Help troubleshooting ignition problems

[Grant]

Finally got my AB cables installed last week. They are great by the way. Unfortunately I now have new problems. Took the élan out for a spin last week and it ran like a champ, but that was short lived. It ran for about a half hour then I parked for about an hour and when I came back she started right up, but after about 100 yards of driving it suddenly dropped to 2 cylinders.

I have replaced both ignition coils (MSD 8224) and installed all new plugs (NGK BKR6EIX and gapped to .8mm). I did not replace leads (Kingsborne) but all tested OK. After all this, I still seem to be running on the same 2 cylinders (But I must admit it is running better on just 2 than previously). From what I can tell cylinders 2 and 4 are out. Removing the leads from these 2 had no effect on the engine. Any ideas where to go from here? Injectors maybe? Any other things I should check?

Thanks all!
Grant

[paza1]

Hi Grant,
Have you any fault codes?
Do you get the engine light on?
You mention you have changed the coils...might be worth checking the earth connection is isolated from the baseplate with a plastic washer...easily missed
Try swapping the leads over to see if the fault moves cylinders

Good luck
Mark

[Grant]

No check engine light, except briefly when trying to limp home on 2 cylinders at high RPMs. Haven't checked fault codes yet, but will do that as soon as I have a chance. don't have a tool so I guess I will have to try the paper clip method. I just removed the coil packs from the base by removing the 4 small screws, instead of removing the bolts holding the bracket to the fender wall. The earth is connected to the mounting bracket right?

Thanks!

[router]

Grant,

Youre right the earth is connected to the mounting bracket. Replacing the coils the way you have wouldnt had disturbed the earth connection.

Neil

[Sy V]

What's the connection like from the coil pack to mounting bracket?
Is that clean?
I know the packs are numbered, but surely they're interchangeable to test if one side is defunct?

Just throwing ideas in... anyone who knows me will confirm that wiggly-amps ain't my metier.

[ailwyn]

Grant,

Have you checked to see if the plugs in 2 & 4 are wet? this should rule out a fuel related issue.

If you can't tell, then as Sy said, try swapping the coils, they are the same except for the numbers on the top, just make sure you wire the opposite cylinders to those indicated on the top of the coil. Because of the "wasted spark" it's the pairings that matter, not the exact wire location.

Ailwyn

[Grant]

I'm pretty sure it not coil related as I just replaced them, but also it is cylinder 2 and 4 that are out. 1 and 3 work, and they are on different coils. But I'll try swapping just to be sure. Also, tried to find the ALDL plug last night to check for error codes but could not find it. It is supposed to be under the passenger side dash right? Is the plug mounted to something or should I just be looking for a dangling wire?

[al]

Yep, swing the glove compartment all the way out so it's hanging upside down, and you'll find the ALDL connector through the hole where the glove compartment used to be: it'll be at the back plugged into a empty holding socket - looks like this:
http://wikilec.9600.org/images/8/86/ALD ... Photo1.jpg

[Gaz]

Hi Grant,

Why don't you find a reliable workshop who knows how to use an oscilloscope and pay for an hour of their time. This way you can be sure of where the problem originates from ie fuel or ignition problem and also have a 4 gas analysis carried out. That in itself can tell you lot's. You really need to do this first instead of having a stab in the dark. Do that, then post the results and I'll see if I can help further.

Regards

Gaz

[GeoffSmith]

The injectors are common as well..... 1&3, 2&4.

wikilec.9600.org/images/1/1e/MJ25-04_Engine_Management_(Turbo).gif

[Gaz]

The injectors are common as well..... 1&3, 2&4.

wikilec.9600.org/images/1/1e/MJ25-04_Engine_Management_(Turbo).gif

Looks like the earth return for injectors 2 and 4 go back to terminal D15 on ecu, from there they are switch on by ecu. Assuming ecu is OK I would be checking the wiring from the 2 suspect injectors back to that terminal. However, as said earlier, an oscilloscope checking volts and amps at injectors will confirm 100% if they are being switched on and off.

[Grant]

Thanks all! I will check error codes tonight now that I know where the AlDl is, and if that doesn't tell me anything, it maybe time to head off to the shop to put her on the scope.

[Grant]

Last night I tried to ground the ALDL to put in to diagnostic mode. With the ignition on but engine off I grounded the ALDL with a paper clip but nothing happened. No flashing of the check engine light. Am I doing this corectly? See picture.

ALDL.JPG

[Monty]

Can`t see the wires in your photo, it should be the black and white wires

[addict]

i also have a no spark problem and no fault codes using the paper clip
eg no spark
will check the cut out switch

[addict]

i have founnd this and cant see where it goes

[addict]

these go some where also

[CJ101KT]

I had a problem in one instance where the car was running very rough after being sat in the NEC for four days. Turned out that one of the injectors was dirty and once cleaned it ran perfect again. Maybe something to get looked at by someone mobile if you have anyone in the area good at that sort of thing? Just saying this as the injector problem didn't cause an engine management light.

[addict]

these fit together but look like they never have been.

defo no spark at the plugs

[Enright]

This is like that game where you see a photo of something from an odd (or in this case really close up) angle and have to guess what it is!

It looks like each of these pics has been taken around the air filter "dustbin" area.

I'm not too sure about the first one - will have to check.
In the second pic they look like vacuum pipes, of the same sort that go to the back of the heater control. Can you trace where the other ends come from?
I don't think the third ones are important - I'm pretty sure that we all have them as part of the generic loom.

Do you have an aftermarket alarm/immobiliser fitted? It could be disrupting the signal. The cut off switch which I think you might have been referring to before (next to the battery) just cuts the feed to the fuel pump. It doesn't have anything to do with the ignition system.

Hope that helps.