Hi,
I have a 1988 sierra sapphire cosworth fitted with a Clifford concept 300 alarm.
I have been trying fix a electrical problem I have been having for a while now, basically the car runs for anywhere from 5 to 20 min then one of the ecu relays starts clicking on and off rapidly causing the car to stop running.
I have narrowed it down to one of the two relays that runs the engine (it runs the fuel pump, Amal valve, air bypass etc)
I'm not sure if it's the alarm/immobiliser that is causing the relay to go nuts.
I have changed the relays and fuses to no effect. I have done a lot of things with just no effect.
I could really do with some help thanks guys

 

remove the alarm/immobiliser-or at least the immobiliser part of it
you could do it temporarily but i wont go into the how to part on here...
you can re-fit if not the issue

 

The immobiliser is a pain to get to and I can't seem to see where it is cut into the ignition any hints on best way to remove it?

 

i"m sorry it would be irresponsible of me to give you instructions on how to do that-particularly with you being a new member...
however a clifford dealer or auto electrician would do it for you

i have lots clifford parts for sale too-mostly 650/intellestart and sensors etc

sorry if i cant be more helpful but i think you might see my point....

 

Fair enough, I have found the concept 300 wiring diagram, it just looks like I'm going to need to pull my dash out to get at it though.
Yet another nice day in the garage and not driving my car

 

Ok spent the morning disconnecting the two wires from the ignition and removing the immobiliser wires to the ignition, reconnected the wires to factory standard.
All this done and it still cut out after 5 min of running, so not the immobiliser then!
Anybody had any problems with ground feed from the ecu to the fuel and ignition relay?
Or does anyone have any other ideas?

 

when it cuts out does it immediately restart??
a lot of cossies have the fuel pump hardwired to the rear-using the original trigger to relay in the boot area-with an uprated cable to rear
another pest is the phase sensor in dizzy

 

Think I have sorted it, found a melted wire about 8" down from the ecu plug it's an earth but there are two and only one had melted, looks like it melted some time ago and exposed the copper, don't know how it would cause this problem, but I have taped it up and inspected the rest of the wires and all seems fine. The car is now running and doesn't seem to have the problem any more, but only time will tell.

 

glad you found it
and sorry about not disclosing the clifford info-but as the owner of a car fitted with one i"m sure you like it to always be where you left it...

 

It's back with vengeance I'm now sat 5 miles from home waiting for a tow, I think I'm going to rip out the ecu and loom and just replace the lot gurrr

 

next time it does it run a power cable straight to fuel pump and make sure it is earthed and runs-if that doesnt get it going you know its ignition based-do you check for fuel and spark when it breaks down?-carry a plug?

 

I did a power check on pin 85 and 86 on the ignition relay when when the problem comes on, and the switch power to the relay was flicking on and off with the ignition on.
As it's everything connected to that relay is flicking on and off I can't see how it can one of them causing the problem as it's the switch power that is going on and off and not just the individual component.
The engine was freshly built this winter, with new pretty much everything, it run for over 450 miles went for a tune at MSD but had a hole in the intercooler so couldn't do the full tune. The problem started on the way home and has been the bane of my life ever since.

 

relay will need both power and a good earth to switch-and be a good relay too of course
wee theads like this are a mine of info

https://www.google.co.uk/url?sa=t&rc...QlCkHc4pmLpcgg

 

I have tried both positive and the earth hard wiring them both separately, the positive side didn't make any difference. But the earth side seem to work that is when I found the bad wire, so that's why I thought it was the suspect looking wire and why when the car run thought I sorted it.
The earth on the throttle cable bracket looks good, and when the car was running yesterday it seemed to be running really good.
Think I'm going to take the car off the road this year and just pull the loom and replace the ecu with a aftermarket one when I can afford it

 

The relay you mention is the fuel pump relay, and sounds like it has a bad connection or the relay is bad!

One of the things you have completely overlooked is the relay, swap this with the ECU relay and see if the problem moves...

Applying power to the pump shows nothing!

Martin

 

I have replaced both relays sorry for not mentioning it, I have done so much you would not belive, I did not the pump but the switch side of the relay, as it was switching on and off thought the switch side.
And swapped them after replacing them

 

Also when the problem starts I also pulled the relay power (20a) fuse while it was clicking on and off and it carried on clicking which led me to belive it was something connected to the switch side of the relay (pin 85 and 86)
According to my wiring diagram that relay not only powers the fuel pump but also powers the air buypass and Amal valve too, which I have check and is.

 

One thing I have noticed is that when holding ignition on (not starting) the fuel pump relay stays on and does not just prime then turn off.

What would cause this?

 

You could have a bad supply to the relay.

What you could do as a test is bridge pin 30 and 85 and see if the relay closes?

Yes on 2WD, it powers what you say.

Martin

 

~Multiplug above the ecu can play havoc . Hard wired mine in the end .

 

Not sure what plug you are referring to, above the ECU?

 

Yes where the main wires come from the ignition area over toward ecu, there is a connector there. My car kept cutting out here and there and eventually refused to start, It was the plug i mention.