Car revs up on start up?

[chuy_lll]

Hello all,

I understand when cold starting a car it will generally rev up to a higher rpm to warm up but recently my car has been reving up to about 3000 rpm both on cold and non cold starts is this normal? I also recently got codes for misfire in cylinder 1 as well as misfire on start up and was planning to change out the spark plugs again as I changed both spark plugs and coil packs about 2-3 months ago. Car is tuned on E85 47 lb injectors, 1 7/8 catted long tube headers, imrc locked 18+ ported mani, and a cai. Any advice/help would be appreciated TIA.

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[KeyLime]

Does the idle rpm return to normal after the engine warms up?

 

[KeyLime]

Does the idle rpm return to normal after the engine warms up?

My bad, I reread you post and this happens on non-cold starts too.

 

[NightmareMoon]

Hello all,

I understand when cold starting a car it will generally rev up to a higher rpm to warm up but recently my car has been reving up to about 3000 rpm both on cold and non cold starts is this normal? I also recently got codes for misfire in cylinder 1 as well as misfire on start up and was planning to change out the spark plugs again as I changed both spark plugs and coil packs about 2-3 months ago. Car is tuned on E85 47 lb injectors, 1 7/8 catted long tube headers, imrc locked 18+ ported mani, and a cai. Any advice/help would be appreciated TIA.

What CAI?

Have you talked to your tuner?

 

[chuy_lll]

What CAI?

Have you talked to your tuner?

JLT and no I haven’t as it’s something that started recently and they are closed on the weekends

 

[NightmareMoon]

Everything pass a good visual inspection?

 

[chuy_lll]

Everything pass a good visual inspection?

Yea as far as I can see

 

[NightmareMoon]

If it settles down to a normal idle in a few seconds and it runs right after that then the tune probably just needs a tweak around the startup open loop.

 

[chuy_lll]

If it settles down to a normal idle in a few seconds and it runs right after that then the tune probably just needs a tweak around the startup open loop.

I see going to contact them and let them know what it’s doing

 

[Pistol_91]

Did the car run fine after your coil and plug change? Has it been on this tune for awhile and been fine? Was the last batch of e85 good fuel? I'd check the plug and gapping on that cylinder to begin with. Maybe try changing the coil around to another cylinder to see if it could be the cause. The high idle is usually related to a vacuum leak or the tune but if the tune has been on your car awhile and now all of a sudden you're having issues, I doubt it's the tune.

 

[chuy_lll]

Did the car run fine after your coil and plug change? Has it been on this tune for awhile and been fine? Was the last batch of e85 good fuel? I'd check the plug and gapping on that cylinder to begin with. Maybe try changing the coil around to another cylinder to see if it could be the cause. The high idle is usually related to a vacuum leak or the tune but if the tune has been on your car awhile and now all of a sudden you're having issues, I doubt it's the tune.

Yea the car was running fine. I didn’t get to test the E85 last time I pumped since I was in a rush but the station I always get it from tends to be good. I see I’m going to try that hopefully later as I won’t have time during the week.

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