National Firebird and Trans Am Club Message Board

Technical Areas => Engine Related Items => Topic started by: may2018 on May 04, 2018, 12:14:20 PM

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Title: '75 TA Missing and Backfiring
Post by: may2018 on May 04, 2018, 12:14:20 PM
So far you guys have been awesome when I have had issues on my Trans Am. Yet again another problem though. At idle and while trying to maintain the speed car is missing and backfiring. As long as you are giving it gas or flooring it, it runs great. It was driving perfectly normal then it died as I was coming to a stop and fired right back up but is doing this now. Only thing I had done that day was replace thermostat but put at least 50 miles on it before it did this. I have checked for vacuum leaks, changed plugs and wires, cleaned fuel filter. It still starts very easy even with how cold its been. Also right when you fire it up it sounds and runs normal for a few seconds before rough idle and miss kicks in and will only backfire out of passenger exhaust. My car is 1980 with a Pontiac 400 out of a 75 TA.
Austin Allen
Title: Re: '75 TA Missing and Backfiring
Post by: firebirdclub on May 04, 2018, 12:16:53 PM
I had a similar issue on my ‘74 back in the day. I found my carb gasket was shot and excess gas was pouring in at idle and it couldn’t handle it because there wasn’t enough air to atomize the mixture.
Thomas Casilllo

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