Ford Scorpio Forum - Print Page


    
      
        Ford Scorpio Forum
        (https://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl)
      

        General >> Problems >> 24V Cosworth mystic stalling problem
        
(Message started by: theogrenietis on Jul 25^th, 2018, 4:37pm)

Title: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 25^th, 2018, 4:37pm

Hey guys, I`m new to the forum, but I have high hopes that some of the guru`s here will help me.
So I purchased a 95 ultima cosworth in november, for 450 EUR (400GPB), with 280 000 km (173k miles) on the clock, in very good condition.
First 2000 km the car ran flawlessly, but after that, it developed a misfire at high revs (close at red line) and after that the car developed the worst problem ever, an intermittent stalling problem - while driving on the highway at constant speed the car would just stall without any warning, like someone just turned off the ignition and it is not possible to get the car going anymore for at least a few hours. When the car cools, it always starts like nothing has happened. This problem is so annoying because always when I want to find the culprit, the car works, yesterday I did 300km (200 miles) and it died while going along in the city at slow speeds.
I started with changing the fuel filter, because I thought this was the problem, when nothing changed I did numerous tests with the fuel pressure o`meter, and came to the conclusion that there is no problem in the fuel system, fuel pressure regulator also works. When the problem occurs, there is no big change in the fuel pressure readings, so it makes me think that the problem is electrical.
Also I spent the last month to renew all the wiring harness, which I thought was the problem and it isn`t, because it didn`t change anything.
The only DTC is lean mixture lambda, because of an air leak from the idle valve, which makes the car run rough at idle, but I will change it when I get the valve from my mate.

What are your thoughts? Please feel free to ask any questions to better understand the problem.

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Jul 25^th, 2018, 5:41pm

Hi

Similar problems have been reported, you may find answers in earlier posts.

The 3 core shielded cable between the Edis & PCM can cause problems but I assume you've replaced it when you renewed the harness.
Not a solution, but sometimes with this type of thing disconnecting the battery for a few seconds may get it going again.
You could try swapping the engine management relay.

What code reader and software are you using?

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 25^th, 2018, 6:58pm

I have read all the threads I could find regarding 24v problems and nothing quite matches my case. I will try the battery removal and also change the relay

on 07/25/18 at 17:41:16, Tompion wrote:

Title: Re: 24V Cosworth mystic stalling problem
Post by Simmo on Jul 26^th, 2018, 9:07am

Before you do any more Clean the MAF (http://www.fordscorpio.co.uk/cleanmaf.htm). :)

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 26^th, 2018, 7:34pm

I have used some kind of BOSCH high tech service program and torque pro app on the phone.
Cleaning the MAF was the first thing to do, but that did no change a thing.
Can you elaborate on the "shielded" wires? Because they were regular wires before and I replaced them with regular ones as well.

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Jul 26^th, 2018, 9:27pm

If you go here & follow the link to the diagrams & download 2_9_24V_IGNITION.pdf:
http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=admin;action=display;num=1268901956

On the first page of the pdf you’ll see the wires to pins 1,3 & 4 of the EDIS module have a dotted circle around them signifying shielding.
On the 2.3 it’s in the loom that runs from the PCM in the passenger footwell, along the passenger side of the engine & across the front of the radiator to the EDIS – but whether the route on the 24v is the same I don’t know.
I can post a link later to the wire I used to replace mine.

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Jul 27^th, 2018, 7:11am

The wires to the crankshaft sensor should be twisted pair but what problems you might get with interference without the twist I don't know.

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 27^th, 2018, 8:09am

I will take a look at the loom in the front of the radiator, because I didn't do anything to it. Link for the shielded wire would be nice as well

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 27^th, 2018, 8:12am

The biggest problem is diagnosing the problem when it occurs, because if the car stalls, it could fire up after 5 mins or after 5hrs. I could check if there is power coming to the injectors, but they are not as easily accesible and they stop firing after 2 secs anyway. It is entirely possible that while I get to the injectors, the car has decieded to work and there will be power coming to the injectors.

Title: Re: 24V Cosworth mystic stalling problem
Post by PJDavis on Jul 27^th, 2018, 11:30pm

This is an electrical problem. Look at what was last done to the car and the area where it was done. Something has been disturbed, probably a wiring-loom or such. The wires are poor on this car, so look for this first. Is the left-side fuse-box free of water? Has it been removed, and not put back properly? Simple things, like has the battery got the proper cover on it? Look carefully through the forum for the probable signs.

