Cold starting problem.
15 October 2008, 08:56 PM
#1
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Location: Stirlingshire; Wrx type RA STi version 2 V-Limited; #097/555
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Cold starting problem.
I'm having a strange problem with my car (STi Ra Ver2). The car runs perfectly in every other way except in this one condition, when it's started from stone cold it starts first time as always but it idles at about 500 to 600 revs for three or four seconds and then it picks up to the usual ~1500 rpm (or if it's cold it'll stall).
I don't like it idling at such a low level so when it does this I switch it off straight away and start again, now it starts almost as it should (catches and up to 1500 rpm). The idle is perfect in every other condition.
I don't know if it's coincidence or not but this first started to happen as I was resetting the ECU about a month ago.
Since then I've reset the ECU a couple of times (there's never any CELs or fault codes when this is happening), taken the idle control solenoid off and cleaned it, cleaned the spindle and checked it moves freely, checked for > +10 volts on the center terminal (it was ~11.5v), checked the solenoid resistance of both sides (9.3, 9.4 Ohms).
I bought a second hand idle control solenoid to try and after fitting it the car started from cold as it should for the first time in a month (I thought I'd cracked it), but after the second or third time it had gone back.
Some history on the car, plugs are new, coil packs recent, coolant temp sensor recent, Maf recent, lambda new, fuel pressure is set to what I believe is standard ~2.1 bar at idle vac connected.
Any help would be appreciated.
Thanks.
I don't like it idling at such a low level so when it does this I switch it off straight away and start again, now it starts almost as it should (catches and up to 1500 rpm). The idle is perfect in every other condition.
I don't know if it's coincidence or not but this first started to happen as I was resetting the ECU about a month ago.
Since then I've reset the ECU a couple of times (there's never any CELs or fault codes when this is happening), taken the idle control solenoid off and cleaned it, cleaned the spindle and checked it moves freely, checked for > +10 volts on the center terminal (it was ~11.5v), checked the solenoid resistance of both sides (9.3, 9.4 Ohms).
I bought a second hand idle control solenoid to try and after fitting it the car started from cold as it should for the first time in a month (I thought I'd cracked it), but after the second or third time it had gone back.
Some history on the car, plugs are new, coil packs recent, coolant temp sensor recent, Maf recent, lambda new, fuel pressure is set to what I believe is standard ~2.1 bar at idle vac connected.
Any help would be appreciated.
Thanks.
16 October 2008, 05:22 AM
#2
Hi, could try cleaning your ICV, get some carb cleaner then gve it a blast. Also that fuel pressure sounds low, although i may be wrong. What is it set to with the vac line off?
16 October 2008, 06:33 PM
#3
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Location: Stirlingshire; Wrx type RA STi version 2 V-Limited; #097/555
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The fuel pressure is right for my year of car (afaik) ~2.7bar. It gives me the right MPG for my usual journeys. I always keep an eye on how many miles I get from a full tank since I got the car (when it had a std pump and reg, it's now got a walbro and adjustable reg).
D'oh, I think I've made a rookie mistake, the first thing I should have checked. The battery. It didn't feel low so I didn't check it, but it was reading only 12.1 volts after it'd been sitting all night. I put in a known good battery from another car and it started perfect. I'll see how it goes over the next week or so.
D'oh, I think I've made a rookie mistake, the first thing I should have checked. The battery. It didn't feel low so I didn't check it, but it was reading only 12.1 volts after it'd been sitting all night. I put in a known good battery from another car and it started perfect. I'll see how it goes over the next week or so.
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