RedRumCosworth

First off im new to passion ford so hi to everyone, i could really use some help. I have just purchased my first sapphire cosworth which needs a bit of work, mostly bodywork but im going to get it all sorted and resprayed, so if anyone knows a good reasonably priced painter in essex let me know. I want to get the engine running spot on first though.
The problem i've got is when you start it from cooled the tickover hunts between 500rpm/2000rpm until its warm up and then its fine for a bit but then it starts again. Has anyone got any ideas what the problem is? Could it be the idle control valve or a blocked breather. There is a link to a video below of the car running so you can hear the problem. Any help is much appreciated.

Thanks

http://www.youtube.com/watch?v=9rgLwoKLpvQ

RSLUBBY

iTrader: (19)

id say idle contol valve un plug the loom off the top if that stops it thats your problem take it off and clean they stick fella

CosworthGuy

Could very well be the iscv or an air leak of some sort. If no look maybe get it to a tuner nearby and get them to have a propper look. Oddkid is in essex i think. Knows a lot about rs turbo's but im sure could help with acossie too

RedRumCosworth

Thanks for your replys, i'll have a look at the icv and air leaks tomorrow and update the thread. Hopfully its something simple but if not i'll take it for a tune.

martysmartie

iTrader: (1)

Hi and welcome,

Ive had the same problem for the last 4+ years, mine is the valve.

However in your case it seems as if may it's just the base idle that needs setting correctly, I doubt this is an air leak.

The ISCV can only RAISE above this when needbe.

What is happening, is it sounds as if it's too low (People don't know how to set then up correctly which is what causes the issue) and so the idle drops too low so the ISCV brings the revs up until they drop again and so the process continues.

What you need to do is, is get to running temperature and with all electrical equipment switched off unplug the ISCV, I suspect at the point of doing so it will idle very slowly or die.

To adjust the base idle you will find a screw on the front of the throttle body, you first need to undo the locknut.

Turning clockwise will REDUCE the idle and undoing and so anti clockwise will INCREASE the idle speed, you want around 850-900 RPM.

Once you have done so reconnect the ISCV at which point the revs should rise slightly and then drop to normal.

Ps make sure you do the locknut up again properly else it will fall off and replacements are both scarce and expensive.

On another note it's worth assessing the power at the fuel pump and whether your cooling fans work, both are chronic weak points on these and will need rewiring.

Also if you don't know the history of them replace both the cambelt and fuel filter.

Martin

siscossie

iTrader: (4)

As above mine was the same it turned out to be the iscv and the co was way out, had it set up and all was well.

RedRumCosworth

Thank for the replys im gonna on tuesday. Is there anyway i take the iscv out and clean it, if so how do i do it and what do i need?

martysmartie

iTrader: (1)

Yes, you just disconnect the electrical plug, unscrew the 2 screws, remove the ring and then the valve will remove (They can be tight though!)

Usually soaking it brake fluid or petrol and then lubeing with light oil (Not WD40!)

Like I say, do what I said above first as it may not be a ISCV issue!

Martin

RedRumCosworth

i have just reset the iscv and it's sorted the problem, thanks

matcossy

reset?? how

TOMMY_TURBO

Mine does exact same as this since fitting a new chip

costina

iTrader: (1)

Base idle and co needs to be set correctly also fuel pressure needs to be checked.

steven8489

I agree with the previous posts regarding the iscv but it may also be worth checking the inlet plenum gasket as that was the cause of the problem with my last cos worth idle. Good luck

costina

iTrader: (1)

correct a high idle which cannot be adjusted will no doubt be some sort of air leak or failed gasket. I have seen them blown from the inlet manifold to head.