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        General >> Problems >> Cosworth wont start
        
(Message started by: pyramidls on Apr 29^th, 2021, 9:57am)

Title: Cosworth wont start
Post by pyramidls on Apr 29^th, 2021, 9:57am

Hello Everyone,

I've recently bought a 1995 Scorpio Cosworth which wont start.
I discovered that the engine management fuse (f37) had blown and kept blowing when replaced. I traced this back to a chafing wire, fixed it and the fuse is ok now.

When you turn the key to position 2, the lights on the dash come on but the fuel pump isnt running. I have tested the fuel pump relay and this seems to be working correctly. It appears that the 2nd relay in the fuel pump relay isnt getting triggered by the PCM. I wonder if it is PATS related, although the pats light isnt on and no pats code is generated to indicate any form of immobilisation.
When you turn the key to position 3 nothing happens, no starter etc.

Has anyone any idea what this is and what to look at?

I would be grateful for any help with this matter.

Thanks

Neil

Title: Re: Cosworth wont start
Post by Torbayboy on Apr 29^th, 2021, 12:45pm

I know this sounds basic and I dont wanna insult you, but you have checked the trip switch for the fuel pump in the boot (car) or side by rear lights (estate), sometimes just a gentle knock sets them off

Title: Re: Cosworth wont start
Post by Tompion on Apr 29^th, 2021, 1:45pm

What does the PATS light do? When you turn the ignition on it should light then go out. In daylight it can be difficult to see - I can only just about see it with my hand shielding it from daylight.

If it is lighting & going out it can be a problem in the wiring between the EDIS & the PCM. If the PCM doesn't get a good signal it won't power the fuel pump relay. Some people including me have had to replace the shielded 3 core cable.

Having said that I think the pump should still run for a few seconds (if the PATS light lights and goes out) as normal when you turn on the ignition - you can normally hear it run but you may need to be at the back of the car to hear it.

Dave

Title: Re: Cosworth wont start
Post by Snoopy on Apr 30^th, 2021, 8:39am

There is a way of by passing the PATS. IF you want to try that email me and I will send you how to do it.

Title: Re: Cosworth wont start
Post by PJDavis on Apr 30^th, 2021, 5:31pm

on 04/29/21 at 12:45:30, Torbayboy wrote:

Well, Neil asked me about this a couple of days ago, and I gave him a couple of suggestions, but I forgot about the 'trip-switch'!! Jags don't have them! So Roy, good Man!

Title: Re: Cosworth wont start
Post by pyramidls on Apr 30^th, 2021, 7:57pm

Thanks for the suggestions.
The fuel cut off switch is down.
The pats light does light then goes off.

I'll have a better look at the EDIS connector when I next get a chance, I think the wiring on it is a bit poor. How easy is it to replace the wiring? Is the connector easy to rewire?

Thanks

Neil

Title: Re: Cosworth wont start
Post by Tompion on May 1^st, 2021, 3:51pm

My experiance is with the 4 cyliner but I believe EDIS-6 on the coswoth is the same but different keyway. In fact I used a an EDIS-6 plug and cut the keyway off - just reluctant to say for certain when I've had no dealings with a Cosworth & their are different types of plugs, but fairly sure your's is the same type :)

The plugs come apart fairly easily but can be brittle, quite likely the locating clip to the EDIS will break. Trouble is you can't get the terminals or at least I couldn't find any.

It was possible to buy the plug with pigtails, which is what I used but would have preferred terminals for crimping.

On another car I cut the wires a few inches long removed the crumbling insulation & shrunk on some heat sleeve over the wire and the crimp of the terminal - think I added a second layer of heatshrink then crimped or soldered to the new loom. Another way I've done it is to spring open the crimp for the insulation, flex the strands where they are crimped untill they break off then crimp the the new wire insulation back & solder the wire on top of the wire crimp - it is possible to open the wire crimp but a bit of a struggle and more chance of it breaking hence I soldered it, but you need to make sure it's not to fat to go back in the plug.

The plug I used was an AIRTEX/WELLS 1P1092 from Rockauto but it's out of stock:
https://www.rockauto.com/en/parts/wve,1P1092,ignition+control+module+(icm)+connector,10623

This looks to be right & lists 1P1092 as an equivelant - check the keyway compared to yours:
https://www.ebay.com/itm/284148711144

Try & get duty paid it can be quite costly otherwise.

You can always try & get one from a scrappie to play with.

Title: Re: Cosworth wont start
Post by pyramidls on May 1^st, 2021, 4:06pm

Hi Dave,

So you didn't run a new screened cable back to the PCM, you just replaced the connector and the first few inches of wire?

