Author Topic: Stalling when clutch is depressed - engine is cold  (Read 2613 times)

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Offline SSS

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Stalling when clutch is depressed - engine is cold
« on: Jan 22, 2013, 06:58AM »
Putting this up in the off chance that others have had this issue; this one has just popped up for me.

327,000kms on the clock. Completely standard. Idles at 850 rpm on the tacho.

First thing in the morning, when the engine is cold, get about 1km down the road to a 50km/h section that I depress the clutch because of those painful "3/4" style speed humps.

Monday morning, idle drops down to just under 500rpms, nearly gets to the point of stalling, but recovers ok and idles at 650-ish rpm. Hmmm, annoying.

This morning, same section of road, depress the clutch, stalls straight away, doesn't ever try to recover. Right....hit the key to start it up again, no problem, idles about 750ish rpm.

As the car comes up to temp a few more kms down the road, idles lower, but not as bad when the temp was cold cold. As it warms up, gets back to normal idle speed of 850rpm. Fully up to temp, no idle issues.


Apart from checking / topping up oil, only touching of the engine has been some cleaning of electrical connectors to help eliminate another niggle it had some months ago. Only gets driven about 150kms per week though usually.

I have a couple of things I am going to try:
The most important and easiest thing I am going to check, is that the crank pulley does not move side to side when the clutch is depressed with the engine running. If it does, it will need a rebuilt motor. No question.
1) Connect with Consult, check and adjust base idle speed and timing if required.
2) Check and clean the terminals in the IAC terminals and plug AGAIN (I actually may replace the plug and terminals on the harness side, I bought new ones not long ago)
3) If no luck with 1) and 2), adjust the throttle hard stop on the throttle body (yeah yeah, band aid fix....there is a reason for this however)
4) Disconnect the AC drive belt to see if there is "resistance" from the AC compressor, even when it is switched off.
5) Find a good IAC valve, clean it up and swap them over. I don't really want to do this, since it's a PITA and I don't really have time. Or, I spend $170 and buy a new one. Only problem with this, is that the fast idle valve sandwiched between the IAC valve and the plenum is not available as a new part, and I would have to swap in a cleaned up used one at the same time)

If you have had this same issue...let me know!

Offline Pure_Sincerity

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Re: Stalling when clutch is depressed - engine is cold
« Reply #1 on: Jan 22, 2013, 08:12AM »
never had the issue, but I have a perfect working IAC valve from my sohc motor you can take.
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Offline SSS

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Re: Stalling when clutch is depressed - engine is cold
« Reply #2 on: Jan 22, 2013, 08:56AM »
I'll let you know aaron, thanks, i've got at least 2 spares at home i can try first.

As part of 1) also, i will be checking the IAC valve resistance in accordance with the FSM specs.
« Last Edit: Jan 22, 2013, 08:59AM by SSS »

Offline SSS

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Re: Stalling when clutch is depressed - engine is cold
« Reply #3 on: Jan 23, 2013, 06:07AM »
Ok:

1) Checked idle speed and timing - idle speed good, timing was down a few degrees; however when I checked it (with the TPS disconnected), i'd just come home from work so the engine bay was still quite hot and could easily heat soak the airbox, meaning that the IAT sensor could have been pulling 1-2 degrees out. Nevermind, i'll check it again this weekend when it's cooler and adjust if necessary.

2) Took the plug off the IAC valve and cleaned the terminals on the IAC valve and the wiring connector on the harness. Actually managed to scrape off some gunk off the terminals on the IAC valve, sprayed some CRC 2-26 on it's terminals and the wiring harness connector, let it dry, and connect it back up.
IAC valve resistance was ok at 12 ohms (considering the FSM says 10 ohms at 20 deg C, however i'll check this again when the car is cooler)

3) I haven't replaced / checked my air filter for a while, so I removed that and tapped out all the crap that had accumulated. Was a bit in the pleats, but nothing out of the ordinary otherwise.

Result: No stalling this morning, however the idle would still drop down to about 750-800 rpms and stay there, quite solidly until the engine was up to temp, in which case it would idle at 850-900.. Both idle valves still probably need a real good clean, but overall, if this has fixed the stalling, i'm happy for now. In any case, I will probably replace the pins / plug this weekend too with a new one I bought a few months ago.

Additionally, since a great deal of our very old wiring harnesses have lost some, if not all tension in the pins that make an electrical connection to a sensor / solenoid etc, i've found CRC 2-26 pretty much invaluable for sorting out intermittent electrical connections. http://www.crcindustries.com/ei/content/prod_detail.aspx?PN=02004&S=Y
I swear this stuff got my SCV solenoid working again...I think the pins inside the plug had lost *just* enough tension to only make it work intermittently, at best, if not at all. Cleaned the pins, sprayed this on, and hey presto.
« Last Edit: Jan 23, 2013, 06:14AM by SSS »

Offline SSS

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Re: Stalling when clutch is depressed - engine is cold
« Reply #4 on: Jan 24, 2013, 05:54AM »
Looking more and more that it was an intermittent / bad electrical connection at the IAC valve.

Offline SSS

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Re: Stalling when clutch is depressed - engine is cold
« Reply #5 on: Apr 4, 2013, 10:53AM »
This ended up being exacerbated by the fact that the base idle speed was down at 500 rpm (with the TPS sensor disconnected per the instructions for setting base idle speed in the FSM) when it should have been at 650 rpm +/- 50 rpm.

Set the base idle by screwing the adjustor out (was nearly all the way in) to just over 650rpm, now when I clutch in and roll to a stop the idle barely drops below 750rpm before recovering. (before it was dropping down below 500rpm before recovering)

Offline Budgie

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Re: Stalling when clutch is depressed - engine is cold
« Reply #6 on: Apr 6, 2013, 05:33PM »
Was probably me that did that yonks ago adam :P
dont piss me off with your pillarless shit captain snappy wrist