[urq] Re: No Start[spark or fuelpump] condition with no codes generated

[Ben Swann]

Steve,

Read through what I have documented at: http://www.homestead.com/ben_swann/MCWiring.html

As you will see, I have checked this throughly.  This is no less than the third MC engine I have completely rebuilt and installed.  The main difference this time is that the electronics need to integrate with those in the GT Coupe.  

I did get a code generated  earlier when I had those sensors swapped, so it is picking up codes.  Now it appears the signal that triggers the coil and also the Fuel Pump relay is not getting there.  So the ECU thinks it is putting a spark out the primary wire.  I just don't know what that wire is.

The question as I can narrow it down is:  what pin on the ECU harness is supplying the primary to the coil?

The Bentley wiring diagrams do not show this, but instead show the coil wire coming from the Idle Stabilizer Valve Control Unit.

Thanks for looking.  I know I have replied on this similar question before, except usually there is a code that can be looked at.  Now I am having the difficulty and have eliminated the codes for things I found that were bad or miswired.    At this point, I have become partly blinded due to my frustration of this whole project taking way too long.  I ask for help from others when I think some outside eyes can help find the obvious thing I am missing.  I can assure that this is not an easy one and anyone who wants to take a stab at it will likely need to at least look at my wiring writeup and probably the wiring diagram for the '87 5000 turbo engine/car.

Thanks,

Ben

[... I have not researched this myself, but it is my understanding that
on the MAC-11 the ECU does not activate the fuel pump relay until it
gets satisfactorily timed flywheel (and perhaps distributor) signals.
If I were in this situation I would put my focus on this angle ... are
you sure the distributor timing is correct? 

YES!

 Do you have the referencepin in the flywheel?  Is it in the correct position for the MC? 

YES!

 Given that this is a transplant, one other thing I would want to verify is that there isn't some sort of a grounding situation which is causing excessive noise on the signals. 

No grounding problems or sheilding problems.  I am betting the signal is being generated in the ECU, but never gets to the coil - I am missing a connection somewhere.

Have you taken an oscilloscope and verified that the engine reference, engine speed and Hall sender signals
look good at the ECU connector while the engine is being cranked?  

I don't have an O-scope on hand, nor do I think it is necessary at this point.

As to the engine codes ... are you sure the feedback mechanism is working at all?  Have you tried forcing a failure and seeing whether or not the associated code is getting generated?

YES!

Good luck!
Steve B
San Jose, CA (USA)]