towel. If it's something interal and I have to pull it out it dang sure ain't going back in.

Thanks everyone!!

[TECH II]

Some of these old vehicles, had a seperate module for the CE light....you would need a wiring diagram to verify this....

As for adjusting the valve lash, you need to adjust them when the valves are closed....this involves manually rotating the engine(the specific procedure allows you to do 3 cylinders at a time, and then after a totation, the other 3, anold manual will give you the specific procedure).....you loosen the rocker until you can manually rotate the push rod in your fingers, then tighten rocker until you can't......then do the recommended ammount of turn in the spec.....

I remember years ago, a tech did a head job on a 2.8 on a Fiero......just tightened the rocker arms down all at the same time....vehicle wouldn't even start because he had no compression.....found procedure in manual, and then it was ok....

[dstrick32]

TECH valve adjustment was done as you spoke of to get to the preset and then turned down as required. Chilton's said 1 1/2 turns after preset and Haynes said 3/4 turn. Tried the 3/4 turn first since it sounded more accurrate but still had a valve noise. Went back and tried the 1 1/2 turns and noise got worse. I've never adjusted the valves on a 2.8 before but 1 1/2 turns seem awful tight. I've adjusted many SBC's and I alway set them at 1/2 to 3/4 turns since I like them a little loose rather than tight. AS for the CEL I'll look ar the wiring diagram and see if I can tell anything. Really don't know what I'm looking for. Not an electronic whiz!! Thanks for the reply.

[ramntm]

Alldata shows a 20 amp ignition-gauge fuse in the fuse block. This fuse provides the 12 volts to the check engine light. The check engine light is controlled by the ECM.

[dstrick32]

Thanks ramntm I'll check it out. Right now I'm fixing to V8 this booger and pray that gas doesn't get much higher!! I'm gonna go with a stock 5.7 TBI coupled to a 700R4, so hoping for fair gas mileage