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[JamesV6CDX]

And it goes on...

Let it cool down for hour and a half or so, disconnected batt for ten minutes, then finally got it to start. I'm wondering whether fixing the sensor wiring problem while the engine was warm has confused the heck out of the ECU w.r.t. what's hot and what's cold. Should one ensure that the engine's quite cold before resetting an ECU by disconnnecting batt? Especially if the fault was a temperature sensor? I'm wondering if I've been a bit (!?) daft here.

Anyway, decided it needed a decent run to make up for all the cranking, and this went OK. Still some funny revving stuff at traffic lights, feels like ICV sticking, TPS problem, or an unfortunate combination of the two :-/.  30 miles later decided to head back home, 2 miles from my front door I stopped at a roundabout whereupon the revs died and it cut out totally.
Put the emergency lights on, cranking, cranking, cranking, oh my poor starter motor/engine; started again eventually and got me home.

Can't let my girlfriend attempt to use it in this state. I'll just have to try to get it the 4 miles to my work tomorrow, and try to sort it out there.

If I take the motor part of the ICV off, would it be OK to ultrasonic the valve part in carb-cleaner or equivalent? I'm wondering if there's anything in there that might not appreciate this treatment?

And does anyone know if the throttle position sensor is take-apartable?  I saw one off a golf once with it's lid off, but haven't looked closely at the one on this car.

Thanks, I'll stop whining soon, I promise.

Sounds like you're actually making progress.

Is the EML off? If so, it might be wise to get the codes reset, and see what, if anything, reappears

Take the soleniod off the end of the ECV, and give it a good soak in carb cleaner or something. Make sure throttle body and breathers all clear, and replace with new gaskets, all to the right torque.

Religiously go around the whole engine bay, make sure all connectors are home and you cannot see loom damage. Make sure all vacc pipes are home and secure.

There's not much more this can be now, my money is on a sensor issue, or a sensor not plugged in etc..

[Abiton]

I've not read this thread, so forgive me if I'm off the mark here..

So you're saying that Vx changed the CTS, and charged you for it, when they had not even checked for a short to 0v at it's loom connector, or ECU end?

Auto electronics is my weak point, but even I could tell them to do that.

Muppets. I would demand a refund, on the basis they were "replacing and hoping"

I see what you mean, but that wouldn't be completely fair, because I didn't actually ask them to fix the problem, I just asked them to change the sensor. I was (overly as it turns out) sure this would remove all faults, having visually checked the wiring myself and concluded that it looked OK. So I don't blame them, they offered to do 'further investigation', obviously not for free, but it was my diagnosis that was iffy, not what they did.

Edit: EML hasn't reappeared since fixing the short. I'll have a good look round the engine bay (tomorrow) for connections, air leaks etc. I'll also reset the ECU again with the engine cold. And see if it has any fault codes stored before and after this. It's the trouble starting the engine that's worrying me most just now, hoping that's related to the resetting of the ECU with engine not cold....

thanks for your help chaps, a bit on seems like an unfortunate choice of username right now  

Pete

[JamesV6CDX]

I've not read this thread, so forgive me if I'm off the mark here..

So you're saying that Vx changed the CTS, and charged you for it, when they had not even checked for a short to 0v at it's loom connector, or ECU end?

Auto electronics is my weak point, but even I could tell them to do that.

Muppets. I would demand a refund, on the basis they were "replacing and hoping"

I see what you mean, but that wouldn't be completely fair, because I didn't actually ask them to fix the problem, I just asked them to change the sensor. I was (overly as it turns out) sure this would remove all faults, having visually checked the wiring myself and concluded that it looked OK. So I don't blame them, they offered to do 'further investigation', obviously not for free, but it was my diagnosis that was iffy, not what they did.

Ahh

Difference is though, they're trained up... I would have expected them to get a full overview of the situation before commencing work, including discussion of symptoms and possible other routes of investigation with the customer

But then, this is VX

[Abiton]

They did ask me who had diagnosed the need for a replacement sensor. Had I not replied "I did" quite so confidently, they may have been more thorough. Such misplaced confidence, with the benefit of hindsight  .

Edit: Thursday 0800ish, Well...

Disconnected the batt neg again this morning while I had brekkie. Reconnected and it started, reluctantly. Got me to work too, but the revs were all over the place, particularly when changing up. Also seems to surge at idle.

ICV's coming off at lunchtime for an ultrasonic, and the TPS is going to be scrutinised (dare say I'll have to get brutal with a seam on the plastic enclosure, but it won't be the first time... Hot soldering iron tip has been known to successfully reseal such things). If I stuff it up, Vx place is only a short walk away...A bit on, still.

[JamesV6CDX]

They did ask me who had diagnosed the need for a replacement sensor. Had I not replied "I did" quite so confidently, they may have been more thorough. Such misplaced confidence, with the benefit of hindsight  .

We've all learned through making mistakes, don't worry about it

[TheBoy]

is the cam sensor still showing a fault - this will cause difficult starting.

Additionally, check the loom, seeing as you have already had shorts in it, particularly around the battery tray and abs unit.

[Abiton]

Never saw a cam-sensor fault, but will do another paperclip test at lunchtime (could be a long lunch!)

Will look at loom too, thanks. It did seem to start better this morning than last night, so I'm wondrin if the engine needed to be cold to get the ECU to self-calibrate correctly to the new sensor (or am I over-estimating what it does?).

Thanks to all for continuing support and suggestions.  

[TheBoy]

I'm wondrin if the engine needed to be cold to get the ECU to self-calibrate correctly to the new sensor (or am I over-estimating what it does?).

