HELP!!!!! Odd side of engine wont fire?

[N1CERB]

Hi Folks,

Seems that I have lost ignition to the odd side of my 4.2 AJP engine!

I have checked plugs and leads and they seem fine, also quite new. New coil fitted and swapped over for even side to make sure it was fine. Removed the 4 pin connector and previously have swapped these for new ones. I have put a tester to each of the 4 pins and get + live feed to all pins when ignition is switched on, I also checked the good even side and this was the same. SO that prooves to me that there is power to the wires.

I can start the car but only the even side fires up and gets hot virtually straight away. The odd side just stays cold and throws unburnt fuel out of the exhuast as well as some pressure from the cmpression at that side.

I have tried all sorts wthin my ability and just cant get the odd side to fire or run!!

All I can think of is if maybe the ECU is not sending the ground signal to pins 1 and 2 as it is supposed to. I dont know how I can test this??

I dont have anything to connect upto the ECU so cant run diagnostic. The nearest TVR perosn is JIm Gansby down in Auckland some 2.5 hours drive away (Yes I live in New Zealand) so am wondering if I went to a local electronics diagnostic general specialist is this something that a non TVR garage can look into?

Would anything else stop me from firing up? Lambda sensor for example?

Any other sugestions much appreciated please?

My brain hurts!!

Cheers
Dave...

[sunbeam alpine]

Sorry if it's a srupid suggestion (and I don't know whether it's possible), but have you tried swapping over the leads from the good side? I note you've already tried the coil.

[jamieduff1981]

Have you confirmed you're actually getting a spark on the odd bank? e.g. with a good old fashioned stroboscope as used to set ignition timing with points?

And a *really* stupid question, but I ask because I've done this - are the leads on to the correct coil pack terminals?

[N1CERB]

Cheers folks.

I am not getting a spark. Or at least dont belive I am as it makes no odds if leads are on or off. I dont belive I am getting any spark what so ever due to coils not sending one down the HT leads.

I have swapped over from one side to the other and still the even side ran and the odd side didnt.

[Tanguero]

N1CERB said:

Cheers folks.

I am not getting a spark. Or at least dont belive I am as it makes no odds if leads are on or off. I dont belive I am getting any spark what so ever due to coils not sending one down the HT leads.

I have swapped over from one side to the other and still the even side ran and the odd side didnt.

Given that starting point you need to progressively swap components. Next put everything back to its correct bank, verify it fires then swap just the coil. If that works then both coils are good and the problem is the wiring to the coil, if not then it is that coil.

If both coils work on the even bank then look to the wiring harness or ECU its self being the problem.

You also want to check for a spark on the Odd bank the old fashioned way by taking a plug out and resting it against the engine block then turning the engine over with the fuel pump relay removed. You can see for sure if you are getting a spark that way.

Edited by Tanguero on Wednesday 31st August 13:11

[ukkid35]

Worth adding one of these to your toolbox

http://www.ebay.co.uk/itm/121548515992

Diagnostics/MIL didn't show anything when one of my coil packs failed (to one cylinder only).

The leads are long enough to wire up a spare coil pack loose without actually fitting it.

I was able to pick up a spare from a dead Saxo in a scrapyard for €20 when I was at the Ring in April, probably much easier to find one wherever you are.

[N1CERB]

Thanks again.

I have tried 3 coils on the odd side now and nothing. Also tried one of them on the working even side it worked fine. So prooving it is not the coil itself.

I actually have one of those spark tools so will give that a try tonight just to proove to myself there is no spark. I will also lay plugs againstthe block and turn the engine over to double-double check.

As mentioned I get a live feed to all 4 of the pins on the idd side coil pack, but dont know how to check if it gets a griund feed as it is supposed to. I thought just fixing a circuit tester to these pins would see it flash between live and ground, but I saw nothing.

In my mind I have an ECU problem. But hoping it is still something simple!

I will have one last go at it tonight and then I will be forced to quit. I just hope that I can find someone that can look into the electronics side of things for me as there are no TVR specialist elctics people in the country!

Fingers crossed...

[Tanguero]

You wont see the drop to ground at the coil with a meter or circuit tester - it is far too brief and fast. Only an oscilloscope will pick it up.

Before assuming its an ECU problem, first check the coil wiring harness to the bad side coil very carefully especially the wires into connectors and anywhere it might be abraded or stretched.

[jamieduff1981]

It's either no spark at all, which isolates the problem to somewhere between ECU and the LT side of the wiring harness to the coil pack, or you are getting a spark but with the wrong timing.

[FarmyardPants]

Isn't there a loom connector in the region of the expansion tank?