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        General >> Problems >> 24V engine stalling
        
(Message started by: Tenfut on Sep 9^th, 2010, 9:29pm)

Title: 24V engine stalling
Post by Tenfut on Sep 9^th, 2010, 9:29pm

My 24v runs fine at speed and idles OK so long as the gear selector is in "D" or "R" when stopped, but as soon as I move the selector to "P" or "N" the engine stalls immediately, it doesnt splutter or gradually cut out it is just like turning off the engine with the key.

Anyone any ideas?

Cheers

Tenfut

Title: Re: 24V engine stalling
Post by scorpio_man on Sep 10^th, 2010, 5:35am

hi tony

i'd give the idle bypass valve a wee clean out with carb cleaner.

remember to use a little oil on the 'ram' pipe once it's clean.

sounds like it's sticking a little.

hth

Title: Re: 24V engine stalling
Post by Tenfut on Sep 10^th, 2010, 6:47am

Thanks Andrew

I will give it a clean this weekend

Tony

Title: Re: 24V engine stalling
Post by Matt on Sep 12^th, 2010, 3:14pm

whats your gearbox like when its driving? whats the oil like? sounds like the box could be the problem to me, could be the selector shafts is lose or could be the solenoids in the box failing, do you get much 'whine' off the torque converter?

Title: Re: 24V engine stalling
Post by Tenfut on Sep 12^th, 2010, 5:13pm

Matt

The gearbox oil and filter were changed 6000 miles ago (@93000) The oil is clean and no bits. The oil that came out didnt seem that bad. As for whine it does a bit when starting off but I think it always has done, difficult to say really. It picks up drive within about 2 seconds and goes through the gears OK. As it is the only one I have driven I have nothing to compare it with.

For one reason or another I have not been able to spend any time on the car this weekend so dont know if Andrews suggestion of cleaning the idle control valve would sort the problem.

As you can imagine I hope he is right!!!

Tony

Title: Re: 24V engine stalling
Post by Tompion on Sep 15^th, 2010, 1:01am

Strange this as obviously you have to start it in N or P.
When it stops can you start it immediately,
does it matter if the engine is hot or cold,
if you start it, move it very briefly into gear then back to N or P does it stop?

I did try removing the start inhibitor whist in gear with the engine running (parked in a suitable way to avoid being run down :)). It made no difference, but just to prove a faulty one can’t cause your problem you could try doing the same & see if yours still stalls.

Title: Re: 24V engine stalling
Post by Cosray on Sep 15^th, 2010, 8:30am

Hi all - here's my two cents' worth.
The transmission range sensor is both a resistor bridge, telling the EEC-V in which position the lever is, economizing on wiring, as well as a slider switch.

This switch, by grounding, energises the Start Inhibitor Relay in position P & N only, which in turn allows the startermotor to run or not. Now, as soon as the engine runs, that wire has no function anymore.

The grounding wire runs to the PATS section of the EEC-V or the PATS module, depending on year of build.

In all other positions it should be open, leaving the Start Inhibitor Relay OFF and the PATS line with no signal at all, "floating".

(Pulling the Start Inhibitor Relay after starting has no effect on the engine running since it will only block the starterengine before starting)

Because of a wiring or switching fault it looks like it is telling PATS to immobilize the engine IN position P & N once it is running, so therefore the immediate cut-out, as the EEC-V stops firing the Injectors.

As it is a mechanical, moving device, it is suspect, since apparently only its movement and change of position provokes the fault.

It probably induces a logical conflict in PATS function as the engine is running already and bridge and switch do not match up.

You would need this diagram "Starting Systems, chapter 26-01-*" for details:

http://www.bitly.nl/00efe9

Even better if you would have a TIS CD-ROM around year 2000, as it connects the various interlinking chapters just by clicking.

What year is your Cossie?

HTH
Ray

Title: Re: 24V engine stalling
Post by Tenfut on Sep 15^th, 2010, 9:05am

Thanks to all for your comments

Auto electrics definitely not my field!!!!

I will start with Andrews suggestion and see where that takes me

Tompion - Where is the start inhibitor?

Tony

Title: Re: 24V engine stalling
Post by Cosray on Sep 15^th, 2010, 9:25am

Tony,
It is in your junction box but, as stated, it has no function AFTER the engine is running.

BEFORE starting it will either prevent or allow the starterengine to engage.