But most important, keep telling us what you are doing to sort the problem, and if any of what we say helps, if you don't, we shall think you are fixed. If you keep posting with the problem, we shall keep trying to help.

Peter

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jul 28^th, 2018, 10:46am

So i checked the engine management relay, it is not to blame, because the car runs even when I remove it. Both fuses boxes look in too condition and they have all the covers. Also I replaced both crankshaft and camshaft sensors, nothing changed. Can somebody explain where can I find those 3 wires which go to the EDIS? I checked the loom in front of the radiator, I think it only consists of wires for the headlamps and the washers.

Title: Re: 24V Cosworth mystic stalling problem
Post by Pegasus on Jul 29^th, 2018, 9:25am

Similar happened to me 2 months ago - not at high speed but when I took foot off power when approaching junction. Car restarted straight away. Cleaned the Idle air control valve with carb cleaner and problem gone. This may not be the root cause of your problem but it's only a 10 minute job and may help anyway. Cleaning the MAF also recommended.

Out of interest, I did a search for new IACV for cosworths - seems they're no longer available (Ford or others)
:(

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Jul 30^th, 2018, 3:15am

The headlight wires run along the top. If you scroll down to the first picture on the right here you’ll see where the engine loom is at bumper level:
http://www.fordscorpio.co.uk/gearbox1.htm

It’s probably best not to disturb the loom unless you have to - you may have to replace the lot if it breaks up.
You can run the 3 core separately but of course it may not be your problem.
Can't say where the EDIS is on the 24v it's under the header tank on my 2.3, you can get the wire colours & pin numbers to look for from the pdf I linked to previously.
I used this wire I needed 3meters but it’s out of stock:
https://www.gps.co.uk/3-core-18-awg-screened-airframe-wire/p-0-1815/

They do a thinner gauge & I don’t think it matters for this but I wanted to use a similar size to the original.
There’s this on ebay but they don’t give the gauge:
https://www.ebay.co.uk/itm/202360847339

or this from brands hatch performance, I emailed and asked the gauge & temp rating but didn’t get a reply:
https://www.ebay.co.uk/itm/122746020961

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Aug 2^nd, 2018, 11:31pm

So I managed to get info about the shielded wires and where to get them, that is not a problem anymore. I was just reading this article : http://www.fordscorpio.co.uk/24vlooms.htm and the one thing which comes up all the time is that the Fuel Pump relay is giving signal to bunch of different things and I suspect, that maybe I need to investigate it a bit further.
In other news, I a different Idle speed valve, made a small difference. Drove for like 30 mins and then the car started to act up, first time I got it going by removing the battery for 2 mins, second time it also worked, but when it died the 3rd time I could not get it going. While my friend was towing me home I managed to start the car while being towed in neutral, very strange. Also I found a video of the car misfiring badly when the it starts to act up, will post a link tomorrow.

Title: Re: 24V Cosworth mystic stalling problem
Post by Nunnspoet on Aug 3^rd, 2018, 9:42am

Umm, a long shot: One of my Cosworths developed a stalling problem. it turned out to be the AC Pump stating to seize up. The engine would occasionally struggle whist waiting for traffic to move on. She would sometimes feel heavy on the throttle at different speeds etc. Try disconnecting the AC Pump belt and driving normally for some time. You never know, it might solve your problem.

Best regards and good luck

Mike :)

Title: Re: 24V Cosworth mystic stalling problem
Post by Scorpio_Mike on Aug 3^rd, 2018, 10:58am

on 08/03/18 at 09:42:39, Nunnspoet wrote:

A/C pump is driven off the serpentine belt which also drives the water pump, power steering & alternator.
find the relay in the auxiliary fuse box - that is the one on the passenger side next to the battery - and remove the A/C compressor relay which will stop the compressor clutch from engaging and the pulley should then just turn in idle mode.

Title: Re: 24V Cosworth mystic stalling problem
Post by Simmo on Aug 3^rd, 2018, 2:30pm

Mike, trying to add to your post I see that Fuse 35 is said to cover the Air Con Compressor whilst Relay 24 says Aircon.

:)

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Aug 3^rd, 2018, 4:50pm

The 24v has a separate belt for the aircon.

Title: Re: 24V Cosworth mystic stalling problem
Post by Simmo on Aug 3^rd, 2018, 8:32pm

Thank you Dave. ;)

Title: Re: 24V Cosworth mystic stalling problem
Post by a900one on Aug 3^rd, 2018, 9:00pm

My A/C belt only drives the compressor ???

