I bought a 84 Firebird s/e with a quadrajet. the car had last passed emissions in 2005 shortly there after the 2nd to last owner slid the car up over a median that took out the oil pan and the transmission, by the last owner checked the frame and certified to be good, the transmission was replace with a 700R4 from an 87 Camaro and the engine checked and pan replaced .

Since owning it I've changed the stock fuel pump, replaced the carb. with a new remanufactured quad from holly. also have replaced a ton of rotten vacuum line, and replaced the fuel line from the fuel pump to the carb. Ive also replace the coil, spark plugs(which were in good shape), and checked the plug wires. I've also put new skins an rims on the car as they were needed and a new factory style exhaust and O2 sensor. The shop that did the exhaust work used the old cat but said it appeared to be good.

I had tried to rebuild the original carb. and then opted for a new rebuild after the car dieing on it way to emissions(one of those panic buys that I'm not overly proud of).

the problem is that while under no load in front of the house the car will run very well, I've got it timed to 6* at about 550 rpm with the ECM disconnected. i can hold 3000 rpm pretty much indefinitely and other than a little bog(very minor)when gunning the motor every thing checks good and calibrated. Under load the car bogs and dies constantly. this dieing has included limping the car home several times, stopping traffic on highway 58 once due to dieing in a construction zone(learned there are a lot of rude people in the world on that trip). nothing I've done so far is seemly helping this one issue and its holding me up from emissions, I've also ran out of time on my third temp tag for the car.

I'm thinking that there may be silt in the gas tank thats clogging the filter due to the time it has sat but the fuel filter seems to be in good shape and ive went though three filters so far.

Any advice is very welcome as maybe theres something any thing ive missed, im not looking forward to pulling the tank as it just looks to be a huge pain coming my way lol. this car was to be a daily driver for my wife.

 

Welcome to the forum crackrat!
What carb is on it now? The holley reman?
Is it still a computer controlled carb? With the mixture control solenoid and throttle position sensor?

 

TY Sonix, yes I've been lurking for awhile and gathering info as i needed it but... whoot first post

the remanned holly quad is on it now, the old carb had similar symptoms though. And yes its the cc carb. TPS is currently .48 - .51 and and the MC is running at about 53-51 6cycle dwell hooked to the green trace cable by the a/c and ground.

at least the computer code reader is giving me just code twelve

 

Dwell should be 30 degrees on the 6 cyl scale - that's 50% duty cycle.

The ignition module is another known weak player on these cars. You could just replace it, or see if a store can test it for you.

 

LOL well late reply out of me.....Tuesday in the morning i was sitting in between the two mills i run when it dawned on me Vacuum!!!! i went home early to get ready for another attempt at making it thru emissions, double checked my vacuum hoses and realized when i had exchanged the carbs i had exchanged hoses wrong, very wrong. the emissions hoses were laden in gasoline. I blew out each hose as best i could and started the car and timed and tuned it and passed with just a hint of a high HC. Onward to getting the lights moving and a tranny leak from hades.

side note one of the neighbors that calls any time a car sits for more than 10 days was the individual that did the emissions. Call it desert to have him have to pass a car that he had called on a 2 months earlier when it was delivered by trailer.

@five7kid yes, TY for the clarification. it was set right, just typed wrong lol