4.9L trouble starting engine after rebuild

[blair15951]

I have a 1992 seville

I recently stripped the engine down, replaced all gaskets and seals and put it back together but now im having trouble starting it.

when i try to start it, it turns over for a second, sputters, then stalls

if i move the timing up, it revs to 3500 rpm and stays there.. even with the butterfly valves closed... i can slowly push on the accelerator and it will redline but if i push it hard the revs die down and then it stalls....

after each attempt, i have to turn the key back and forth so it primes and then it will do the same thing if i try to start it again

any ideas?

[Bruce Nunnally]

Sounds like a great project so far. I do have the paper version of the 1992 STS shop manual, which has the 4.9L engine specifics, but I don't have an electronic version I can link.

First, are you putting the 4.9L into 'timing mode' before you set the timing? You have to jumper pins A&B in the ALDL connector while not in diagnostic display. The "SET TIMING MODE" message will be displayed on the Climate Control driver information center. Base timing should be 10 degrees BTDC at any speed less than 800 rpm.