Thread: Another ignition module failure?

Sounds a bit like an issue I had on a '97 D1 3.9, would start OK, running a bit rich, then when it got near normal running temperature it was like it dropped a few cylinders and would backfire under load.
Turned out to be a crook engine coolant temperature sender unit, the one that communicates with the ECU.
If you do replace it get the Britpart one, not the Lucas, the difference is that on the Britpart the socket goes onto metal whereas on the Lucas it goes onto plastic and of late there has been a faulty batch where the plastic spins on the metal sender unit and you cannot tension up the unit into the thread in the inlet manifold.
Sender unit is only about $20, so hope this helps.
Lee

Maybe a Bosch CTS would be better........

Hi bee utey,
After cold start all plugs are clean and always have been. I will have to get hold of some gear (not at home) and start pulling and testing sensors etc.
Bloody annoying!!!

Pretty sure it will be electrical as when it "went rough" on the road it came good "instantly" after a while then "went rough" again after several km. Needless to say I am cleaning every ground point I can find and also have additional earth cables from rear of block and coil mount ground to battery ground (put those on when I got the car a couple of years ago).

You may even find it's dry/cracked solder joints on the ECU circuit board.

May be worth getting it checked/refurbed at a place like Logicar/Petroject.
Or if your handy with a soldering iron.........

Hi Guys,
Had a chance to do some more troubleshooting....Fuel pressure tests at 30psi. This is lower than the 34 - 38psi spec, however the gauge is uncalibrated, so could read high or low. After shutoff the pressure holds rock steady for an hour at 30psi indicated, dropping to 29 after 90mins. As a result, I think the fuel pump can be ruled out as a cause.

Have tried a new Bosch blue dizzy cap (only one I could get easily) and no difference.

The adventure continues...

Originally Posted by 83rangie

You may even find it's dry/cracked solder joints on the ECU circuit board.

May be worth getting it checked/refurbed at a place like Logicar/Petroject.
Or if your handy with a soldering iron.........

Hmmmmm....car had a replacement rebuilt ecu fitted by previous owner about 3 or 4 years ago after it got flooded....hopefully that's not the problem

Hi Guys,
Car still has exactly the same symptoms....fires up very rough and dies with any throttle input...
Fuel pressure dropped from 30psi to 22psi overnight on test gauge.
Tested all the engine related sensors today as per wsm specs and they are all good.
Tested all HT leads for continuity & resistance all between 2.5 & 4k ohms.
Replaced all plugs (yep....getting that desperate).
Put a new bosch coil on and no difference.
Reluctor to contact air gap .009". Visual inspection of reluctor and wires in distributor is good...nothing cooked, broken etc.

Car has run pretty much perfectly for the circa 30,000kms I've had it and been regularly maintained.

As always, suggestions welcome as I am getting nowhere at present.

Cheers, Charles