fbarnhill

Well, I am pretty sure that in diagnosing my rough running issue, I have shorted my ecm. I was just following the manual and testing the leads on the connector to test the temp II sensor. Well, after plugging it back into the computer, I get nothing but rar rar rar...

Anyone have one out there they would let go reasonable???

Is there a test that I can do to ensure this is the issue?

Thanks, guys, any help at all will be appreciated. I have been over the hill and back with this darn car.

Kevin in Atlanta

PM me I have one.

soontobered84

Frank,
You should be asking if someone is willing to plug YOUR computer into their known running car to see if your computer works. There could be something with your car that wants to burn down computers and then you will have 2 non-functional computers.
Just sayin'

PorKen

Check the Temp II readings at the ECU. The wiring may be faulty.
https://rennlist.com/forums/928-foru...2-pinouts.html

Could also be flooded. Remove the fuel pump fuse or relay and crank it with full throttle.

Charge the battery! Battery voltage is important. The computers need well over 10 volts while cranking to work properly.

Mrmerlin

As always a fresh battery will do wonders for a slow turning 928 engine.

I talked with Frank he has reported these issues.
The TPS short harness has the broken off connector into the car side of the harness,
The Crank Position Sensor connector has also cracked off into the car side of the harness,

The temp 2 sensor is new and has been tested and its reading properly,
the Temp 2 connector is also new but has not been tested at the computer connectors yet.

I am not convinced the issue is with the computers,
and had also advised Frank that he needs to put his computers into a running car instead of getting another set.
So the idea for another set has been tabled.

The other report is that the engine has never ran properly since it had a valve job ,
and giving the engine more throttle while on the hiway cruising makes it stumble and bog,

This leads me to believe that one of the cams timing may be off a tooth on the chain .

Checking the timing belt timing, then
doing a compression test should verify this.

We are waiting for parts to be ordered and the timing check and compression test
The compression test should be performed with a fresh battery.

dr bob

Stan --

Dufo cam timing will show up instantly with a vacuum gauge. Maybe quicker/easier than running full compression sequence, although with fresh heads-off service knowing compression is good is useful. vacuum gauge is a good first-filter.

Mrmerlin

Dr Bob ok thanks for the idea, will add it to the list ,
Anyway since the engine doesnt run,
testing via vacuum is not an option for now.
Now the basics have to be fixed new CPS and TPS short harness.

SeanR

I think Dr. Bob means doing a compression test. This will tell you if your cams are off. Don't ask me how I know.

fbarnhill

Thank you all for your excellent suggestions. Stan has agreed to QB this duagnostic and I can't tell you how much better I feel about it. I can't wait to proceed. I will try to keep this documented as best I can And share it. I guarantee someone else will need it in the future.

fbarnhill

Diagnosis. I have autocorrect😁

davek9

I'll throw this in for the WOT stumble issue, I've seen a single bad spark plug connection do the EXACT same thing.

Mrmerlin

Dave great suggestion, new ignition wires are also included in the diagnosis.