My EFI CVH turbo engine idles high, Its chipped by MSD. I thought it was the ISCV, So I cleaned it out and re-fit it. It still happened, So I unplugged the coupler from the unit itself, It then decided to idle correctly.

Next step was to remove the Chip from the ECU, The Engine then Idled correctly, So I re-fit the Chip and it idled back up to 2500-3000RPM. Its off the road until Spring next year now. Any EFi gurus on here that can shed some light?

Ta in advance.

 

I've got the opposite problem on my saph. Had a stage 1 pts chip and ran fine. Fitted a stage 3
Msd chip and it hunts on idle. re
Fitted the pts chip and runs mint even on the greens and 3 bar map sensor. Can't afford to get it to Blackpool to have it mapped as thought like the pts chip u could set it up yourself :-(

 

If it idles fine with ISCV disconnected , then surely it is this at fault ???

 

Not really, because it idles fine connected with the chip removed. Its strange the car is fine with the chip removed, its only strange the car was fine as it was before I stored the car for 2 months on trickle charge. first drive afterwards, it idles fine.

Its also been stored with the battery disconnected for 24 hours too.

 

at the tag, dont go to MSD. The chip was fitted before i bought the car, and has been set up with it fitted

 

I assume this is Cosworth managed, if so check the TPS calibration.

Gcfcos, you should always get the fuelling checked, I suspect your CO is out.

Martin

 

Not cosworth managed just normal OFAB/OFAC EFi CVH H plate FRST.

 

Had it on the gas analyser at work and it's 1.5% co, sorry wrote overfueling by mistake it's my mates the other week that was overfueling lol :-( going mad in my old age!!

 

I would try 2.5 or 3 % on co mate just to see if that helps and gets rid of the hunting on idle

 

Got a replacement ISCV coming. Only cost £20.60 so worth a try.

 

I have an msd stg 3 cosworth that hunts also cheers will try that

 

Threads gone a proper u turn.

Anyone?

 

High idle could also be an air leak, certainly as you say it idles fine with the ICV unplugged (which it shouldn't, where is the air coming from to maintain the idle speed?), always good to check the simple things first mate as it may be a coincidence that it idles correctly without the chip.

 

My Efi cab 195 chip is the exact same there is loads of threads about it but I can't get to the bottom of it

 

Thats the 2nd person to mention air leak. Will have to remove boost hoses and vacuum pipes and check for holes. Its very strange for it to happen while being stored and not touched.

Carlo I replied on RSOC about yours, Is your chip MSD too?

 

I was told to unplug the idle control valve and re set the base idle and then plug it back in and let idle settle and then adjust the co. The bloody idle screws seized typical 4x4 saph problem. Strange how it idles fine on pts chip

 

Cleaned and fit the replacement ISCV, still the same. Let the engine warm up and still the same. unplugged the ISCV and then refit. Still the same. Removed the Chip and this time the idle still was high.

Each time I gave the engine a good rev and the idle would drop slowly.

So since last time, I reconnected the battery after having it disconnected in that time. Each trial was exact procedure as my first post.

 

Mark. Drive it the ecu needs to relearn idle and all sorts of other stuff. Esp after the battery is disconnected.

If it still high then look for a air leak esp where the vac pipes go into the inlet and breather.

Paul

 

I tried that a couple of months ago, remove the ISCV clean it and re-connect battery the day after. No change, I think i'll change all vacuum pipes including to the boost gauge(that one is plastic).

I do miss driving an RS and am tempted to re- tax and insure one, and the Fiesta may be it.

I did wonder if the TPS would cause the revs to drop slowly after revving it.

 

Anything is possible Mark. My efi cab idles a bit high too.