88 TBI 5.7 fresh rebuild running gremlins
 

Short block rebuild / install.

Motor will only start with gas pedal pushed, will not idle and sounds to be missing. Pulled and confirmed spark on all plugs. Engine ran before rebuild but was knocking.

What is making it run like this??

Also, when I pulled the plugs to check for spark, #7 didn't have any sign of burning. It still looked new, but sparks on the manifold. Hope this helps

Check ignition timing, pull SES codes and check cap/rotor for corrosion. I've heard of distributors on these SBC engines having worn out distributor bushings. Might look into replacing the distributor, but hold off on that option until we've explored other things.

Motor won't idle enough for me to get a light on it. To get me going, I got #1 to tdc and lined up #1 plug wire with rotor button but ended up having to turn dist. Counterclockwise about a half inch and advance the timing just to get it to where it would start. Cap, button, wires, and plugs are all new. Would probably lean away from dist. bushings being bad since it wasn't a issue before the rebuild.

What next ????

Loosen the distributor hold down and hold it steady. Have someone start the truck and keep it running as low in the RPM range as possible and turn the distributor to while watching your timing light. It sounds as if the distributor is either advanced or retarded to much. Another question was the cam degree against the crank or just slapped in there? Distributor bushings could be worn, or possibly the drive gear worn. Is the firing order correct?

Cam sprocket dot and crank sprocket dots aligned. Firingg order is 1-8-4-3-6-5-7-2; must have checked and rechecked @ least 100 times. Still leaning away from worn dist bushings as it operated properly before tear down.

Open to ALL suggestions; this is probably something stupid simple I'm overlooking. HELP !!!!!

your distributer could be in wrong
by that i mean it will go in the right way timmed then the other it will still fit down all the way but will be off a coulple dergrees
also check the rotor on the dizzy it may be off it may not be the cap
also check fuel pressure

You say it starts with the gas pedal pressed, which all that is doing is allowing more air into the engine. I would check the IAC valve since it's job is to do just that. It would also be the reason it won't idle once started.

New rotor is fully seated and dist shaft has no side to side play.

Loosened fuel line to throttle body and fuel squirts everywhere;so no pressure problem there.

Point me towards the IAC valve please Mr. S-rock

It screws into the throttle body on the passenger side and looks like this...

http://t2.gstatic.com/images?q=tbn:A...EtVc_9t51qQihj