Neil

Title: Re: Cosworth wont start
Post by Tompion on May 1^st, 2021, 4:35pm

I replaced all the wires to the EDIS including the shielded ones, but I had to do all the engine bay loom:
http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=news;action=display;num=1522303878

If you need to get at the PCM you may find this useful, although about the fans there are details for getting the PCM out:
http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=admin;action=display;num=1536026659

Title: Re: Cosworth wont start
Post by Tompion on May 1^st, 2021, 7:53pm

Takes a while to dredge things up from my mind :(
When you turn on the ignition the pump runs for a short period to pressurise the system, if the engine doesn't run the relay shuts it off.
If you can't hear the pump you can test if it did run/pressurise by pushing in the test valve on the injector rail. I usually put a bit of rag round it to soak up the petrol but it's normally only a small amount.

If there is a problem with the ignition signal such as the shielded cable failing (outside acceptable limits) then the PCM won't fire the injectors. You may find putting a teaspoon of petrol into the inlet manifold will get it to fire briefly which would suggest injectors not firing but that would depend on how serious the problem is with the ignition signal - assuming that's the fault.

Always worth checking for codes with OBD.

Title: Re: Cosworth wont start
Post by PJDavis on May 2^nd, 2021, 6:49pm

Aha! As soon as anyone talks about the wiring being suspect..................what do we all start to think? Brittle wiring, fuel shut off loom, MAF sensors. These engine compartments get very hot, I replaced lots of brittle wires, hours spent, all of what Dave says is applicable, but I wonder, and might even bet on brittle wires!

Title: Re: Cosworth wont start
Post by pyramidls on May 5^th, 2021, 7:08pm

I managed to look a the edis connector and wiring this afternoon. Although the insulation is in quite a poor state, there is continuity on all conductors and more importantly no shorts, especially on the shielded cable. So I would think that this is ok, I just need to repair the insulation or replace the end of the cable.
I dont think that this is causing the non starting issue. We are not getting as far as the injectors as the starter motor isnt even turn over.
I need to try and check the fuel pump again but I'm pretty sure that the PCM isnt triggering it.

Title: Re: Cosworth wont start
Post by Tompion on May 6^th, 2021, 10:53pm

Sorry got side tracked with you mentioning the fuel pump first, hadn't noticed the "no starter".

Have you checked if there's a problem with the start inhibitor relay - possibly a problem with the gear selector, try starting in neutral if you’ve only tried in park.

Title: Re: Cosworth wont start
Post by Nunnspoet on May 10^th, 2021, 7:01am

Dinosaurus par excellent here (ask my family). Give the starter motor a sharp tap with a hammer. Takes a couple of mins. and no harm done.

Mike :) :)

Title: Re: Cosworth wont start
Post by a900one on May 10^th, 2021, 10:44am

Hi Mike
I have sent you a PM.
Gerald.

Title: Re: Cosworth wont start
Post by Nunnspoet on May 10^th, 2021, 7:04pm

Can't find it Gerald ???
Busting with curiosity
Mike

Title: Re: Cosworth wont start
Post by a900one on May 10^th, 2021, 11:02pm

Hi Mike
I have tried again 8)

Title: Re: Cosworth wont start
Post by Jackattack2002 on May 11^th, 2021, 7:34pm

My 24V does this too, but only when hot. The engine is completely dead - no clicks and the starter doesn't try to engage. I have replaced the Transmission Gear Sensor and other related stuff, but to no avail. I am convinced it's PATS related and not providing an earth path for the starter cct. Check the whole starter & inhibitor cct. There is a small chance it's starter motor related i.e. the solenoid is sticking and not engaging. I have never been able to pin-point my issue, as the engine is too hot when the gremlin appears

Title: Re: Cosworth wont start
Post by pyramidls on May 19^th, 2021, 9:41pm

Ive now repaired the insulation on the Edis connector.
I tried starting in Neutral and Park without success. When you move the gear selector up and down you can hear something happening.
I tried bypassing the start inhibit relay and the starter motor did crank but the battery was too flat to turn over properly. I have put the battery on charge overnight so will try again tommorrow. It will be interesting to see whether it will fire or just crank.
Snoopy-can you tell me how to bypass PATS so I can see if that is responsible. As PATS seems to supply the earth for various things including the fuel pump relay and start inhibit relay/starter motor, it must be a probable suspect.

