View Full Version : Engine races on cold start intermittently
Mannydog
05-06-2018, 01:41 PM
Had my ZHP for 2 weeks. It has 103k.
So far, I’ve had 3 occurrences of the engine instantly going to what feels like full throttle when starting it the first time that day.
The first time I shut it down right away and restarted and it was fine.
The last two times the third try was the charm.
Otherwise, I seems to drive very well and idles smoothly.
I’ve gotten P0171, 0177 and 2227 codes.
Any thoughts?
Initial searching hasn’t yielded much so far.
Oli77
05-06-2018, 02:56 PM
Should you clean your ICV (Iddle Control Valve)? pretty easy try.
Cleaned the MAF?
PetesZ
05-09-2018, 09:55 AM
here is a ICV for dummies thread
http://www.bimmerfest.com/forums/showthread.php?t=248979
Mannydog
05-09-2018, 10:08 AM
I believe I did that a few years ago on my Xi. Most things I see about ICVs are about rough idle, which I don't have.
It's mostly fine, except for the 3 occasions it's revved super high immediately on startup.
Can super high revving be an ICV thing also?
Oli77
05-09-2018, 01:01 PM
You are right that ICV is after all, more of an idler speed controller. But your codes are saying lean on bank 1.
Could you then have a vaccum leak? The lower and upper intake boots are notorious for cracking. They are pretty cheap and could help with at least one of those codes. Same code is also pointing to MAF.
Could unplug the MAF and start her up. If the same problem exists that means perhaps your MAF needs at least a good cleaning.
I haven't the other 2 codes you listed.
Newjack
05-09-2018, 01:48 PM
+1 to what Oli said. Lean codes are usually due to a vacuum leak somewhere. Easy to diagnose if you take apart the upper and lower intake boots and look for cracks. They are prone to cracking quickly from the high heat.
MAF could use some cleaning as well. Maybe the previous owner ran an oiled filter at some point which could cause some hiccups.
When you say the car revs really high, how high exactly? Like foot to the floor RPMs bounce off the limiter?
Mannydog
05-09-2018, 04:42 PM
+1 to what Oli said. Lean codes are usually due to a vacuum leak somewhere. Easy to diagnose if you take apart the upper and lower intake boots and look for cracks. They are prone to cracking quickly from the high heat.
MAF could use some cleaning as well. Maybe the previous owner ran an oiled filter at some point which could cause some hiccups.
When you say the car revs really high, how high exactly? Like foot to the floor RPMs bounce off the limiter?
Yeah, I need to get in and look at the hoses and MAF etc. Should have time this weekend.
And the SES/codes are intermittent. I could see maybe if maybe more aggressive driving a couple or three times put a momentary stress on a boot or hose, that would explain it.
No sense of whether the hi revving starts followed a drive that tripped the SES.
As for the racing, yes, 100% like foot to the floor. Not sure how high it's gotten. Every time its happened I've switched it off as soon as I could react - pretty fast since my hand didn't even leave the key.
Powered by vBulletin® Version 4.2.2 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.