Apparently your engine starts well but suffers from a cut-out in pos P & N AFTER starting.

Most likely the fault is in the mechanical area i.e. the switch part of the Transmission lever, confusing your PATS.

Waht year car please?

HTH
Ray

Title: Re: 24V engine stalling
Post by Tompion on Sep 15^th, 2010, 9:41am

My point was that removing the start inhibitor relay after starting would rule it out.
I'd be very surprised if it was the culprit, but for the sake of a few minutes work it's worth trying.

Title: Re: 24V engine stalling
Post by Cosray on Sep 15^th, 2010, 9:50am

Yes of course Tompion.

However and moreover I would suggest Tony here to put the car under a roof or awning or darkened area and inspect the signals from the LED on his dash.

What signals does it produce:

before starting (KEY OUT, IGN OFF)
before starting (KEY IN, IGN ON)
when starting
when engine running
when the failure occurs.

We could then hope to deduct what symptoms are present under the bonnet.

Here's how it works:

http://www.fordscorpio.co.uk/pats.htm

Tony, over to you

Ray

Title: Re: 24V engine stalling
Post by Highlander on Sep 15^th, 2010, 10:03am

on 09/15/10 at 09:05:00, Tenfut wrote:

Tompion - Where is the start inhibitor?

http://www.fordscorpio.co.uk/images/central_fusebox.gif

Start inhibitor relay = R11 drivers side fusebox at the very back Tony, small brown one

its helpful to stop the wipers in the up position to gain access and I find I sometimes have to remove some of the surrounding relays to get a grip of it

Title: Re: 24V engine stalling
Post by Tompion on Sep 15^th, 2010, 10:10am

Brown? mine was yellow - normal size

Title: Re: 24V engine stalling
Post by Highlander on Sep 15^th, 2010, 10:15am

on 09/15/10 at 10:10:24, Tompion wrote:

Brown? mine was yellow - normal size

Now thats interesting, never seen that before, all the ones I've seen have been half size relays with brown covers, was yours in the same place? R11?

***Just had a quick look round some cars/fuseboxes, I have different setups right enough, some have a small white R10 horn relay with small brown inhibitor relay (2 x facelift 24v's) , some have a brown horn relay with large yellow inhibitor relay like Tompions..

I wonder if they should be the same and have suffered from people swapping relays or if there were different relay set ups... I give up with Scorpios!! ;D

Title: Re: 24V engine stalling
Post by Tompion on Sep 15^th, 2010, 10:47am

;D

Thought I must be going daft so went out and checked/pulled a couple of relays. Definitely yellow on mine with 6HE in the corner. The horn R10 alongside is a small brown one.

Title: Re: 24V engine stalling
Post by Tenfut on Sep 15^th, 2010, 11:20am

Built December 1996

Tony

Title: Re: 24V engine stalling
Post by Tenfut on Sep 16^th, 2010, 8:41am

Tried an experiment this morning

Started engine from cold, moved selector to "D" then back to "P" and then through every position, no problems at all.

Drove 5 miles, engine now up to temperature, stopped, put car in "N" stalled immediately.

Re-started engine in "N" and it ran perfectly, put it in "D" then back to "N" and it stalled.

Anyone any ideas

Tony

Title: Re: 24V engine stalling
Post by Cosray on Sep 16^th, 2010, 9:11am

... seems to point to a "slippery" or erratic sliderswitch under the lever, upsetting PATS's conditions, cutting-out the Fuel Injectors.

Once the vehicle has moved, providing VSS data to the EEC-V, an eveidently wrong PATS "ON" condition is conflicting.

Tony, have you observed the various LED signals before, during after? What do they say? They might provide a clue to the stalling.

HTH
Ray

Title: Re: 24V engine stalling
Post by Highlander on Sep 16^th, 2010, 9:30am

Tony have you had a wee look for air leaks?

from the MAF back, check there are no splits/gaps in the hose, jubilee clips loose.

I'd also look under the engine cover, the O rings at either end of the inlet manifolds are prone to leaks as well as the small rubber hoses and T piece.

You might need to have someone in it and keep it in D so it still idles if it keeps stalling though.

I usually spray some WD40 over the O rings/pipes, if its leaking you should hear a change in the engine note as it draws it in.

http://www.fordscorpio.co.uk/vacuumpipesg.htm

Can you get an OBD scan?

p.s. as an outside shot, does it still stall if the aircon is turned off??

