RED928

Thanks... I have one on order

Regards,
Steve

worf928

I hope that cures your problem, or at least makes it easier to find your next problem.

That old front-main harness had definitely seen far better days and was - from the pictures - a prime candidate for intermittent issues.

RED928

OK... the saga continues.

Replaced the CPS and there is no change. Car will crank but not start, even with the fuel pump hot wired. Spark? What should I check next?

RED928

I've been updating the interior with new seats/carpeting but other efforts (boat, house, family) keep getting in the way. Still trying to isolate the no start/engine quitting issue. Sometimes starts, sometimes doesn't, will often die if driven.

As mentioned in previous posts I've

refreshed the fuse panel (new fuses/relays)
checked all grounds
replaced computers
replaced engine wiring harness
replaced CPS

I'm pulling the fuse panel/computers today and looking for anything obviously wrong with the wiring like critter nibbles, bare wire, etc. Once back together I plan to again work through fuses, relays, computers (I have a few), and jumping the fuel pump.

Any other recommendations?

Thanks
Steve

worf928

Are you without fuel? Or spark? *this* is the question that must be answered first. Check for spark first.

Mrmerlin

Steve it would be a great idea to post pictures of the engine as this will give details that might not be obvious.

BUT based on the condition of the engine harness you replaced its time for a full on intake refresh,

When the engine is behaving as yours is now this would seem to be the way to go, BUT a few pictures will tell the rest of the story.

RED928

Hi Stan

Here are a couple of pics of the engine...

Mrmerlin

Hi Steve thanks for the link . from the pictures it is time for an intake refresh to happen
What was the condition of the crank position sensor that you replaced?
what do the knock sensor connectors look like?
same goes for the Hall sensor.
Have you ever cleaned the grounds at the back of the V?

This scenario is indicative of an old car needing a major refresh of the intake systems.
you have to understand that replacing one part in the hopes of restoring original performance is a hit and miss operation,
and will result in a a lot of tail chasing.
A full refresh is the way to go.

RED928

Thanks Stan

Would the intake issue cause the start/no start and engine stoppage?

The CPS looked OK.
At the moment the hall sensor is disconnected due to the connector disintegrating. I have a new connector but haven't installed it yet. It was my understanding that would not impact the start/no start/stoppage issue.
I'll check the knock sensor connector.
I'll also check the grounds at the back of the V... are those the ones on the passenger and driver sides at the top of the bell housing?

Regards,
Steve

worf928

RED928

Stan... the knock sensor appears to be a replacement and looks OK.

The grounds at the back of the engine are clean.

Dave... after checking the grounds and sensor I attempted to start with no success. Based on your recommendation to check fuel/spark I hit the MAF with a little starting fluid and she cranked right up. So at the moment there's both spark and fuel. That said, I'm confident the engine will die or fail to start again. At that point I will again try to isolate the fault, which really seems to be an electrical short.

Both... soon as I have fixed the electrical gremlin the refresh is at the top of my 928 task list

Thanks!

worf928

Are they tight?

I interpret the above as: "The engine will run (for a few seconds) if started with starting fluid"

So, that would indicate to me that you have no fuel being injected. And thus, that is the place the start.

Furthermore, this is what I think you've done so far (as far as fueling problems are concerned), let me know if any are incorrect:

- replaced the EZK, LH and FP relays.
- replaced the LH ECU with a known-good ECU.

Have you checked voltage drop from the battery to the panel when cranking?

Next, do you have the Moorehouse CDs?

On those CDs is a factory EZK/LH troubleshooting procedure.

RED928

Hi Dave

When it started with the starting fluid it continued to run just fine. This is very symtomatic of the issue. Sometimes starts sometimes doesn't.

Might have simply been coincidence that it fired and ran with the starting fluid.

The grounds were removed, cleaned, and tightened. I have the CD. I have not yet checked voltage drop.

You are correct with your assumptions.

Thanks,
Steve

Mrmerlin

My diagnosis for your poor running condition is to perform a intake refresh first then continue with the trouble shooting

an intake refresh will solve some of these running issues and at this point you should stop trouble shooting and proceed with ordering all of the parts necessary to do an intake refresh.
Who knows how much air is leaking past the throttle shafts or how old the O2 sensor is or if the MAF needs a rebuild or the dampers or FPR are good or the ignition wires are good
I dont have anything else to suggest to do until this intake refresh is completed.

If you dont follow these instructions then your car may never run properly again.
Its not time to put a bandaid on the car,
its time for major service its expensive and its time for it to happen.

worf928