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So my '85 4+3 is having an issue at idle. When cold it idles fine. Once it warms up it will die at idle. As long as I keep my foot on the gas it will stay running, has power through the gears. I have replaced the IAC valve and the MAF. Also has a new fuel pump/filter, egr, plugs/wires, and injectors. Any ideas what the problem could be?
Last edited by PhilMyKraken; Dec 14, 2025 at 09:15 AM.
The coolant temperature sensor can cause issues with a warm engine. for me it caused a very rich situation that smoked and stumbled like crazy. After it cooled for 30 minutes or so, all was fine again. It might not be your problem, but it can cause warm engine issues.
Thank you I will look at the TPS. I just ran diagnostics on her and code 32 was the only one being thrown. That's for the EGR, which is brand new, done at a shop.
Code 32 could definitely be the problem.
There should be no EGR during idle, so if it is allowing exhaust gas in during idle, stalling is possible.
Here is some info from my 86, not sure what difference to 85.
C4 warm Idle issue