O-Rings at rear right as you look front the front

http://www.fordscorpio.co.uk/images/vacphoto4.jpg

Title: Re: 24V engine stalling
Post by Tompion on Sep 16^th, 2010, 11:56am

I would imagine increasing the revs as you change to N would allow the engine to overcome a problem with air leaks. If it’s reluctant to do it because of the drag when stationary or you don’t want to try it on the move (as brakes and steering become useless with a dead engine) then chock the front wheels & jack one of the back wheels off the ground so it can spin.

Title: Re: 24V engine stalling
Post by Mike H on Sep 16^th, 2010, 2:10pm

I still think it's electrical. PRNGL switch affecting PATS is a good candidate.

Title: Re: 24V engine stalling
Post by Highlander on Sep 16^th, 2010, 2:36pm

I must confess to not really understanding Cosrays detailed info on the electrics, although he certainly knows his stuff, electronics just go right over my head ;D

I cant understand the connection between selector position and PATS cutting the engine off.

surely if it were PATS related it wouldnt restart?

All Tony has to do is turn the key after it has stalled and it restarts.

Title: Re: 24V engine stalling
Post by Mike H on Sep 16^th, 2010, 3:08pm

It's bizarre alright!

Title: Re: 24V engine stalling
Post by Mike H on Sep 16^th, 2010, 3:14pm

As 'P' and 'N' ground a wire, else not, that's where to start looking.

Imagine damp in a connector, or two bare wires together, one wire is grounded by P or N, suddenly the other is too. Jolting about by vibration, heating up, cooling down, means it only does it sometimes.

Title: Re: 24V engine stalling
Post by Highlander on Sep 16^th, 2010, 3:32pm

I'm not having it! ;D

Tony, do you get a PATS code flashing when it cuts out?

If you give the engine some load, heater fan, Aircon, lights, heated screens etc will it still stall? does it stall with no load?

Title: Re: 24V engine stalling
Post by Tenfut on Sep 16^th, 2010, 3:56pm

Will experiment again tomorrow morning

Tony

Title: Re: 24V engine stalling
Post by Tenfut on Sep 17^th, 2010, 12:41pm

Update

As yesterday started from cold, moved selector through all positions, engine didnt stall.

Switched on A/C, Heated seats, Both heated screens, radio, again engine didnt stall.

Drove 7 miles, engine now hot, moved selector to "N" and sure enough engine stalled.

Re-started in "N" moved to "D", switched everything on as above and moved selector
back to "N" and youve guessed it, engine stalled, no flahing from PATS.

Conclusion -- this only happens when engine is hot and makes no difference what is switched on.

Tony

Title: Re: 24V engine stalling
Post by Highlander on Sep 17^th, 2010, 1:16pm

Have you cleaned the idle bypass valve Tony?

Title: Re: 24V engine stalling
Post by Tompion on Sep 17^th, 2010, 1:21pm

& this is the way round it should be :)
http://www.fordscorpio.co.uk/24vrebuild.htm

Title: Re: 24V engine stalling
Post by Highlander on Sep 17^th, 2010, 1:23pm

lol I've seen them on the wrong way before! but it increases the idle speed and makes the rpm hang after revving it

Title: Re: 24V engine stalling
Post by Tenfut on Sep 17^th, 2010, 1:24pm

Thanks Stuart and Dave

Cleaning it tomorrow

Tony

Title: Re: 24V engine stalling
Post by scorpio_man on Sep 17^th, 2010, 10:10pm

hi there

could also be a faulty lambda sensor or maf. :-/

still, we'll see after the valve clean up.

Title: Re: 24V engine stalling
Post by Tompion on Sep 18^th, 2010, 12:44am

Yes, I was wondering if there could be a wiring problem with a lambda sensor lead flexing that occurs when the engine moves as it goes out of gear.
Might be worth seeing if it happens sooner than 5 miles down the road – say half a mile i.e. long enough to have reached closed loop conditions rather than warmed up (not that it will actually be closed loop at tickover).
It’s the sudden death that doesn’t make sense especially as it’s when load is taken off. Certainly sounds more electrical.

Disconnecting the MAF should rule out a faulty one.

Did you put your hand over the PATS light, it can be really difficult to see it flashing.

