carl0s Posted August 4, 2009 Share Posted August 4, 2009 (edited) All of the above, intermittently. The car's revs will drop so low that it almost stalls, and sometimes it does stall. Sometimes it over revs. At one point it was revving to 3,000rpm on idle. At Halfords a couple of weeks ago, picking up some carb cleaner to clean the ICV, the car just wouldn't start at all. Almost as if there was no fuel coming through. I left it and tried 5 minutes later and it started OK. I then cleaned the ICV, although it didn't look too grubby anyway, and as soon as I started the engine afterwards it just stalled straight after starting, three times. Then fourth time around it ran OK, and I thought it was OK. Now it has just stalled at traffic lights and refused to start. Only thing I can think that's happened is that the valve stem seals and cambelt were changed about two months ago, but this problem only started happening two - three weeks ago. Any ideas? Next on my list is the TPS. Does that sound like a likely cause given the above symptoms? cheers! Carl Edited August 4, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
caseys Posted August 5, 2009 Share Posted August 5, 2009 Maybe your ICV is actually completely shot? Whilst you've cleaned it that maybe hasn't sorted out the issue it's been having. Quote Link to comment Share on other sites More sharing options...
Yaz Posted August 5, 2009 Share Posted August 5, 2009 It could a number of problems, I currently have exactly the same problem with my 93 n/a, and mine is over fueling. Initially it had the same symptoms as you have described, so I had the ISCV changed, and now although it idles normal and doesn't stall anymore, it is still running rich. So, now I'll be looking to change the o2 sensor. By the way, do you have any excess smoke coming out of exhaust? If you do, then black smoke means over fueling and white means running lean. Either way, it could be your ICV or TPS. Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 5, 2009 Author Share Posted August 5, 2009 I suppose I do need to see if the ICV moves or whatever it's supposed to do. It all looked nice inside though. No smoke whatsoever since having the stem seals done. Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 5, 2009 Author Share Posted August 5, 2009 TPS seems to be doing what it's supposed to do. I had a look at the ICV, and here's what I observed: As soon as the car is started, the ICV opens and lots of air comes in. The ICV seems to stay open all the time until the engine is switched off, at which point the ICV closes. Does that sound right or wrong then? Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 5, 2009 Author Share Posted August 5, 2009 (edited) I think I might have found & fixed the problem. On the ICV, the plunger end of the stepper motor - the bit that is pushed out by the stepper motor to block the intake of air - well it had some gunky crud/crap around its collar, in just the right place for making it stick/jam whilst out, so blocking air intake. Blocking air intake there causes the engine to die just like it has been doing. It all depends how strong/weak these stepper motors are though I suppose. I'd have thought with the gearing being what it is, that the stepper motor should have been able to move in/out regardless of this gunk. Car seems fine now anyway, but I'll know for sure within a few days once the missus lets me know. Edited August 6, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 5, 2009 Author Share Posted August 5, 2009 The black bit on the right is the plunger I'm talking about, the bit on the left is the bit that it blocks to stop air intake. http://www.css-networks.com/icv.jpg Does this sound at all likely, or is the stepper motor really strong? Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted August 5, 2009 Share Posted August 5, 2009 That could well be it mate. Quote Link to comment Share on other sites More sharing options...
w41k3r Posted August 6, 2009 Share Posted August 6, 2009 mine is doing this as well would like to sort it, if i take it off does it just go back on the way it come of or does it have a certain way or exact position it has to go back on if you understand what i mean thanks Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted August 6, 2009 Share Posted August 6, 2009 It can only go back on one way. Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 6, 2009 Author Share Posted August 6, 2009 The only thing you can get wrong is if you take off the three screws from the stepper motor and take it apart, you can put it back together with the socket/connector pointing in the wrong direction so the plug/wire doesn't reach it. Quote Link to comment Share on other sites More sharing options...
carl0s Posted August 12, 2009 Author Share Posted August 12, 2009 (edited) car is still playing up. I reckon the TPS could need replacing. When it is idling properly, it seems to drop in revs (close to stalling) when you hit the gas to set off. Any suggestions - TPS or ICV? Edited August 12, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted August 12, 2009 Share Posted August 12, 2009 car is still playing up. I reckon the TPS could need replacing. When it is idling properly, it seems to drop in revs (close to stalling) when you hit the gas to set off. Any suggestions - TPS or ICV? Try one, if that don't work, try the other Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.