Gti6 Engine Stalling When Coming To A Stop

[2052006 10]

Reason I say other than obvious stepper motor, is that mine is a brand new genuine one from ECP only a couple of months ago, so am assuming this is ok.

 

Today, having started it up from warm, it started to stall at several junctions. I had to have come to a complete stop for it to die, but the revs would simply drop - it wouldn't hunt or stutter or anything. But in a typically French way, it seemed to fix itself for the rest of the way home!

 

Any other sensors I should check that would cause these symptoms? Although, I have to say, it does seem very much like a stepper motor problem...

 

Pete

[ade 4wd 11]

Check the vehicle speed sensor on the gearbox is working. It lets the engine ECU know that the car isnt moving and to go into idle mode.

[Bakes100 20 1 Cars]

Check your throttle position sensor , on mine one of the wires was broke and caused this to happen occasionally, only seemed to stall when i was coming to a halt, when i was stationary revving it was fine

[rubyna 4 1 Cars]

Is the resonator box still on your engine? if so that hasnt blown has it or if you havent got it on like i havnt on mine is the bung still plugged up?..

[gti-si 0]

Won't be the resonator. You have to rev the balls of it to get anywhere, it just dies instantly without gas because of the gaping airleak.

 

Mine did this the other day, just driving, came to a stop, and the engine just died without any struggle, got rolling, bumped the clutch and carried on, then tried diping the clutch whilst moving, same again, revs fell and it died, stopped at the lights, engine died, switched of the ingition, started her up and it never happened again...

 

I know my lambda isn't plugged in proeprly as I've furbard the wires coming from it and I suspect theres a dodgy sensor, and I'd think it was the TPS and stepper, as I sometimes have a high idle when warm, which seems to be fixed on ocassion by bringing up the bite to lower the revs back to 900 and it stays.

 

Very strange but I'd think, TPS or Stepper. Map would introduce other running issues. Ofcourse, the lambda could be knackered, but I think that toowould casue other problems

[gti-si 0]

Check the vehicle speed sensor on the gearbox is working. It lets the engine ECU know that the car isnt moving and to go into idle mode.

 

This is something that's been niggling away at me. I don't like having this disconnected but I've only a mechanical output for the minute, and I've noticied the flat spot it leaves up until ~1500rpm. Does it actually have any other negative effects on the idle etc?

[2052006 10]

Well, I've just checked the supply voltage to the TPS and it's showing 5V - correct I believe.

 

For info - I have a brand new lambda sensor too (Bosch) all properly connected.

 

Checked the VSS is still connected and it appears to be fine.

 

Taken the stepper off just to check and this appears fine, visually, too. Like I say it idles perfectly the rest of the time.

 

It could of course be the operation of the TPS, so I'm going to attempt to test that now...

[2052006 10]

Unless I'm doing this incorrectly, following the guide on testing sensors from the 306 forum, whilst I get the correct 5v supply (pins 1 and 2) I am getting no voltage between pins 1 and 3 - including when I open and close the throttle. Fubared TPS?

[2052006 10]

I just started it up again and disconnected the TPS, expecting it to make no difference once disconnected if it was up the spout, but no - it did make a difference ie. nearly stalled, similar to when you unplug the map sensor. Confused now.

[gti-si 0]

With these being a sensor and not a switch, is there any chance they can give false readings? Or is it a case of it's either fubar or working?

[Bakes100 20 1 Cars]

Gti-si mine currently does exactly the same thing, randomly idles high at around 2000 when warmed , if i bring up the clutch it usually drops back to normal, did this before the TPS issue but since i have fixed it there has been no difference, i'm thinking its stepper related as this is now the only possible sensor I haven't replaced!

 

Another thing when my TPS was causing me problems i held the throttle very slightly depressed and the revs would raise slightly then slowly drop back to tickover, then when i released the throttle it would stall instantly, which was identical when it was unplugged, as my cable was damaged.

 

 

Very annoying problems as when I have the time to fix these issues it works perfectly!

[gti-si 0]

Hmm strange. I'm going to guess on stepper motor. I think someones put a cheap oneon mine so I need to replace it. I'll have a play with it it and see if I can find the fault.

[2052006 10]

Well, since playing about with the sensors this afternoon, I couldn't find a definite cause. Possibly the TPS, BUT, it has fixed itself for the time being

 

I have since been out for a drive in it and gave it some abuse against a Cooper S - got a big grin from the driver - drove it in traffic and got it nice and hot to try and replicate the circumstances it did it in this morning, but still it refused to stall, was spot on in fact. FFS!

 

On a side note, I also swapped my expansion tank cap from my vts rad cap to my old 205 8v one. And this doesn't seem to have leaked at all, whereas with the vts one and the abuse I just gave it, normally a little coolant would seep out of the overflow.

 

No doubt next time I drive it, it'll stall in the middle of a roundabout and the tank cap will fire itself through the bonnet.

[welshpug 1,666]

do bear in mind that the vts rad cap may not fit properly due to the lugs on it.

[2052006 10]

Well, since putting another 100 miles or so on it including a 90-100 cruise, no leaks at all.

 

However, re the stalling issue, it did it again. I'm coming to the conclusion that it will only do it when it's started from warm. Would this point to something in particular such as the ECU temp sender?

[maxi 36 1 Cars]

VSS. They go faulty and intermittently cause this stalling.

 

Maxi