ok so when i go to turn the car over... the engine just turns over, but i have spark an i know i have fuel.. cause when i let of the key fuel shoots out some where in the throthle body......? it acts as if it wants to start but it just wont fire. me an a couple guys we think it's has to do with the timing (ign) the cam timing should still be fine cause we never mest with that part of the block.. but i buddy i know said that the orginal 305 ecu (ecm) wont start the 350.. i thought that the 305 ecm would atleast start the 350. I did how ever order the 350 tbi ecu today but it wont be here till tomarow after noon some time..... any idea?

91 camaro rs 305 tbi switch to a 350 tbi.

 

You probably ought to wait untill the computer comes in, but in the meantime, GM firing order is always 1-8-4-3-6-5-7-2, and the number one should be right by the left mounting bolt for the distributor, if I remember correctly. You might also check the possition of the distributor. If I can find a pic, I'll post it on here.

 

well we are pretty sure we got the firing order an the dizzy in the right spot.... the problem i had was not the firing order but were the number 1 spark plug on the dizzy was... but i think we got it figured out..... i think? but it turns over an sounds like its going to fire but i wont... then when you let off the key fuel shoots out......?

 

Are the injectors spraying while you try to start it?

 

ya the injectors are spraying an the theres spark.........?

 

Do you have compression? You should get about 125 to 150 psi on a comression test on each cylinder, if you have access to a gauge...

 

why wouldn't there be compresion....? all the gaskets are new. but no we havent try'd that didn't think that would be the problem.

 

If a valve isn't seating right, or if the rings are bad, or valve timing is off. I know you said you didn't touch the valve train, but was the motor running when you got it?

 

no we didnt take the cam or the valves out but we did take the lifters of an the push rods off to have the heads milled

 

How far were they milled? It's possible if you went too far, the valves may have bent on the exhaust stroke. I'm not exactly sure what the tollerances are on that motor for milling and valve clearance, but I've seen interference engines where the timing belt ratcheted and caused well over $2000 worth of damage in parts and labor over not changing a timing belt. Fun stuff. I would run a compression check if it won't start with the new computer, and if you aren't getting at least 100 PSI out of 3 complete cycles of the engine, and you can hear them quite clearly if you have all the spark plugs out, I would pull a head and check for valve damage.