HELP VR DIED COMPLETELY

[muppetlab 0]

Hi mate sorry you have problems. Basically if the crank sensor is duff you wont get any sparks so as you had sparks this morning perhaps rule that out. If yours is a dizzy engine, the coil should have 3 wires to it, one is the trigger from the ecu think its white. This won't pulse if the crank sensor is broken as the ecu won't be getting a signal to know when to fire. Pull the fuel pipe off the injector rail, turn on the ignition and check you get fuel out. It will be under pressure so be careful it does not spray in your face, least then you will know its not the pump. Pull the lead from the coil to dizzy and check for sparks. There are ways to check the coil but i can't remember the figures for resistance across the terminals. I would check the trigger wire for the coil first, if thats not working its probably either the crank sensor or ecu. Also check the ECU relay, and fuel pump relay, on the fuse box as they are a common fault and fairly cheap and easy to change. You should be able to hear/feel if they are switching when the ignition is switched on. The crank sensor can apparently sometimes collect metal particles which can mess the readings up but when i pull mine out it was okay, and even though it looked pretty knackered worked fine so i left it. I had running problems for a while including random cutting out which i think were signs of the coil on the way out. Good luck, if you have any other questions just ask and i will try and help.

[laneontour 0]

Hi,

 

Thank for your help. My Corrado VR6 is a March 1994 model with coil pack.

 

My Story so far:

Car stalled on idle a few times and just got it home by keeping the revs up. Now I get no spark at all, although every so often after a day or so of leaving it I get a spark for maybe 5-10 seconds but not firing. Then no further spark.

 

 

Here are some further notes:

 

1. Fuel tests

a) The fuel pump works fine, there is fuel pouring out at the injector rail!

b) The fuel filter is only 4 months old.

 

2. ECU

a) I have changed Relay 109 although the old one seemed OK (not smelling of burnt electrics!)

b) The ECU is about 2 years old

c) I cleaned out the leaves from under the bonnet and sprayed up the cables. I have cleaned the contacts on the ECU too.

 

3. Injector tests (only single injector harness checked so far)

a) I have 12V across the terminals when ignition is on.

b) I have not checked for pulses due to broken lamp tester.

c) Resistance across the terminals is infinity. It should be 15-21.5 ohms I believe. IS THIS THE PROBLEM?

 

4. Coil tests

a) Terminals 1-6, 3-4 and 2-5 all have resistance of about 3400 ohms. This is very slightly lower than the specified 3600-4400 ohm window. IS THIS A PROBLEM?

b) Resistance between terminal 1 and Earth of the coil harness is zero as required.

c) Voltage between terminals 1-5 is 12V with ignition turned on.

d) With ignition turned on, voltage across 2-5, 3-5 and 4-5 were all 12V (is this as expected?) When turning over, the DC voltage measured with a multimeter did drop a little as would be expected if pulses were happening but pulses could not be checked due to broken lamp tester.

 

5. Crank Sensor Tests

a) Resistance between terminals 1-2 is 480 ohms (within limits).

b) Resistance between terminals 2-3 and 1-3 is infinity as expected.

c) Resistance between terminal 3 and Earth is zero as expected.

d) Turning over whilst moving the sensor cable about to check for any cable corrosion problems did not cause and firing.

 

6. Immobilizer tests

a) This is a March 1994 VR6 so a factory fitted Thatcham alarm with rectangular key fob. No chipped key. I have no idea how to test or disengage the immobiliser.

 

So the main issue I have found is 3©. What could this be?

Can anyone tell me how to disengage or test the immobiliser?

Any other ideas?

 

Thank you.

[muppetlab 0]

Sorry i'm not familar with the coil pack version. Not sure how it triggers but i do recall they have problems with cracks. Unsure about the injectors, i had problems trying to work out if mine were okay and i think i gave up in the end as i had a headache trying to work out wether they should be live and when etc. I am not sure what you are saying but i would guess the immobiliser is deactivated with the central locking? Someone told me once they either work or not and rarely intermitently. You say you sometimes get a spark then nothing. This is your problem, or one of them. Like i say i'm not familiar with the coilpack but would say you need to check what ever triggers the coilpack to fire and the coilpack itself. Not sure if it uses a camshaft sensor to judge the right position to fire or not? Make sure all leads are in good order and spark plugs are clean and gapped properly. I did have running problems for a while but resetting the ecu by disconnecting the battery for around ten minutes and then reconnecting will reset the ecu, Especially important if things like maf and tps have been unplugged. Oh i assume you have checked all connections and plugs. I would concentrate on one area at a time i.e check for spark, and sort that then fuel, air etc... An engine needs fuel, air and a spark to run sensors like maf and tps will make it run like poo but generally it will run roughly. good luck,

[laneontour 0]

Thanks,

I have fuel to the injector manifold.

I made a mistake on the injector resistance as I measured it on the harness side rather than the injector size (oops!) I will try to redo that.

I have clened and sprayed every plug and cable I can find.

Camshaft is rotating on turning over

Sparking for a few seconds every so often does maybe rule out an issue with the immobiliser although I have heard they run for a bit then cut out?

I'll reset the ECU and check for pulses ths evening.

Maybe look out for an ECU on here just to rule that out...

Thanks

[muppetlab 0]

I would make sure you can get a good spark. Have you removed the coil pack? If its sparking a bit then maybe the ecu is okay? Does it spark a bit on all leads or just one or two? If you can borrow/buy a set of them spark plug testers that light up. I had to use two in a line to see them whilst turning the key but you can definitely see if its sparking or not then. You need to start at the beginning and work through everything. I.e Check ecu is gettig power, check camshaft sensor not knackered, check power to camshaft sensor, check power to coil pack, check trigger to coil pack, check output from coil pack to plugs. When my coil failed it did instantly. car died. About twenty people told me it would not be the coil, i like you suspected the alarm and pulled out all the fusebox and wiring etc and had a real headache. Then i went back to basics and started checking everything from scratch with a multimeter. Theres loads on this forum about what voltages should be found where and various sensor resistances. Dont just start replacing stuff as it will get expensive and second hand stuff is not guarenteed to work anyway. You need to find the problem by isolating the options. My bet would be coil pack or camshaft sensor. or wiring thereabouts. Let me know how you get on and if you fix it. cheers

[laneontour 0]

Ok Thanks,

I have checked most parts of the coil now as stated but will check pulses tonight. very resistance is correct on the crank sensor so I guess I could rule that out. If I get pulses then the loom to the coil is all OK. I have the correct resisatnces on the coil though so can I not presume it's working correctly?