Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Lefty]

Hi guys, originally posted this problem under "Swapping ECU's", but having investigated further, felt a different title more relevant.
   Problem is my '94 2.5 V6 (119K miles) will not fire up. I had just renewed plugs and cam cover gasket on LH bank, started her up, and after a few moments she cut out and wouldn't restart. No flashing engine light. Codes stored were imob 144 and 145, but I suspect this maybe a red herring as signal from imob/antitheft to pin 27 of ECU is good (+12v). First thing I noticed was the fuel pump does't run. Checked ECU signal (pin 3) that picks pump relay and it's +12v, but should go to 0v to turn on pump ... sounds dodgy I thought. Other observations: when cranking, the engine light doesn't flash but goes out after couple of seconds (looking good), and, using a hand held scope, was able to see that all injectors were firing, camshaft and crankshaft sensors giving convincing outputs, and dis pack primaries appeared to be fired correctly. But using a spare spark plug connected to plug leads on RH bank, no evidence of sparking at all. Ah ha! ... looks like a dead dis pack I'm thinking. Now before I go shredding my hands and temper in replacing it, can anybody explain the fuel pump issue? Does any know if the pump should turn on with ignition, or does it only turn on when engine rotation is sensed? I'd hate to go through the dis pack swap for nothing! Sorry if I've gone on a bit, but this problem is getting to me, so any help will be appreciated.

Cheers,  Lefty

[RobG]

Dodgy crank sensor will give no spark and no fuel

[Kevin Wood]

I have a feeling the fuel pump will only run when cranking is detected on this system. I don't think it even runs for priming when the ignition is turned on.

If you remove the fuel pump relay and bridge the two contacts with a short wire link with two spade connectors on, you can test the fuel pump. You could also try cracking open the feed connection union from flexible pipe to fuel rail on the driver's side and see if you have pressure there.

There is a fuel pump fuse in the fusebox in the driver's footwell.

If you have pulses at the injector and coil primary wiring it suggests that a crank signal is being picked up by the crank sensor although the lack of a spark is a concern.

Kevin

[Lefty]

Thanks for that info Kevin. I've already established that the pump works fine, (a jumper from ECU pin 3 to pin 2, one of the ground pins, will pick the pump relay. (Thank heavens for my Haynes manual schematics)) but realised as I was typing up my post that I hadn't checked if the pump powered up whilst cranking. I'll check it first thing tomorrow. I guess if it does, things start to look gloomy for the dis pack! (and for my knuckles, hands, back, legs, and every thing else...).

Lefty

[Lefty]

Have now verified that my fuel pump relay is only picked when engine is rotating! This must be worth noting for anybody trying to trouble shoot fuel pump problems. As every thing else now apparently eliminated, proceeded with dis pack removal ... that is one nasty job! Found one of the hardest parts was actually pulling off the lower plug leads. Just not enough strength in my poor old fingers to yank them out, so made up a simple tool out of a piece of 5mm thick plastic, cut to approx 5cm/2" square with a "U" shaped cutout on one side. Manouvre it with fingers to slip under the rubber boot of the plug lead and gently lever up. A couple of jiggles (!) and off pops the lead. Slightly reassured to find the pack in a fairly naff state of decay. So new one winging it's way as I type. Fingers crossed that that is the cure, or it could be time for the Great Garage in the Sky for the old girl..

Lefty

[PhilRich]

Fingers & everything else crossed for you here Lefty, Good Luck with it! 

[Andy H]

Have now verified that my fuel pump relay is only picked when engine is rotating! This must be worth noting for anybody trying to trouble shoot fuel pump problems. As every thing else now apparently eliminated, proceeded with dis pack removal ... that is one nasty job! Found one of the hardest parts was actually pulling off the lower plug leads. Just not enough strength in my poor old fingers to yank them out, so made up a simple tool out of a piece of 5mm thick plastic, cut to approx 5cm/2" square with a "U" shaped cutout on one side. Manouvre it with fingers to slip under the rubber boot of the plug lead and gently lever up. A couple of jiggles (!) and off pops the lead. Slightly reassured to find the pack in a fairly naff state of decay. So new one winging it's way as I type. Fingers crossed that that is the cure, or it could be time for the Great Garage in the Sky for the old girl..

Lefty

IIRC the standard plug leads have a bright yellow clip attached to one of plug caps. Pull it off and it reveals itself to be a tool for pulling plug leads with.

[Andy B]

......
IIRC the standard plug leads have a bright yellow clip attached to one of plug caps. Pull it off and it reveals itself to be a tool for pulling plug leads with.

Mine's a dirty red/brown colour ...... I think  :-/

[Lefty]

Evenin' all,
New dis pack arrived this morning, installed and delighted to report she started on the button!

Would just like to thank those who offered advice, and to Kevin in particular for his valuable contribution;

I have a feeling the fuel pump will only run when cranking is detected on this system. I don't think it even runs for priming when the ignition is turned on. Kevin

Perhaps I can now get back to living, and maybe concentrate on some of the more mundane niggles with the car.

Lefty

[Hannah Judes Dad]

Evenin' all,
New dis pack arrived this morning, installed and delighted to report she started on the button!

Would just like to thank those who offered advice, and to Kevin in particular for his valuable contribution;

I have a feeling the fuel pump will only run when cranking is detected on this system. I don't think it even runs for priming when the ignition is turned on. Kevin

Perhaps I can now get back to living, and maybe concentrate on some of the more mundane niggles with the car.
Lefty

How long have you got ?