No, it will work off the real data almost as soon as it gets valid data.

[Abiton]

Thanks again.

Part of my starting problem may have been operator error, I think.

Talking to a colleague who's been wrestling with his daughter's reluctant Mondeo (or suchlike) he Please read the manual'ed and discovered that the foot/pedal scenario is very different than when starting a carbed car, and opening throttle to try to 'help' it will do nothing of the sort. My (other) car is carbed, though with a fully automatic choke that usually requires no go-pedal help, but my instincts are based on cars that do benefit...

Is it true to say that having nobbed up in this fashion, the situation is best recovered by putting foot slowly to the floor before turning the key, and holding it down while initiating cranking? More for me to learn!

[TheBoy]

Start with no pedal at all.

If you suspect its flooded, crank at WOT (on injection cars, this will not fire injectors, allowing you to remove petrol from cylinders).

[Abiton]

Ta.

[penguin79]

And it goes on...

Let it cool down for hour and a half or so, disconnected batt for ten minutes, then finally got it to start. I'm wondering whether fixing the sensor wiring problem while the engine was warm has confused the heck out of the ECU w.r.t. what's hot and what's cold. Should one ensure that the engine's quite cold before resetting an ECU by disconnnecting batt? Especially if the fault was a temperature sensor? I'm wondering if I've been a bit (!?) daft here.

Anyway, decided it needed a decent run to make up for all the cranking, and this went OK. Still some funny revving stuff at traffic lights, feels like ICV sticking, TPS problem, or an unfortunate combination of the two :-/.  30 miles later decided to head back home, 2 miles from my front door I stopped at a roundabout whereupon the revs died and it cut out totally.
Put the emergency lights on, cranking, cranking, cranking, oh my poor starter motor/engine; started again eventually and got me home.

Can't let my girlfriend attempt to use it in this state. I'll just have to try to get it the 4 miles to my work tomorrow, and try to sort it out there.

If I take the motor part of the ICV off, would it be OK to ultrasonic the valve part in carb-cleaner or equivalent? I'm wondering if there's anything in there that might not appreciate this treatment?

And does anyone know if the throttle position sensor is take-apartable?  I saw one off a golf once with it's lid off, but haven't looked closely at the one on this car.

Thanks, I'll stop whining soon, I promise.

Sounds like you're actually making progress.

Is the EML off? If so, it might be wise to get the codes reset, and see what, if anything, reappears

Take the soleniod off the end of the ECV, and give it a good soak in carb cleaner or something. Make sure throttle body and breathers all clear, and replace with new gaskets, all to the right torque.

Religiously go around the whole engine bay, make sure all connectors are home and you cannot see loom damage. Make sure all vacc pipes are home and secure.

There's not much more this can be now, my money is on a sensor issue, or a sensor not plugged in etc..

just thought i'd mention, when i bought mine 2.0 16v gls, it ran fine then developed very weird idling problems and stalling at lights/islands etc, after thoroughly cleaning everything it wasn't too bad but still there, replaced the ICV and it's as good as new now. They are about £35 off ebay, well worth the investment, also give a quick look to the wiring loom to the crankshaft sensor as the coating is prone to perishing which may cause interference, another problem i had with mine, sounded like it was running on 2 cylinders, lol. just unclipped the wire and wrapped some insulation tape to it for now till i can get it changed....just a thought
paul

[Abiton]

Thanks penguin79, the crankshaft wiring thing sounds worth a check, I suppose that's somewhere horribly inaccessible?  
You wouldn't be penguin45 somewhere else perchance?

ICV's just been treated to an entire can of carb cleaner, and is now in the ultrasonic (not the solenoid bit!), getting it's final wash and brush up. Lots of crud in there, 135000 miles worth, or at least since the small breather's been completely blocked...
The far end of the main 'can' where it's assembled through, has a crimped-on end cap, which seems to leak some air, so I'll be sealing that somehow before it goes back on. Can't imagine that's intentional.

TPS a different story. Bit of a battle to get in, but determination'll get me into most things [smiley=wink.gif].
No probs with that. Felt very wibbly and nasty before opening, but inside it was in good nick. Put it on an analogue meter and moved it back and forth, nice smooth change of resistance all the way, either way.  So I think I've ruled out that as a problem. Lid being araldited back on now.

[Abiton]

Reinstalled ICV and TPS without problems.  Started, rather reluctantly after prolonged cranking, and got me home.  But every time I changed gear the revs wound up to about 3K, embarrassing.  When I get home I park up and after maybe 6 seconds the revs drop to around 1150 and sit there steady as a rock. Seems like giving the ICV the cleaning of its life has just made it stranger! Shouldn't it find an 850-ish idle speed?

Read the fault codes again, and we're back to 14 and 15, like before... The Vx peeps said they'd only got 14 after changing the sensor, but I didn't think to check this myself. Thought that the disappearance of the EML light after fixing the short meant the codes would all be gone, especially after the 15 minute batt neg disconnection I did while I had brekkie this morning.

So tried the other method of clearing codes, switching ignition to the position before cranking for 5 seconds, then off 30 times. No change, still 14 and 15. Am I nobbing up this clearing of codes? How should I do it, in detail please (if different from what I've already tried). Beers are on me for the poster who solves this whole shebang, obviously.

Took the ECU right out for internal scrutiny, but no obvious combusted bits, very tidy looking bit of kit TBH.

Tired of this...

[TheBoy]

not sure if disconnecting battery works for 4 pot, certainly won't for the motronic cars.

Best way is a code reader if you have access to one...