new problem,

car idles fine and revs fine when idling, but wont move forward without heavy choking and sputtering and trying to die.

i tried to check engine codes and it wont even flash.


I just put new headers and exhaust in last night and it has been doing this since i finished.
i have checked all my wires, and everything seems fine.
all the air pump lines and cat have been removed

 

u have a bad ecm

 

it was running fine before i added headers last night

 

I'll second iroctj.

I know it may sound far-fetched and illogical since you didn't do anything to the ECM. All I know is that when I rebuilt my engine, I didn't touch my ECM and when I dropped the engine back in, it did exactly what you're talking about. I kept thinking it was something mechanical--even pulled the heads, put them back on, and it did the same crap. Had a mechanic put a scanner on it and said he couldn't read anything off of the ECM. Popped in a new ECM, and it ran good as new.

It's worth at least checking--easy to do and could potentially save you a lot of time.

 

i have a 90 firebird 305 and ecm.

what other ecm can i use?
can i just swap the prom into one?

 

Zion is this a new problem?

did the ignition module fix the last problem?

 

yes

 

Well, it could be your TCC(torque converter clutch) solenoid going bad. That would cause the converter to lock up and chug when you put it into drive or park to the point where it will want to stall.
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Sorry, I just looked at your info and saw that you have a 5 speed. The info in my last post won't apply to you, sorry

 

haha no problem.


hopefully a new ECM will fix this

 

You still have the factory O2 sensors, correct? I know I had some issues when I put headers on my *gasp* 4th gen f body. The headers flowed so much more gas than the O2 sensors could read and it would stumble for a while. I had to keep disconnecting the battery to let the computer relearn the new values. Anyway, now I have a check engine light that comes and goes, and every time it is an O2 code. Instead of dropping a huge amount of cash on an ECM right off the bat, why not look into some O2 simulators unless of course you can find another coputer really cheap.

 

yes usually , if you don't even get a flash the ECM is bad.

 

well i replaced the ecm and same problem.

 

if the timing was way off, could that cause this problem?

 

if the timing was way off, could that cause this problem?

 

It could, My carbed car would have a really bouncy idle when it had lots of initial timing and when the a/f ratio was off.

 

but would the car not drive at all?


Also, my cousin took it out and around the block this morning after he unplugged and replugged in a bunch of sensors and the car ran fine for a good 2 min apparently. then went back to craping out...

 

anyone!??!


the car starts, revs around 3000rpm for like 30 seconds, and whlie it is up there it drives fine. then the idle levels out and gets kinda rough and it wont drive! just dies when i press the pedal!