Needing some help!

[Killovision]

I need some help pin-pointing this issue. The car is a 1980 Trans Am. I pulled out the 301 and installed a rebuilt olds 403 with performer rpm and 750cfm edelbrock carb. The carb was not new! All the emissions stuff has been done away with. Been running fine for the last Six months. Recently, it's began to idle REALLY rough after about ten to fifteen minutes of drive time. I'm thinking carb issues but I would like to know what you guys think before I go into that. Why would the car run fine for 10 to 15 min and then start crapping out. Also... today after that happened, i got in the gas and it began to stumble and backfire through the pipes. Any info is greatly appreciated! Thanks! Eric

[KaotiKCamaro5]

sounds like your fuel pump is on its way out to me..

[Killovision]

The fuel filter stays completly full at all times. Gettin great fuel flow.

[custom mccannix]

where is the fuel filter is it on the intake? if so you have to move it to the fener because it is vapor locking it. i have the same T/A but with the pontiac 400, and i had that problem. also your carb is to small for that engine you need at least a 800 cfm carb for it to run right otherwise your are drinking gas but not going anywhere. you also have to adjust carbs every weekend or so to keep them in tip top shape. they can last about 6 months without any adjustment but your performance will start to drop like a rock. also have you checked your igntion timing? that can cause some issues to. good luck and keep us informed

[Killovision]

Sorry it's taken so long to get back. I havn't had much time to do anything thanks to the day job and working on other peoples stuff. I've tinkered around with the timing. It's hard to get it perfect on this engine on count of the pointer location. The engine calls for 18* but the guide only goes to 12. Anyways, it ran great for a few months. I believe the timing is dan close though. I just bump the ignition and it fires up fast. I'm gonna take my buds carb and swap it over and see how it does tomorrow. Also. I got the filter set up about six inches from the carb inlet. Clean as can be. Thanks for the advice on that carb size! Guess i'm gonna have to come up with some bucks for a new edelbrock. Jeesh!

[custom mccannix]

no problem! Go to your local parts store and pick upi an after market pointer preferably with an adjusting slide that way you can move the pointer slide to 18* so you can see it with the light better. Also if it has an aftermarket cam the timing may need to be set higher or lower just play with it around 18 till she hits hard!

[Killovision]

Been a while since I posted. To anyone interested. Rebuilt the edelbrock. Car runs like a champ now. Had all kinds of crap in the bowls. Thanks for everyones input! E