High idle speed - sierra 2wd cosworth
#1
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High idle speed - sierra 2wd cosworth
Hello all
Recently picked up a pretty clean sierra sapphire 2wd, drives very nice - mileage 107,320 from new but I've noticed the idle speed when started is the same even when up to running temp a bit fast in my opinion. It sits at 1100 rpm and does not drop. Is there any thing I can check or clean out ?
Is this the norm or are they meant to drop down below 1000 when at running temp. Car is totally standard not been modified at all
I'm pretty new to the cossie scene - im used to working on a old cvh
Thanks
Clark
Recently picked up a pretty clean sierra sapphire 2wd, drives very nice - mileage 107,320 from new but I've noticed the idle speed when started is the same even when up to running temp a bit fast in my opinion. It sits at 1100 rpm and does not drop. Is there any thing I can check or clean out ?
Is this the norm or are they meant to drop down below 1000 when at running temp. Car is totally standard not been modified at all
I'm pretty new to the cossie scene - im used to working on a old cvh
Thanks
Clark
#2
PassionFord Post Whore!!
iTrader: (4)
You could try adjusting the idle screw on the throttlebody. Be aware that the throttle position sensor can cause a high idle if it's not set correctly, although if that's the cause i think the idle is usually higher than what you have.
#3
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iTrader: (1)
Idle when at running temperature should be 850-900 RPM.
Turn all electrical equipment off and then with the engine running, disconnect the ISCV connector, this is behind the hose coming from the header tank in your picture.
This shouldn't make any difference in speed, you need to undo the locknut on the T/B, then tighten the screw which will lower the speed, when you get the above figure tighten the locknut.
Reconnect the ISCV, at which point the speed should momentarily increase and then drop again.
You are lucky to find a standard example!
Martin
Turn all electrical equipment off and then with the engine running, disconnect the ISCV connector, this is behind the hose coming from the header tank in your picture.
This shouldn't make any difference in speed, you need to undo the locknut on the T/B, then tighten the screw which will lower the speed, when you get the above figure tighten the locknut.
Reconnect the ISCV, at which point the speed should momentarily increase and then drop again.
You are lucky to find a standard example!
Martin
#5
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#8
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Starts first time every time and got plenty of power
Had it serviced at ford last week as it's only done 4000 miles since 2004 !
It's had a new ford fuel pump & fuel filter last year at a ford dealer on top of a full service.
Last edited by Knuckles84; 31-05-2014 at 05:34 PM. Reason: Adding extra info
#9
15000
Thread Starter
Cleaned out the iscv with brake cleaner - didn't help it much
Ran lumpy for a minute then back to the high idle.
Gonna put it on the mot gas analyser on Saturday to see of that can pin point if it's a vac leak. It's just strange that when you unplug & reconnect the iscv it don't make any difference to the engine speed
Ran lumpy for a minute then back to the high idle.
Gonna put it on the mot gas analyser on Saturday to see of that can pin point if it's a vac leak. It's just strange that when you unplug & reconnect the iscv it don't make any difference to the engine speed
#12
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Fitted a new idle valve today - and still if u disconnect the valve the revs don't drop. Picked up new gaskets from burton power for inlet , & elbow plus box gasket. Need to try them next.
#15
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#16
Advanced PassionFord User
Lovely looking car mate.
#18
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Was driving it last night & briefly it's idle was 850 rpm then minutes later back to 1100,
Putting it on the emmisions tester today to check the mixture before adjusting anything
Putting it on the emmisions tester today to check the mixture before adjusting anything
#20
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#21
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iTrader: (2)
I Wouldn't say there is no air leak. It will only need a very small leak to raise the rpm by that amount, probably not enough to allow it to idle on its own. You could always remove the air filter, make a bung for the hole then pressurise the inlet with a foot pump to see if it holds pressure or not.
#23
PassionFord Post Whore!!
iTrader: (1)
I agree it still sounds like an air leak, as you said you got a pop when spraying around the inlet, try this again, it may be the chamber is leaking.
Martin
#25
PassionFord Post Whore!!
Just watched your video. Are you revving it or is it doing it by itself ? It should have a constant idle on cold start up of around 1050 to 1100 rpm and then settle back down to around 850 to 900 rpm. As you have already changed the ISCV that must be ok, it seems like an air leak to me not electrical. Hope you get it sorted.
#26
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Just watched your video. Are you revving it or is it doing it by itself ? It should have a constant idle on cold start up of around 1050 to 1100 rpm and then settle back down to around 850 to 900 rpm. As you have already changed the ISCV that must be ok, it seems like an air leak to me not electrical. Hope you get it sorted.
I replaced all the inlet manifold gaskets last night - they were all perished so 99% certain that was the problem.
Going to road test it this morning -
#28
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From cold it still goes up and down a bit but when warm it's idles perfect.
Some times it kangaroo's down the road when in gear.
Think it needs base idle and co2 looked at again now I've replaced the leaky gaskets.
Some times it kangaroo's down the road when in gear.
Think it needs base idle and co2 looked at again now I've replaced the leaky gaskets.
#30
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After paying burton power another visit - I was told the iscv can be adjusted if I still have idle issues. So I've adjusted the iscv central nut to match the old iscv - the car now runs near enough spot on.
But like you say book it in for a rolling road setup. I've got a feeling someone just adjusted the base idle to mask the air leak from the inlet gaskets.
Even tried a star tester on it from my ford dealer but it wouldn't connect.
But like you say book it in for a rolling road setup. I've got a feeling someone just adjusted the base idle to mask the air leak from the inlet gaskets.
Even tried a star tester on it from my ford dealer but it wouldn't connect.
#31
PassionFord Post Whore!!
After paying burton power another visit - I was told the iscv can be adjusted if I still have idle issues. So I've adjusted the iscv central nut to match the old iscv - the car now runs near enough spot on.
But like you say book it in for a rolling road setup. I've got a feeling someone just adjusted the base idle to mask the air leak from the inlet gaskets.
Even tried a star tester on it from my ford dealer but it wouldn't connect.
But like you say book it in for a rolling road setup. I've got a feeling someone just adjusted the base idle to mask the air leak from the inlet gaskets.
Even tried a star tester on it from my ford dealer but it wouldn't connect.
#32
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Thread Starter
Refitted original iscv and car starts up spot on from cold now.
Done another gas anayliser test which shows the air leak has gone - inlet gaskets defo the cause.
I'm thinking of giving the engine a "terra clean" before taking it to be setup
Heard it's a lot better than them £5 injector cleaners.
Done another gas anayliser test which shows the air leak has gone - inlet gaskets defo the cause.
I'm thinking of giving the engine a "terra clean" before taking it to be setup
Heard it's a lot better than them £5 injector cleaners.
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