350 tbi problem???

[1987 GMC Jimmy]

I hope more people chime in with what they'd do, but I might borrow a compression tester from Autozone to make sure each cylinder is on an even keel with the others when cold. It would rule out any fundamental mechanical problems. The vacuum when it warms looks good.

 

[JOHN MEADOWS]

I hope more people chime in with what they'd do, but I might borrow a compression tester from Autozone to make sure each cylinder is on an even keel with the others when cold. It would rule out any fundamental mechanical problems. The vacuum when it warms looks good.

I will check compression to see what they are at. This thing is aggravating me to death. Anyone else have any ideas ?

 

[JOHN MEADOWS]

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[4WDKC]

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did you test the compression?

 

[JOHN MEADOWS]

I haven't yet will do that soon. I have to barrow a compression gauge

 

[Rusty Nail]

What does compression have to do with surging idle besides.....nothing?

 

[1987 GMC Jimmy]

The compression test logic is that a steady lapse in vacuum might indicate some sort of problem on a cylinder. That’s really all I’ve got. I think many of the diagnostic tools for TBI have been presented throughout the thread.

 

[JOHN MEADOWS]

A friend of mine with exhaust shop is gonna fix my leak and while he has it there is has a scan machine he said he would hook and see what it shows. He will be doing that this Tuesday

 

[JOHN MEADOWS]

So got it back from shop they said tried to hook it up to computer and never could get it to sync with truck. They said they don't know why. He found a exhaust manifold leak and tried to tighten it best he could. Leaks seems better.

What would be reason computer won't sync to truck?

 

[4WDKC]

did they supply power to the connector at the truck?

 

[Rusty Nail]

Does the door buzzer work?

Yes or No

Remember readers about the five second fuel pump relay energizer circuit?

WHAT THE **** DOES THAT HAVE TO DO WITH THE DOOR BUZZER?

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[4WDKC]

Does the door buzzer work?

Yes or No

Remember about the five second fuel pump relay energizer circuit?

WHAT THE **** DOES THAT HAVE TO DO WITH THE DOOR BUZZER?

Lucky bastard, day drinking while the rest of us are working.

 

[1987 GMC Jimmy]

I know I have a 33 year old scan tool for CCC/early TBI, and it’ll give the error message when it can’t interface with the ECM because the diagnostic circuit is fried or the whole thing is fried, which has happened to me a bunch.

 

[JOHN MEADOWS]

did they supply power to the connector at the truck?

He just said when they plugged it up it wouldn't connect to truck

 

[JOHN MEADOWS]

I know I have a 33 year old scan tool for CCC/early TBI, and it’ll give the error message when it can’t interface with the ECM because the diagnostic circuit is fried or the whole thing is fried, which has happened to me a bunch.

If that was case how can I check codes with paperclip and it work?