I did a v6-v8 swap(carb'd) on an 84 firebird and i got it running but it wont idle it will only stay running if i keep revving it. i searched and searched couldn't find an answer
and seeing everyone is so helpful i thought i would ask lol it fires every time just won't run for more then a second without me giving it gas.

Thanks
-Josh

 

You need to provide more details about what you put in.

 

i put a 350 .20 over with a steel crank 416 heads edlebrock performer intake hei distributor with advance curve and there was a 750 qudra-jet carb and put just a regualr qudra-jet..dont know the size but it fires as long as i keep giving it gas it will run but other then that it wont stay running the engine i put in has been completely rebuilt still had the lube in it lol

 

Where is the timing set?

Do you know if the carb idled on a different engine?

 

i have the vacum advance pointing towards the drivers side strut tower(i've had it all the way around and this is where it seems to start everytime) and im unsure if it did but the 750 i have did run on a 305 with juice runnin 13s at the track and it wouldnt even start with that carb.

 

Any gaping vacuum leaks I;E ports on the manifold or carburetor left unplugged?

 

where the egr valve goes on the on the intake has a strange block off plate with 2 tubes in it(never seen this before)
and the back of the carb where it connects to the brake booster doesnt have anything in it

 

I think we have the same problem, my cars RPM surges at idle and tries to die, sometimes it does unless I give it gas. Its just a 305 TBI. I think it may be fuel related and some people tell me a vacuum leak. When I start the car cold i have to either crank it and stop.. then crank it again and it will start, or just crank it the first time while pumping that gas. IDK if that has any relevance to my problem, anyway heres a video of my RPM gauge dunno if it will help or not but.. eh http://www.youtube.com/watch?v=8toyz91QCiA

 

did you say that happens when your AC is on if so unplug it drive it then start it with it unplugged my truck did the same thing your compressor is probably seizing putting strain on your engine causing it to die

 

You need to set the timing properly with a timing light. Until you do that, you can't blame the carb for anything.

 

i'll try that but i just ment the carb might be set completely different no? so i would have to play around with it

 

You're situation is extremely similar to what I experienced. I just dropped in a 355sbc, except my induction is TPI. For months I couldn't get it to idle for nothing. I must have set the timing about 50 times. I replaced ALL the sensors, no luck. As soon as I revved it or gave it gas, it purred beautifully. But once it got to around 1k rpm, it would shake like it was hunting for an idle, but would die instead. Finally one day I figured I'd try one more thing before I'd consider taking it to a mechanic. I assembled the engine myself and dropped it in myself, and I have never had any sort of formal auto mechanical education, so I figured this would be a learning experience as I went along. I was dubious about my valves, so I loosened them up half a turn, crank it again, and now it idles beautifully at 700rpm. Ofcourse, being TPI I have a roller (not solid) cam and lifters. The car is back to being my daily driver...

 

It will idle that like that regardless of the A/C being on, its just if i turn the AC on while its idleing it will most likely die faster

 

that makes sense ill give that a try