Title: Re: 24V Cosworth mystic stalling problem
Post by Scorpio_Mike on Aug 3^rd, 2018, 9:33pm

on 08/03/18 at 16:50:39, Tompion wrote:

The 24v has a separate belt for the aircon.

I bow to your superior knowledge :-[

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on Aug 3^rd, 2018, 10:08pm

;D I thought it was the case - but had to look it up to check

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Apr 25^th, 2019, 9:38pm

Hey,

Some time has passed, but still there is no solution to this mystic problem. Just to be sure I replaced the fuel pump which was not the problem.
In my studies I have discovered, that when the car does not start, the injectors are not working, question is - why?
I have replaced fuel pump relays and it didn"t change anything, the relay itself is a 2 stage relay so I can't hot wire it to get past the relay, because I don't know which pin does what.
It was really strange that when I was measuring for voltage, there was voltage on the injector connector when the ignition was off, but the voltage was 6v.
Does 24V cosworth fire all the bank injectors at the same time? If so, could it be possible that a shorted injector is making the whole bank to not fire?
I have a donor car with a 24V cosworth PCM and PATS, if the problem is in the PCM, can I just replace the PCM and PATS for the car to fire up without problem? Or is some extra treatment needed?

Title: Re: 24V Cosworth mystic stalling problem
Post by Pianoman on May 15^th, 2019, 4:14pm

I had the same problem on my 24v. Engine would start and run perfect for around 5-10 min then die. If left for a while, it would start again. The problem turned out to be chaffed wires going into the ECU. Once I taped these with electrical tape, the car ran fine.

Title: Re: 24V Cosworth mystic stalling problem
Post by Tompion on May 16^th, 2019, 10:29pm

You can change the PCM, no need to change PATS. Presumably the dash light behaves as it should & doesn't flash a PATS code.

The injectors fire individually. When the ignition is on they all receive + V from a common splice via the Violet plus trace side of their plugs as does the idle speed control valve which is also is connected to this splice. The PCM controls the negative side via the Black plus trace wires.
The PCM pins used for injectors are listed here:
http://www.fordscorpio.co.uk/24vlooms.htm

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Jan 6^th, 2020, 8:47am

Hi guys, there has been some movement in this case.

Over the winter holidays I had spare time to spend with my troubled scorpio, it had been standing outside for the best part of a year, but once I connected a battery it started right up and ran fine form almost an hour, when it again went back to the darkside with a no start.

I spent a lot of time with the wiring diagram and multimeter chasing major possibilities of the PCM not sending injectijon pulse to the injectors. I found that the PCM recieves all neccesery grounds and all battery + voltage, but in the end the injectors still don't open. The wiring harness to the injectors is new.

My question is - does someone know hoe does the PCM thinks? Obviously the PCM is not receiving some vital signal, but how do I find which signals are vital and which ones are not. I have good spark so it would mean that the PCM recieves all signals regarding vital sensors.

In order to find the missing signal I nees to find without which signal will shut down the injectors in the PCM.

The PCM is good, I have tried to change it with another one, same simptoms.

I can't scan codes, because the PCM is not connecting to the car.

Please help, if you can.

Regards

Title: Re: 24V Cosworth mystic stalling problem
Post by theogrenietis on Feb 10^th, 2020, 11:11am

The mystic problem is SOLVED. I went though the complete wiring diagram and found the problem on the EDIS comuninication with the PCM. It's a shielded wire and all 3 signal wires had NO insulation on the point were they enter the metal shield. Probably they were touching agaist each other in the shield as well.
While the problem is fixed, it is still a mistery how could the car constantly work when it was cold and never run when it was hot and it stalled for the first time.
If it wasn't for one user who said that EDIS could also STOP the injection, I would have never found the problem, because in the diagram a buch of things are connected to the PCM and there is no way of knowing which ones are critical.

Happy Scorpio'ing!!!

Title: Re: 24V Cosworth mystic stalling problem
Post by Nunnspoet on Feb 12^th, 2020, 8:50am

Wow, well done!

You were determined to get to the bottom of this most frustrating, annoying, back breaking problem, and now you have done it. You must be pretty pleased with yourself, and rightly so 8).

For well over a year my Cossie, Ruby, would not give me Cossie power. She was like a lame Duck, eventually my excellent local Garage sorted some of the wiring out and now Ruby is like a Spring Chicken, up and raring to go. Just driving (dribbling) along, I am constantly aware of the power under my right foot.

So, as you say "Happy Scorpio'ing!!!"

Mike ::) :o