Any ideas why my car now won't fire up.

Post by **Ben** » Sat Dec 23, 2006 11:20 am

Well, started to notice a slight missfire at about 5000 - so believing it was the same as when I first got the car decided to swap out the plugs.

Stripped it down, replaced plugs, checked all the coil packs, put it back to together and went for a test run. Initially felt fine but then could still feel it hesistating a tiny amount.

Drove around for a while, parked up - when I went to restart it would turnover but not fire up. Fuel pump priming but no spark. Got the RAC out, he checked earth and all looked ok. He plugged a booster in and the car fired up.

turned off and on and off and on - then it wouldn't fire up again - connected the booster got it running again. He noted that there was a massive power drain on the battery when he went to start it.

So we got it running and I decided to get it home and worry about the problem later. Drove it for about 10 miles, suddenly could feel that it was struggling, pulled up at traffic lights and the car died. Magically for me, the RAC was a few cars behind and pulled over with me. This time he couldn't get it running for love nor money so it was time for a ride home on a low loader.

Basic guess was that the ignition amp had failed, so sourced myself a second hand one - however exactly the same symptoms. Turn key, pump primes, turn it over, it acts like it wants to go, but just won't hold and run.

Anyone got a suggestion as to what maybe the problem, I'm assuming that when i was changing the plugs I may have disturbed something, what, I do not know. I've bought a grounding kit and will fit that shortly to remove any chance that it's a poor earth. Going to also order some Splitfires and fit though anyway.

cheers

Ben

Bladerider · Post by **Bladerider** » Sat Dec 23, 2006 11:38 am

How did you test your coilpacks ??

Do you know 100% that the amp you got was working perfectly before ??

Have you check the control wires to your amp from the ecu ??

Have you checked the earth for the ecu ??

This may sound stupid, but have you checked you have no major blown fuses, as the car could still be getting power from somewhere else its not meant to even if a main (ecu control for example) fuse has died. You wouldnt believe how difficult it was to stop the orange from running with the battery kill switch - hence why I ask !!!

Have you asked the car if its just on a strop 'cos its bored of being driven so slowly ??? :P :P

Nik · Post by **Nik** » Sat Dec 23, 2006 11:53 am

Sounds like it is something electrical for sure. Might even be a wire shorting somewhere. I had that on a car before where it would be fine when cold, but when it warmed up it would flood itself and die. It turned out to be the wire from the ECU chaffing on the block when it was hot and shorting out.

I could be completely wrong though but it is just a thought.

ants13 · Post by **ants13** » Sat Dec 23, 2006 1:23 pm

Had a similar problem on my S13.
Wouldnt run right, wouldnt start etc. Turned out to be a dodgy connection on the battery earth. It's gotta be worth checking.

Post by **Ben** » Sat Dec 23, 2006 3:29 pm

ROFL at bladey, thanks for the feedback boys - I've checked the fuses - all the ones under the dash and the ones in the engine bay - all look ok. I'm going to fit a new grounding kit to make sure that all the earths are covered.

Going to fit a new battery as the test device showed that it wasn't 100%.
And with regards the Coil packs I only gave them a visual check - if one was duff - surely the others would still fire the car up?.

slaphead · Post by **slaphead** » Sat Dec 23, 2006 8:09 pm

I was kind of expecting this thread to appear after the breakdown returning from Snetterton Ben

OK - I'll put my Tech Support hat on :lol:

You were trying to cure a 5K misfire as I recall at snetterton - ?

Do you think that the problem you have now is the same issue (just worse)

If so it would seem highly likely that one or more the coil packs could be at fault - this would have potential to cause a fairly high drain on the ignition circuit dragging down the output from a common rail power source feeding all the coil packs

I would therefore suggest that the coil pack pairs were disconnected one at a time and the car tested to see if it fires up - therefore narrowing down the fault finding process.

or

Do you feel that this is another problem entirely

Given that you were pulling plugs out - this entailed the repeated removal of the coil pack pairs - therefore the chances of damaging the wiring whilst doing so is fairly high - especially as the wiring in question is exposed to extreme heat ranges and therefore over the years becomes extremely brittle and liable to snapping

The test above may help here - as long as any breakages are below the common rail i.e. between coil pack and connector

or completely out of left field - the only thing that has stopped mine dead is the AFM wiring - wire four on the top afm to be precise - this pretty much killed the car dead - would not start - the test for this is disconnect the top afm and see if it goes bang

Sorry if this teaching granny to suck eggs :oops:

~Mark

323ian · Post by **323ian** » Sat Dec 23, 2006 8:15 pm

Ben your earth kit will not rule out a bad earth.
Check the negative cable from the battery for a start.
Could be a faulty ECU earth.
Symptoms really point to coil packs breaking down though.

Post by **Ben** » Sat Dec 23, 2006 8:38 pm

Very interesting boys, I'm defintiely buying a new set of coil packs anyway. How do i go about checking the earth to the ECU then, I remember thinking that the wire the runs into the coils was quite a tight fit when I was putting the cover back over.

Problem with the wiring is that they all have that horrid brittle wrap on so I can't check them - as in all the wires are protected by a shrouding.

Bladerider · Post by **Bladerider** » Sat Dec 23, 2006 10:15 pm

Easiest way to check the earth to the ecu is to run a new one.

If it works then you have found the problem, simply bolt and earth wire to the casing and to the door hinge or similar.

I still think this sounds like coilpacks, running rough at revs, dropping to running rough everywhere, dropping to not running at all - the afm wire would just kill it dead as the ecu wouldnt have any gauge of what was going on.

I have a feeling there is a little earth wire on the back of the ignition amp that gets very brittle, but this is really searching the darker reaches of what little grey matter i have left !!!

Oh and you didnt tell us what the car said when you talked about your driving !!!

Post by **Ben** » Sat Dec 23, 2006 10:38 pm

Bladey - what on earth does this mean? "Oh and you didnt tell us what the car said when you talked about your driving !!! "

And the car isn't running at all! - no revs at all