Odd throttle issue, rough idle.

[Machgzus]

Today I started my 21 Mach 1 after about 10 days of very cold temps. Car is parked inside but the shop is not heated. When it started, it ran like it had a cam in it, zero throttle response in park. I shut it off and restarted several times and still did it, but it would rev in neutral and seemed to have throttle in reverse and drive. I let it warm up, still no response in park. Shut it off and when I restarted it again all was normal. No codes, no battery light, was showing 14 volts. Any ideas?

Sponsored

 

[John S]

Michigan winters get cold and we drive our Mustangs year round and we've never experienced throttle plate icing or other unusual weather related issues causing the engine to stumble or run "funny." Please keep us posted if you discover the cause.

 

[LCK22GT]

Condensation in fuel??

 

[Machgzus]

It's a fresh tank of 93, don't run E85 in winter. I'm thinking it was vvt related but not sure, once it was up to temp and restarted it didn't do it again. I went out first thing this morning, it was 14 degrees out, and started it with no issues.

 

[Charlemagne]

It happened to me once in 2022/2023 winter. Sounded horrible. Shut it off, then on again and all work. It was after a night of freezing around 15 °F and after weeks of not driving. Not once since but I don't really go out much in the winter. Thought maybe I should have pressed the starting button for longer.

 

[Schnder95]

My Roush does that also, when it has sat for a period of time when its cold. Its not a issue with the engine. Its to prevent the engine from any damage. Let it run like that until it comes up to temp. My car the RPMs jump up and down like it has a governor on it. it take mine about 20-30 mins to come up to temp that way. After that I shut it off and restart. Idle is back to normal. I was told its a engine safety measure.

 

[Machgzus]

Yeah i talked to a Ford master tech today. He said it was most likely a cold engine fail safe to keep engine rpm low. Also said sometimes low battery voltage can cause it but that usually would give a battery light. Thanks for the input everyone!

 

[Eyesac]

Every day I learn something...

 

[Nickel]

My Roush does that also, when it has sat for a period of time when its cold. Its not a issue with the engine. Its to prevent the engine from any damage. Let it run like that until it comes up to temp. My car the RPMs jump up and down like it has a governor on it. it take mine about 20-30 mins to come up to temp that way. After that I shut it off and restart. Idle is back to normal. I was told its a engine safety measure.

That's not normal...

 

[Unas2k5]

I live in Michigan and I’ve started my car after it sat with E85 in it in below zero freezing temps. This has never happened to me EVER. It should definitely not have any starting issues with 93. Never ever happened to me and I’ve had Mustangs since 2009 in the freezing cold lol.

 

[Machgzus]

Hasn't done it since and it's been plenty cold still.

Sponsored