Stalling problem

[Red Wedge]

I drove the car up to London the other week to see my girlfriend and it was the first long distance journey I've done it since I've owned it.

There was a massive tailback on the M4 and I sat in traffic for a while and noticed after a while that the car had a tendency to stall if I rolled onto a light throttle then off again to move a few feet with the traffic. It was preceded by a drop in revs and a stutter before dying quietly.

Both water temp and oil pressure are fine so I don't think it's a head gasket. It did occasionally idle lower than usual which made me think it might be an idle issue.

I don't know what the set up is like on the mk1s in terms of idle adjustment etc so any ideas as to whats causing this would be very welcome!

[pk_090]

Might be worth checking the coolant system for air locks, if it not bled properly it can cause a fluctuation in engine revs. There is a mixture control screw on the inlet manifold, i was told that this is a pig to get right so therefore i have never touched it. All the vaccum hoses could be worth checking for leaks also.
Alex

[Red Wedge]

Cheers, I'll have a look at some point and see if anything is amiss. I think the cooling system could do with further bleeding as it does make a few noises when the car is first fired up.

The rad was out and the coolant replaced when it was with Rogue so maybe they didn't quite get all the bubbles out.

[pk_090]

I'd put money on that Rogue know what they are doing. Could also be worth checking plus leads and doing dizzy cap and rotor arm. These might not cure the problem but if they havent been changed in a while will definitely make it run smoother.

[Red Wedge]

Yeah, Rogue know their business but as I know from previous experience bleeding a car is sometimes a lengthy and tedious process!

I fitted new plugs when I did a service not that long ago, will do leads and dizzy too as it seems sensible given the fact that the car was sat for a long time and I don't think it's been serviced in more than a year or two.

[Red Wedge]

Just did a quick visual inspection and nothing seems amiss.

I didn't mention in my opening post that it only really does this when its a hot day and the car is up to temp and in slow moving traffic.

Not sure if that changes anything or not.

Edit: After a bit of research I think it might be the waxstat. Can I blank this off with a valve cap and it will just negate the waxstat or do I have to drill a hole in it to get the car to idle properly?

[jimi]

It sounds very like the waxstat is sticking intermittently and altering the idle.

Can I blank this off with a valve cap and it will just negate the waxstat or do I have to drill a hole in it to get the car to idle properly?

No, you find the car difficult to start and it won't idle when cold if you do that.
Drilling a hole around 4/4.5mm in the valve cap will help but it's not a proper solution IMHO. A Replacement AAV from Mr T, if you can still get one is very expensive. The waxstat's (or AAV to give it it's proper name) main purpose is cold starting/idling, read this article by Paul Woods, it explains all and has a proper solution
http://www.mr2oc.co.uk/know-your-2-know ... kbartid=54
also worth reading these 2 articles as well
http://www.mr2oc.co.uk/know-your-2-know ... kbartid=55

http://www.mr2oc.co.uk/know-your-2-know ... kbartid=56[/url]

[Red Wedge]

Cheers jimi, I saw your handiwork in other threads with the auto choke system you've created, very impressive.

I've looked at the do it yourself method and will probably give that a go at some point as this isn't a massive problem as it is.

Thanks for the advice.

[jimi]

All I did was add a little embroidery to Paul's work, all the credit is his

[Red Wedge]

Haha fair enough, you did say as much but its still a very tidy piece of work.

Was it difficult to do compared to the manual choke from Paul?

[sherwin1983]

Turn the idial speed up on the trottle body justa tweek will do

[SuperRedMR2]

I had this issue constantly for a few months before my head gasket blew up.

My TB waxstat was fine.

The fact that when the radiator was removed, I brushed my finger down the fins and it basically fell to pieces.

Check your radiator as well.