QuestionHello, here is what I have. 1978 Pontiac Trans Am with a 400 engine bored.060 over, headers, alluminum intake, Magnum 270 hdy cam Quadrajet carb, 350TH transmission.Nothing radical just a simple upgrade above stock.
The problem I am having is trying to adjust the carb. Following all steps with a vacuum guage, setting curb idle all the regular stuff, but when i put it in gear it wants to stall sometimes and even goes dead. I basically have to drive it with two (2) feet.
I have had the carb kit built by a well known carb specialist known to Trans Am Country to all the specs I stated. Also have had the carb rebuilt by a very reputable shop here in MS. where i'm from.
I am so frustrated and don't know which way to turn. The season for riding is here and I am stuck,
Any suggestions
Robert
AnswerI checked the factory specs on this cam. Magnum claims that this is the most high performance cam that you can use with a stock torque converter. It also says that this cam in a small block will give a rough idle. This tells me that there is a lot of valve overlap between exhaust close and intake open. This gives the rough idle and rough low speed. This tells me that you are chasing your tail trying to solve the problem via the carburetor. You might have to replace the torque converter with a high stall speed performance one or just live with a higher than normal idle.
