85 TA H.O. issues once car reaches temp - Third Generation F-Body Message Boards

rhalpin20 · 01-09-2009, 03:41 PM

I just finished reading the thread "Major issues any suggestions? " and i'm not sure if it is the same issue as i am having. I inherited an 85 TA H.O. CA emissions that had every emissions control removed. The car ran fine, but i have since been trying to make the car smogable and have installed all of the controls and now when the car reaches temp it dies. Among the components installed is a new Rochester 4bbl.. Anyone have any suggestions as to where to start?

naf · 01-09-2009, 04:12 PM

Does it die after it comes off high idle to normal idle or as the choke opens?

Your choke should be opening completely within several minutes. Once open it will allow the idle speed to drop to the curb idle setting. Is it that the curb idle setting is too low or that the engine won't run at all with the choke open?

rhalpin20 · 01-09-2009, 05:20 PM

Thanks for the response. Unfortuantely this is my first carbed car so i am kinda learning on the fly. I will have to investigate further but once the car goes to low idle it then dies and basically cannot be restarted until the car is cool again. I can start it with the accelerator pushed to the floor and as soon as it starts and i take my foot off of the gas it dies. Boy does it sound great until it gets warm though

naf · 01-09-2009, 05:39 PM

By the way, welcome to TGO.

Have you replaced all the common wear electrical parts? Plugs, wires, cap and rotor? Timing set correctly?

Choke open completely, blade 90 degrees straight up when it's warm? You should be able to 'almost' see it opening while the motor's running after it's initially started cold.

Curb idle speed adjusted to 'about' 600 rpms? After you've confirmed all of the above, try screwing in the curb idle adjustment (under throttle, driver's side) enough to keep it running when warm. Can you get it to keep idling at a reasonable speed?

I'd next look for vacuum leaks. I like to cap every plug on the carb and manifold, get the motor running then reconnect them one at a time.
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Bored at work: When you swapped an 84 engine harness into your 85 pontiac did you also swap over the 84 ECM? They'll likely have different pin-outs and at least the knock sensor circuit should be missing from the 84, unless it's from an HO?