stumped...92 rs camaro

[666_shooter]

ok...i have a 92 rs camaro...it came with a 305 but the people who owned it before me dropped a 350 in it but i dont know what the engine came from. the problem im having is...one night i parked the car and everything was fine and when i went to start it the next day it wouldnt start.

it started out just making a loud clicking noise when i would turn the key over so i thought maybe i had a bad starter...i went back a few hours later and the car would crank but it was cranking really slow so we replaced the battery and it cranks fine and the starter works perfectly...but now the car just cranks and doesnt seem like its getting any gas. first i checked the fuel pump and its fine...i changed the fuel filter and that didnt help so we tore apart the throttle body to see if it was actually getting gas and it was doing fine. the next thing we did was pulled out the #1 spark plug to see how it looked....i tried starting the car without the first plug in and the car started instantly..so we turned it off, put the plug and wires back on, and the car started right back up with no problems...when it was running you could feel some moisture in the exhaust but when i took the car out for a drive it ran perfectly without any problems what so ever so i thought that had fixed it and that it had just been flooded from all that cranking...when i parked it after that trip and went back out to start it later its doing the exact same thing it had been...just cranking and sounding like its not getting any gas...we changed all the plugs and wires and it started that first time then wont start any more...we checked all the fluids and none of them are mixing...no metal in the oil...etc.....after all this work and im still stumped and everyone i talked to is too.....could anyone please give me an idea of where i need to look next.......any help would be great! than you guys so much!!!

[Hypsi87]

hmmm I wonder if you are running so rich that you fouling out your plugs. if that is the case be careful of cylender washdown

[89IROC&RS]

sounds like a fried ICM (ignition control module) or HEI module. do you have a check engine light when its running? its definately a spark problem. you also might have a screwed up coil, but the modules are more likely i think.

[666_shooter]

its not running too rich i dont think...and when i took the plugs out they were all good so i dont think that that was the problem...THINK is the key word...and yes i have a check engine light on but it stays on because of the new motor, it never goes off unfortunately...so i guess the ICM is my next thing to try....god i miss that car and btw thank you guys so much for the help!

[Genopsyde]

maybe that's your problem, you have a 350 in there but the computer is for a 305.

[89IROC&RS]

thats very possible. even with the swap, you shouldnt have a check engine light on. an easy fix is to go out and get the chip from a 350 equipped car for TPI and the chip from a 350 equipped truck for TBI. this is something most people take care of, but hey, they might not have. but still, i dont think it would cause a no start problem, just run like crap. but its a possiblity.

[4onFloor]

I'm with Iroc, i think it's a spark problem. you didn't have to tear apart the throttle body to find out if it's got gas, just take the air cleaner off and watch the injectors while someone turns the engine over, you'll be able to see if gas is coming out or not. as for the ecm, it doesn't know the difference between a 305 and a 350, so i highly doubt that's the problem. i'd check the coil. grab the coil and and wiggle it around while someone turns the engine over, and see if it starts or tries to start. make sure you use a rag or a glove. i've seen problems similar to this, the car will start one time, and wont the next. the vibration of the engine tends to brake loose the primary coil winding from the secondary windings. i've never heard of many problems with the ecm on camaro's, only problems with them on early tbi suburbans.

[89IROC&RS]

i agree with ya 4onfloor, cept that there are differences in a 305 and 350 ECM, well the chip anyway. the PROM has specifications for airflow, fuel flow, what it expects to have drawn from it and what it is actualy putting out. a 305 chip is different from a 350 chip, but i still think its an ignition problem.

[666_shooter]

ok where im at so far...iono if its the computer but i know in the past i could turn the key over and all it would do was click and i would have to turn it back off and try again and sometimes it would take 2 or 3 times before itd crank but it would start fine....and earlier we checked the coil and its getting no fire what so ever...we took it loose and it made no difference from when it was on....so hopefully thats the problem...and the people who owned the car before me...i doubt they did a whole lot of the stuff they should have when swapping motors.......but i guess next is changing that coil...THANKS!!!!

[89IROC&RS]

hmmm, with those symptoms could also be a VATS problem. something to watch out for.

[4onFloor]

i'm not real sure to think of your check engine light deal. i've done a 305 to a 350 swap in a tbi camaro, and used the 305 ecm. the only time the ses has come on is when there was a problem with the O2 sensor, and a problem with the egr. as long as you have all the original sensors, the ses light should not come on. 350 and 305 use the exact same sensors and cfm throttle body. the ecm DOES NOT know the difference between a 350 and a 305. yes, a 350 has more cubic inch, and the maf sensor does get an abnormal reading of air flow compared to a 305, but the ecm adjust's for it. yes there is a difference between a 305 and 350 prom, but that's probly because the 350 prom was used in trucks and other cars equipped with a 350tbi motor. the camaro was built for optimum power and performance over standard cars, and the prom was probly programmed with optimum power curve, fuel flow etc. the camaro didn't come with a 350 tbi motor, there for there's not 350 prom in a camaro.

[89IROC&RS]

lol, the ECM does not know the difference, the PROM does, as you agree with, but the PROM tells the ECM what to think the MAF sensor will adapt to the increased airflow, but it will be running your fuel counts way high, which can cause problems, because it will be richening the mix to account for the increased airflow, and apparent lean condition. the camaro didnt get any special treatment as far as the program vs the trucks. its the same, gm went for the best average curve for power, economy, torque curve, and such. your swap may have run with the 305 prom, but its better to put the 350 prom in it. if the chips were the same, there would only be one chip. instead of the two different ones. GM is cheap, if they could have saved the money and only made one chip to do both jobs they would have.

[666_shooter]

ok guys thank you all for all your help....with class starting back i guess im gonna have to turn it over to the professionals TY ALL!