When starting car from cold for approx 5 mins the car idles very eracticly the revs go up and down between 500 rpm to 2000 rpm.I have changed the idel speed control valve for a new one and put new plugs in hoping this will sort the issue but since i changed it i would say its been worse also when driving have found engines not running smooth at all only when cold when warms up all seem fine.

What sort of things should i look for? ive changed isv and plugs what next should i go for rotor arm,cap and leads?

any help would be great!

 

I have the same problem with mine, disconnected ISCV, the fact that the idle is able to raise revs and drop shows it to be working, rather it is being told to do this. I often thought it could be my CTS causing problems but car otherwise runs perfectly fine so not to fussed about it.

I would check CTS and TPS, won't be air leak otherwise it would happen all the time. What chip do you have?

Martin

 

Check your CO when hot is to what the chip maker says, it sounds like a mixture problem, as in too lean, this could be caused by your cts, don't just go replacing bits it's false economy and not needed the cossie is very very basic engine wise.
tabetha

 

i always thought it was the actuator on the turb bouncing in and out

 

mine rises and falls aswell from cold,i got told it was normal and shows its working.

 

i would say the same as tabetha gaz, check the co.

 

base idle to low

unplug the iscv and set the base idle to 900 with the engine hot.

if the ECT sensor is working then it wont be mixture related imo, any cossie reading from the cold start mulipiler table will be rich, and as the problem cures itself when its warm, i cant see it will be mixture related at all as that will be its leanist point.

 

Hunting is in no way normal and should not happen, the valves stick sometimes but this is due to valve if yours hunts something is making valve operate. I will sort mine out just never really been bothered as run without ISCV at moment and otherwise runs fine.

I do notice on mine that it's fine once started, it was only when I tapped throttle hunting would start hence me saying check TPS output.

The actuator does not effect idle at all and does not "bounce" in and out.

Martin

 

Was the new ISCV brand new, or another second hand one?

If second hand, take it to bits and clean it properly

 

got a similar thing with mine, with the iscv connected the revs go up quite high to somethign like 2k and sticks when its cold, not tried it when its warmed up recently as ive kept the ISCV disconnected but could it be the ECT sensor causing that too?! i cleaned it all out ages ago so its not gunked up, car once warmed up for 5mins with the ISCV disconnected runs fine other than a hesitation but thats being put down to the map on the chip on the car being from before the head was ported and needing a re-map!

 

My Sapp did this for a while; it was a faulty fuel regulator.

 

thanks for the input guys gives me something to work on.Ive got new rotor arm,cap and leads to put on so will crack on with that over weekend hopefully and see if that improves things! If not them will look into the other possiblities mentioned,just want to enjoy the car as at the mo i aint seems to be running like a sack of shit

 

If the co is lean when hot, then consequently it will be leaner than intended when cold, this will cause issues as you have.
Mine starts 100% perfect and drives 100% perfect from cold within 1 second, can't even tell it's idling without looking at tacho, my iscv sometimes works mostly not, not worried though, still idles perfect when old, but then I'm not on L6.
A cold engine is vastly more arsey/sensitive when running of mixture differences.
Either get a full mapping job done or accept it's never going to be 100% of what it could be, otherwise there would be no point in mapping if there was no gain to be had from doings so, can make a world of difference even on std engines.
tabetha

 

Had the Same with mine, and in the end it was the
icsv.

Edit: cleaning hasnt solved the problem, had
to buy a new one.

 

Our L6 software will cold start and drive perfectly when cold, its nothing at all to do with the ecus ability to add fuel and increse idle when its cold.

lean on cold start lol. id be amazed if you find a cossie cold start at less than 6% co even if the global mod is -30, and it certainly wont lean hunt at that. and the fact remains it doesnt hunt when its warm, so it cant be that lean lol.

 

Be interesting to see who's got it right, its getting abit bitchy in here

 

its also a very bad idea to adjust the global mod without checking fuelling under full load on a dyno or with a wideband afterwards.

either way, the rpm should never reach 500 rpm, so the base idle is too low, and low base idle will also cause irratic cold start idle as the iscv can struggle to maintain a steady speed, as the iscv trys to close to reach its desired rpm, the revs drop to low, so the iscv opens again and so oo and so on.

i would clean the iscv with a thin oil, not wd40,make sure it returns perfectly to the shut position and is free in motion, and then warm the car up, unplug the iscv and reset the base idle to 900-950 via the screw under the throttle body.

my guess is the base idle will be to low, and when you unplug the iscv the revs will drop which they should not, the base idle should be held on the idle screw not the correction valve.

thats what i would do first, as thats the normal cause, and it takes 5 mins to do.

after that, i would be looking at checking the sensor operation, checking the tps calibration, and monitor fuelling.

 

well i know with mine i took it apart and cleaned it etc and setting the rpm to 900 but as soon as u plug it back on it revs to just shy of 2k rpm and doenst budge!!! any ideas james?! like i said earlier needs another chip to sort the hesitation out (spoke to julian godfreys about it as its their chip and it was for standard head not ported) but the idle thing is a pain in the arse as ive had to use it for work at the mo and i cant sit there holding the rpm from stalling it with the throttle as it annoys the neighbours

 

i need a new one of these, ive seen them on ebay as the same item as a mondy is that true

 

I know the ones on the bay there remanufactured not OEM if it's the Ł10 ones I have seen also noticed it lists it for Mondeo I'm 99.9% sure Mondeos did not use these, Fiats however did along with the rest of the EMS, OEM ones will be expensive.

Tony Knee, with yours it's not the valve at fault it's being told to open this much as to why it's doing it is very wrong especially in a hot engine. The fact when it's disconnected the revs drop show the valve to be WORKING. I would check TPS.

Martin

 

Think he means the ones that are up for Ł65!!

changed the tps for another and it didnt make a difference, was second hand but wouldnt expect to have the same prob with 2 of them!! checked it and they both seem to work ok with a multimeter. The ISCV wasnt as bad till i cleaned it out then it actually got worse after

 

sounds like a tps issue or calbration problem mate

 

calibration with what?! Guess i could get a new TPS and see what happens, but dont want to waste money on a new one if its not that.

Would the coolant temp sensor cause any problems btw? its an old one on the car. If i have to will let julian godfreys sort it out when they set it up but ideally want to minimise what i have to pay them to fix!!

 

Tony,

I have my old 2wd TPS if you want?

By calibration I assume James means the chip...

 

yea cheers might have to borrow it off u just to try a third one, althou have checked and adjusted both the ones i have going by the manual and checked the ohms values when pressing the pedal and all seems ok, hummm!!

 

As I say you need to check the TPS calibration. 2WD should be 5V no throttle and this should decrease to 0.6V or something at WOT. Vice versa the above figures if 4x4.

Martin

 

what pins do u use for the calibration/volt test, im guesing u remove the hairbrush off the ecu to do it?!

I did it on resistance test as per the manual not volt test using pins 30 and 17, was open circuit with no throttle, and within range and increase accordingly with pressing the throttle.