Title: Re: Cosworth wont start
Post by Snoopy on May 20^th, 2021, 6:35am

I will send you the details in a Private Message.
Snoopy

Title: Re: Cosworth wont start
Post by pyramidls on May 23^rd, 2021, 11:36am

I had it turning over but it wouldnt fire.
I checked the contacts on the fuel cut off switch, which didnt seem to have continuity between NC and Common. I removed the switch and linked the wires together. With the ignition at position 2, I had 12v at the switch, which indicated a fuel pump problem.
I dropped the tank, which was a pain due to rusty strap bolts. The fuel pipes were a nightmare to get off and the white and red clips broke off, but I managed to get them out eventually. I took the pump/sender unit out and it was in quite a poor state. Inside the tank looked quite brown, so I may have to replace the tank. I checked that there was 12v at the fuel pump connector, which there was, so the pump must have gone. I've ordered another one, so hopefully that will solve it.
Does anyone know where I can get the red and white fuel pipe clips (locking collar) that broke off? They look the same on several other Ford pump/sender units, so I might just have to get a used one and the the bits off. Also should the fuel gauge work in position 2? That was also in quite a state but I've cleaned it up and the resistance is now changing as it is moved up and down. I need to check whether it is showing on the dash.
Hopefully making slow progress, but Ford haven't made things easy!

Title: Re: Cosworth wont start
Post by pyramidls on Jun 5^th, 2021, 1:54pm

Quick update.
Ive replaced the tank and pump, which is now working and checked that there is a spark on the plugs which there is.
It now fires up, but sounds awful. I think it may only be running on a reduced number of cylinders. You have to keep you foot on the accelerator to keep it going otherwise it cuts out. I am wondering whether this could be an injector problem. So although the spark is there, one or more cylinders has no fuel going into it.
I think the fact that it does start, albeit very roughly eliminates any PATS problem and know we are looking at the injectors. I need to find out whether all the injectors are working correctly.

Title: Re: Cosworth wont start
Post by amigafan2003 on Jun 5^th, 2021, 6:14pm

Pull all the plugs, crank it over for a while, looks into each plug hole to confirm there is fuel for each cylinder.

Title: Re: Cosworth wont start
Post by pyramidls on Jun 7^th, 2021, 6:20pm

I pulled all the plugs, which were all black, but I couldnt see any sign of fuel or smell any. I checked the valve on the fuel line and there is fuel there. Its strange that there is no fuel at any cylinder. Could it be fuel pressure regulator or the injectors or something else?

Title: Re: Cosworth wont start
Post by pyramidls on Jun 9^th, 2021, 4:48pm

Ive checked again now and there is fuel at each cylinder. So we have a spark and we have fuel but it still sounds like its misfiring ( terrible). What would cause this? Is it timing related or something else?

Title: Re: Cosworth wont start
Post by Snoopy on Jun 10^th, 2021, 8:34am

It takes time to learn. there is a special drive cycle to improve driveabilty [HERE] (http://fordscorpio.co.uk/idleprob.htm) and at the bottom of this page THIS ONE (http://fordscorpio.co.uk/obd2scan9.htm)

Title: Re: Cosworth wont start
Post by Jackattack2002 on Jun 20^th, 2021, 12:13pm

A common fault is the twin-connector in the engine-bay, close to the battery. One of the wires (grey) forms the latter part of the starting-loom and eventually connects to the solenoid. This connector is prone to corrosion and exhaust-heat exposure. If the connector block is still correctly mounted, it should be attached to the body just above the fuel lines. If the mounting-clip has sheered, it may be just hanging loose.

Title: Re: Cosworth wont start
Post by Jackattack2002 on Jun 20^th, 2021, 12:32pm

As the fuel supply is fed through a common rail, any cylinder starvation can only be attributed to a failed (or blocked) injector, or a fault in the wiring loom connecting to that specific injector(s).

Title: Re: Cosworth wont start
Post by pyramidls on Jul 12^th, 2021, 7:50pm

Have now got it running roughly. Whilst trying to figure what's happening, I noticed that the passenger side cat was glowing red hot, which obviously isn't good. I know that this could be caused by a misfire, which may explain the poor running and sounding like its not running on all cylinders. There is a spark at each cylinder.
Has anyone had any experience of this?
I think I need to get it scanned to see if there are any fault codes.

Title: Re: Cosworth wont start
Post by Tompion on Jul 13^th, 2021, 11:15am

Crossed HT leads could cause a hot cat - unburnt fuel igniting in the cat.
I beleve the pairs should be 1&5 2&6 3&4
Looking at the coil pack:
123
564