Jacob AbuKhader

I have 12.71 volts confirmed at the relay block at terminal 30

peanut

is that both with the ignition switch off and the switch on ?>??

Jacob AbuKhader

Yup that’s both ignition on and off.

peanut

thats really weird .....

If there is 12v+ on terminal 86 and the car runs.......... but won't run with the 12v+ on terminal 30 ???wtf its the same 12v+ from both terminals

is there any chance you could get a clear image of the DME relay base and surrounding fuse/relay box perhaps with a torch or lamp maybe

Jacob AbuKhader

Welcome to the struggle I have been dealing with in trying to diagnose this car hahahahahahahahahahahahahahaha.

Everything works the way it’s supposed to, except it doesn’t work anyway the way it’s supposed to.

peanut

crazy !... its got me beat for the moment but its late and I'm tired maybe I'll figure out something tomorrow . if you can manage a piccy it would be very helpful as I have only owned later cars so i'm unfamiliar with the early fuse/relay boxes

Dan Martinic

I'm taking bets. Odds:

Vacuum Leak - 1000 to 1
DME - 50 to 1
Ignition Switch - 2 to 1

The wire that PO ran for the dash mini-fan he had installed to replace the broken AC: Par

Jacob AbuKhader

I did my best to squeeze in there.

peanut

well the engine runs faultlessly according to Jacob so I'd say the issue has to be a wiring configuration or connection issue which could be caused by the ECU especially as they have both been altered or modified .

Jacob AbuKhader

Lollllll. Well the new relay gets in tomorrow. That should give us a big clue.

Dan Martinic

If jumping 30 & both 87s doesn't start the car, I can't see what the relay will do different. What's interesting is I understand you have tach bounce connecting 86 but not connecting 30. Why would the reference sensor signal(s) disappear when there's a constant draw through 30 but not disappear when switched through 86?

peanut

exactly !....... nothing makes sense about this ............except we haven't got an original unmolested ECU so we have no way of eliminating that at this point

Jacob AbuKhader

Yeah exactly. It’s the latest version of weird hints the car gives me. Before it was the fuel pump fuse. Then it was the coolant temp sensor. Now it’s terminal 86 giving me a start signal but 30 doesn’t.

peanut

its not a signal its just a plain old 12v+ supply .They are identical The only difference between them is that T30 is live all the time and T86 is only live when the ignition is switched on

Dan Martinic

Maybe connect with 30 and check reference signal(s) at the harness with an LED, harness both unplugged from DME and plugged in (from behind, harness cover removed)