Hi all, I've been having a problem lately that has become worse today.

The idle speed sometimes drops a bit low ~400rpm whilst sitting at traffic lights, but otherwise it would be stable at around 700rpm. When first starting the car the idle sits at around 1200 until you drive the car for around 10mins when it stabilises to 700.

Today the car would stall straight away after starting the car as if it couldn't hold an idle speed. If I start the car and immediately hold the throttle it will idle fine until I let go of my foot, after which it'll stall after about 10secs.

From my reading of prior threads and the Gregory's manual I have a few ideas;

- Fouled spark plugs (last time I changed was about 10,000kms ago and found they were quite fouled). Possible worn piston rings or valve stem seals?

- ISC motor faulty/dirty throttle body or idling channels. I have cleaned all these components about 10,000kms ago also.

- Have changed high tension leads, distributor cap + rotor at 10,000kms ago so these shouldn't be a problem.

- Possible fuel pressure problem? I use Optimax for the past 4 years so the pipes should be nice and clean. Will have to get my mechanic to check pump/filter/pressure if required.

Tomorrow is sunday so I will sleep on it tonight then bust out the tools tomorrow. Has anyone got any further ideas?

Thanks all,

JiM

well i had something similar. I had it where it would start and immediately stall. And if you used the throttle and let it out slowly it would idle normally. If you let the car warm for a while you can drive properly, but if you try and drive straight away when you let off the throttle it would bottom out and die.

I had no idea what it was until i found it was the PCV valve, it was clogged.

I thought i had a lemon, coz this was the first day after i bought it lol.

My thoughts are it could be that, or one of the billion sensors

I have just replaced the spark plugs + cleaned PCV; throttle body, MAF sensor connector. I am checking the ISC motor as per http://www.nardek.com.au/testisc510-10.htm. The iSC motor checks to be OK however there is no power at the wiring connector?

It suggests to check the wiring to the control relay however I am not sure where/what this is. The harness goes into a huge bunch of loom that connects to the thermostat and a couple of other small harnesses near the FPR, then disappears through the firewall??

Arg it was stalling all the way home today when I was picking up the spark plugs; I had to hold the revs up manually and was dreading red lights.

I would be more thanhappy to have a look for you.
HVe you tried to re set the base idle speed yet

i had something similar happen to me although my problem was just shit petrol from a no name petrol station.
i put some engine cleaner in with decent fuel from a decent petrol station and i havent had the problem again.
now a days i only get petrol from mobile, shell or BP.

Yeah I haven't eliminated the possibility of bad fuel yet; I recall once I had a poor batch from Shell Vermont South which gave me a great loss of power so I was using BP Ultimate for a while. The last tank was on thursday evening from Shell VS again but the stalling didn't start until saturday arvo :?

Mal I will try setting the base idle tomorrow maybe; I went out just then and the strut brace is in the way of the adjustment screw. At the moment it is idling at 600rpm which I believe is the lowest amount recommended.

After the work today it seems to be running a bit better but hopefully I make it to work tomorrow. On the other hand I wouldn't mind not being at work ;)

[quote:b51f2f9649]The iSC motor checks to be OK however there is no power at the wiring connector? [/quote:b51f2f9649]

I rechecked that and all is OK; the directions aren't too clear and I thought I was to check pins 5&2 together, however upon inspection of a wiring diagram the two pins are connected to the same wire, and so they must have meant check 5 & 2 with ground for power. :oops:

make sure you cross the check connector before the base idle test as 600rpm running on normal idle is a bit low

Yep short pin 10&12 :D It's an annoyance working until 6:30 in summer as I come home and am shit tired/it's too late to work on the car. I have ran the car for a few starts an hour apart to give it a hot/cold cycle and it hasn't stalled since I did the work today.

Some time during the week I may do a shift swap and come home early so I can adjust throttle stop screw/TPS/throttle cable/base idle.

Thanks so far for the help guys :)

Well I made it to work and back today with no problems so it's all looking good =). The idle was bordering on 550/500 and I thought it'd stall but it held out until I got home. Busted out the tools to get to the idle adjustment and it is sitting nicely at 800 constant now.

I blocked off the intake resonators yesterday as well, and shit the induction is loud now; it's like a deep burbling sound when you hit about 4000rpm. The new plugs are letting it rev a lot quicker too (advanced timing by 2deg also).

All is good :D.

If you want interesting fun, have a faulty battery, and a car that doesn't idle properly...