Hi, Not an unusual problem with cosworth’s I know but my 2wd sapphire won’t idle, So yesterday I decided to go out in it for the first time since the lockdown began, (I always start it up every week for about 10 mins, always starts first time and runs perfectly) as always it started and idled fine, after a few minutes I went for a drive for about half an hour, got back home, everything still all good, turned it off so I could go and open the garage door, got back in and turned it over, started up but cut straight out, tried again but using the throttle, fired right up, took my foot off the throttle and cut out again, so as long as I keep my foot on the pedal it doesn’t cut out,
this morning I thought I’d try starting from cold, still the same, wont idle, so just as a quick fix ( obviously I know it’s far from the solution) I’ve just adjusted the idle up on the throttle cable just to keep it running,
I’ve thoroughly checked that all pipes and wires are still connected, and they are, that I can see ,
so my question is what should my next step be, as always any help would be very much appreciated,
TIA

 

Seen tps mentioned throughout the years worth a try

 

I done a search on here and yes it could well be the problem, that’s definitely not something I’d be going near myself, I was hoping for a few ideas to try first, if all else fails then I’ll have to take it to someone who knows what they’re doing,
thanks for the help, appreciated

 

From the sounds of it, your ISCV is not operating. Apply power directly to it and see if it operates, you will have to setup the base idle again in any event, as you have adjusted it.

Martin

 

Bad TPS calibration usually results in a bad idle, it sounds like your valve is not operating.

Martin

 

Hi Martin, i was hoping you’d have an idea, you was spot on last time when my mk2 Escort was playing up,
Excuse my lack of electrical knowledge, when you say apply direct power do you mean remove it and Give it a live and earth feed?
prior to this problem, when I unplugged the valve the idle never changed, I was under the impression it should at least do something. Is that an indication that it’s faulty.

 

So when running it should have a permanent live, but this does not mean the ECU is switching it correctly.

Correct, when power is applied across it you will be able to hear it open, if
this is ok then the problem lies elsewhere.

It may just be jammed etc.

It depends, when hot it won’t do anything, so you would not notice any difference. It would only compensate for a heavy electrical load etc.

When cold it will operate and you would notice the difference.

Martin

 

Thanks Martin, as always you’re very helpful and it’s very much appreciated, I’ll try and have a look after work tomorrow, although I’ve owned cosworth’s for years my area of knowledge is with Mk1 Mk2 Escorts, most of my time at work these days is spent welding so electrical problems just do my head in, it’s something I know sod all about, as the old saying goes, I know just enough to get myself in trouble but not enough to get myself out of it,
Thanks again Martin, fingers crossed it’s just the iscv.

 

Hi Martin, just as a quick test I swapped it over with the one from my Escort and it starts and idles perfectly, I returned the throttle cable back to its original position and perfect, can’t thank you enough, you’ve got me out of trouble again, your help is invaluable,
kind regards and all the best, John

 

No problem, glad it’s sorted.

Just be wary of the aftermarket ones, if you do get another.

The construction is not the same as OE and as such they have to be tweaked to work correctly.

Martin