A scan would probably be helpful.

Title: Re: 24V engine stalling
Post by Cosray on Sep 18^th, 2010, 10:00am

Hi all, upon returning studied this thread as it's developing. Based on what I read my take is definitely electrical.

It seems to point to the engine cable loom, also called - very aptly - fuel cut-off loom.
This loom carries the leads from the connector under the ABS module, along the coilpack, over the injectors to the autobox, driving the solenoids and receiving VSS and PRND21 signals. Also it incorporates the wires from the CPS to and from EDIS and coilpacks, another favorite culprit.

This loom proved rather vulnerable to heat and moist. Especially between the engine banks and the section behind the engine, along the exhaustpipes towards the autobox, you will find hot sections.

In my opinion three clues point to the loom and/or gear lever switch:

No fault when cold, only after heating up, driving and mechanical movement.
Second, fault is provoked by nothing else than lever movement.
Third, engine seems to be completely and abruptly immobilised.

Apparently, when hot, while engine running and lever moving, the EEC-V receives a false positive to PATS, reacting by cutting the injectors off.

It does NOT go into LOS; it immobilises, which is what PATS is supposed to do to the EEC-V.

When restarted = resetting, everything reacts normal again until P or N is switched.

I would suggest inspecting the engine-loom from beginning to end and, while at it and under the car, inspect the gearlever switch and bridge and possibly messed up/damaged/open wiring.

My Cossie had similar and othe erratic symptoms 4 years ago and replacing this loom, of which the isolation had become brittle and partly exposed its strands, cured all of them in one go.

Do not confuse with the engine compartment loom which I had replaced recently; that's a different troublemaker :-(

Have you inspected the LED flashing sequence in a dark area, when the fault occurs, with engine stalled AND IGN still ON?

What sequence after KEY OFF > IGN ON?

HTH
Ray

Title: Re: 24V engine stalling
Post by Mike H on Sep 18^th, 2010, 9:07pm

^ what he said. ;D

I have hinted at it a couple of times, now there's two of us

Title: Re: 24V engine stalling
Post by Highlander on Sep 20^th, 2010, 9:50am

on 09/17/10 at 12:41:14, Tenfut wrote:

no flashing from PATS.
Tony

Title: Re: 24V engine stalling
Post by Cosray on Sep 20^th, 2010, 9:59am

No flashing is very suspect... LED broken perhaps?

Ray

Title: Re: 24V engine stalling
Post by Highlander on Sep 20^th, 2010, 10:05am

You're trying to make it fit Ray ;)

Tony does your Light flash when you lock the car as normal?

Title: Re: 24V engine stalling
Post by Cosray on Sep 20^th, 2010, 10:36am

Sure Highlander this is no courtroom but... we volunteering remote autodoctors can only diagnose by what the patient says, right? ;D

Four times in this thread the LED flashing question was raised for signals before, during and after - and the single answer is "no flashing".

Tony, over to you, pls clarify if needed.
Ray

Title: Re: 24V engine stalling
Post by Tenfut on Sep 21^st, 2010, 8:40am

Progress!!

Due to early retirement of my central heating boiler on Saturday work on the car had to be put on hold.

However last night I took the engine cover off, cleaned with carb cleaner every multi-plug I could find, tightened every hose clip and took off the idle control valve to clean. I then remebered that I had a brand new one, bought years ago to try to cure a hanging throttle(it didnt so I took it off again) put the new one on and took the car for a run of about 3 miles, moved the selector through every position and no stalling, not even a drop in revs. This morning did my normal 7 mile journey and again no problems. I wont get too excited until I have done a few more journeys but it does look good.

I suppose in hindsight I should have done the cleaning/hose tightening/valve changing one at a time so as to identify the problem.

Many thanks to everyone who contributed their thoughts and ideas on how to solve this problem

Tony

Title: Re: 24V engine stalling
Post by Highlander on Sep 21^st, 2010, 9:10am

Excellent ;D

Title: Re: 24V engine stalling
Post by Cosray on Sep 21^st, 2010, 9:19am

... great news.... It's the result that counts! Good oldfashioned nuts-and-bolts stuff, some grease and some oil... Go! ;D ;D ;D

Ray

Title: Re: 24V engine stalling
Post by Mike H on Sep 24^th, 2010, 2:07pm

Majik ;D hope that is all there is