E85 stalling issue - GUIDE for others

[jpvd]

Hi All...

Thought this might help a few people on here...

Long story short i had left my z4 e85 2.2 sat in the garage for a couple of years and finally decided to get her out, get an mot and back on the road....only to find that three coil springs had collapsed and all 4 shocks were knackered (that’s another story! - all fixed with a full set of coil overs)

i also had an issue on start up whereby the revs would bounce up and down, then settle when warmed up, but as soon as you touched the throttle the engine would have a massive flat spot and try to stall. On a drive it was fine at high revs, cruising on the motorway, but as soon as you came to a stop or tried to set off from lights it would try to stall...it was also guzzling fuel

• no engine light
  no fault codes
  checked spark plugs and cleaned
  checked coil packs
  maf was new two years ago
  disa valve was new two years ago
  burnt off the old fuel and ran with shell power and some injector cleaner

so i was kind of lost at this point.....then i came across some posts which mentioned the ICV (idle control valve) which i didn’t realise were on the e85. Decided it was worth a shot - so i removed the ICV and it was all full of carbon and stuck solid, so after lots of carb cleaner and rags i got it all freed off and like new. Put it all back together and the motor now runs absolutely perfect, with no bouncing revs or stalling or flat spots…

so I thought this might help others…. I followed this guide here on youtube >> [youtube]https://youtu.be/AgMFHaRhRdI?si=0ucr2uHlDfpZXw_l[/youtube]

Hopefully this might help someone and I would recommend everyone checks the valve during their next service as it is easy to get to and simple to clean, so well worth the effort….(note: excuse how dusty the engine looks - still needs a good clean up after being stored and taken over by spiders!)

 

[StudioWizard]

This is super helpful! My 2005 2.5i stalls out every once in a while randomly. I've owned the car a little over a year and it's happened 3 or 4 times including last night when I was backing up out of a parking spot. The car stalled and the engine stopped. I restarted it and then no problems after that.

I wonder if some engine cleaner additives would also do the trick to clean out gunk on the ICV?

 

[colb]

ICV is known for getting carboned up so it sticks causing idle issues, bouncing taco is a good indication it's sticking. Only remedy is to take it out and clean it using carb cleaner to wash it out. Once clean if you shake it in your hand it should rattle as the internals turn freely. High fuel consumption can be due to air leaks in the vacuum system check all rubber and plastic vacuum pipes for holes or splits. Unmetered air picked up by exhaust sensors that don't match what it saw go through the Maf sensor will fool the ECU into thinking it's running lean and demands more fuel at the injectors to richen it. Will add up to 20% more fuel till it realises it's not correcting it, mpg will decrease dramatically whilst air leaks remain. Viewing fuel trims in live data is also a good diagnostic giveaway that air leaks are responsible for high fuel trims.

 

[StudioWizard]

ICV is known for getting carboned up so it sticks causing idle issues, bouncing taco is a good indication it's sticking. Only remedy is to take it out and clean it using carb cleaner to wash it out. Once clean if you shake it in your hand it should rattle as the internals turn freely. High fuel consumption can be due to air leaks in the vacuum system check all rubber and plastic vacuum pipes for holes or splits. Unmetered air picked up by exhaust sensors that don't match what it saw go through the Maf sensor will fool the ECU into thinking it's running lean and demands more fuel at the injectors to richen it. Will add up to 20% more fuel till it realises it's not correcting it, mpg will decrease dramatically whilst air leaks remain. Viewing fuel trims in live data is also a good diagnostic giveaway that air leaks are responsible for high fuel trims.

Good info! Thank you!