Running problems

[clipperjay]

The ISV i changed it for is off my other 16v, which was working ok. Cleaned it our before I fitted it. I only changed one as it wasn't giving me a reading on the dash. I then double checked that all three gave a reading on the dash. The plugs haven't been changed in a while, nor has the oil. I'm thinking of disconnecting the crankcase breather and allowing it to vent to atmosphere to see if the problem is better. Only because I don't get paid until Thursday and cannot do an oil or plug change. I've heard that some people have solved idle problems because their dirty oil was allowing fumes into the air box via the crankcase breather.

Thanks for your help once again!

Thats what I was leading to heavy oil vapour fouling the plugs could cause start up issues!

[klapwijk]

I will check these things tomorrow. Still not sure what else to check for, the intermittent hunting is weird! Like I said, if I tap the throttle a few times it stops hunting! Any thoughts on this?

On your golf if you disconnect the isv electrical connection does it cut out? My other gomf does, but on this one the revs just drop down by a few hundred rpm?

[clipperjay]

All I know is unless the throttle switch is in the closed position, the ISV circuit is not engaged at all.So make sure you have voltages to the micro switch. (Plus check the position of lever hits the dam switch!)
There is one more thing you can try, but it might f**k it up even more if you dont know what you are doing is to turn the idle screw out check the rubber seal is not damaged in the screw and its letting more air into the TB? (Its a brass one cant miss it! You might want to mark it with tippex first count the turns)
Some people have taken this out and can't get it back in, or its actually vibrated out and missing letting in too much air.
Try the washing up liquid foam on inlet manifold and the various vacumn hoses.
So have you mucked about with the Co screw on the air box?

[clipperjay]

I will check these things tomorrow. Still not sure what else to check for, the intermittent hunting is weird! Like I said, if I tap the throttle a few times it stops hunting! Any thoughts on this?

On your golf if you disconnect the isv electrical connection does it cut out? My other gomf does, but on this one the revs just drop down by a few hundred rpm?

Okay weird the other ISV sounds shagged if it cuts out, becuase revs should drop, NOT cut out Possible the other golf is running on bypass?? (When a ISV is not working there is a bypass screw at the back of it (paint in yellow paint) Dont touch it its set to bypass to get you home in limp mode)

 

[klapwijk]

Inlet manifold has new gaskets, I'm going to torque all the bolts up tomorrow just to check anyway. I've adjusted the micro switch and checked that the TB is not sticking at all. I've had the idle screw out and it looked like it was in ok condition. I've got another screw so may try that anyway. CO has been set up by a garage with me there to 2.05%. Weird what you've said about the limp mode as sometimes the car reads ~500rpm on the dash and sometimes 1000rpm. Although I think the dash is playing up; it does idle at about 500-800 on a cold start. I'm going to double check all the hoses tomorrow and reset the idle after checking the screw.

[klapwijk]

No joy so far today. Took off crankcase breather pipe to air box, double checked vacuums and breathers. Disconnected overrun electrical connector and the car just idled at 2000rpm. Reset the idle speed and CO again with the red connector disconnected and it idled at 1050rpm. Switched off the car and then started it and it idled at about 900-950rpm? This has me thinking the idle controller behind the dash could be faulty. Tried disconnecting the cold start valve while it was hunting and it didn't make a difference. I am running out of ideas now!

[clipperjay]

950RPM is about right, hunting gone? job done!
 

[klapwijk]

Nope still not gone! I had the car ticking over for about 15 minutes, drove two minutes down the road and the hunting came back! It seems to do it once its up to operating temperature!

[clipperjay]

Fifth injector could be stuck and running rich?
Give it the Italian tune up guide!
Take it on the motorway rev it up to red line then slam it into third gear that should clean some soot out of the system
(JK)

Just bite the big one and get a new ISV and controller from what you have said I dont think the other golf is running right either?
You havent done plugs and oil yet have you?

[klapwijk]

I'll try the controller from the other golf, the other golf ran spot on. Not one thing has gone wrong with it in over a year, starts first time every time within a second. No trouble starting in the winter or rain. I think the ISV from the other one was just dirty. I've got another ISV sitting in the garage as well so I'll see how that is.

To replace the fifth injector is it just a case of unplugging it, undoing the fuel line, unbolting it and replacing it?

Haven't done plugs or oil yet, but I will get some on thursday.

What I am most confused about is why after setting up the CO it ran fine for two days; and now all of a sudden the problem has come back, but only happens when the car is warm?!