This one has me stumped

[LazerDude]

I have a '90 PLymouth Laser 2.0 N/T manual fwd. This car has 323K miles on it and recently I started hearing a clicking coming from the center console. At the same time of the clicking the dash lights would flash and the car would stumble. My first thought was the ECM so I pulled it and had it sent off to be diagnosed and repaired if needed. As it turned out the ECM was a factory up-graded replacement and checked out perfect. Since the MPI relay is right there near the ECM I felt that it could be the culprit. I reinstalled the ECM and replaced the MPI relay with a known good one. After I put it back in I made sure all of my connectors were good and seated and that all other electical connections were tight and the terminals clean and tight I drove it around the complex here for a few minutes and it did it again. I didn't have the covers on and it is clicking back through the MPI relay. The book isn't showing anything and when I probbed the ECM I am getting a "normal status" code from the ECM. I have worked on these things for almost 18 years and this has me stumped, what am I overlooking?
Mike

 

[redyute1]

find an other ecu to try,pretty much syntoms of a bad ecu

 

[DSM1G90]

I call it a contact issue causing that relay that controls the ECU to click on you like that. Made sure that all contacts are connected real tight, or any loose wires within harnesses themselves? How about any wire connections from the back of the key assembly in the steering column - sometimes those large connectors within those harnesses do love to work themselves loose.

 

[LazerDude]

As I said, I sent this one to Motoguys garage that specializes in the 1G ECMs. They put it on a test bed system and then on a test car and ran it and it did not produce any faults. I do not have access to another '90 model ECM but I have 2 good ECMs for a '92 model but it is my understanding that there are a couple of wires on the harness that have been pinned out differently between the 2.

This problem also started shortly after I had to replace the heater core which is making me wonder if I don't have a pinched wire.
Mike

I call it a contact issue causing that relay that controls the ECU to click on you like that. Made sure that all contacts are connected real tight, or any loose wires within harnesses themselves? How about any wire connections from the back of the key assembly in the steering column - sometimes those large connectors within those harnesses do love to work themselves loose.

I will check those connections on the column in the morning. Having to move the entire dash assembly out of the way may have loosened one of them up. I am just tired of driving my old '69 Ford F150, it's about like driving an old grain truck. I miss driving my baby!
Mike


I checked up on the connections and all of them were tight. So far I have put about 15 miles on her and she hasn't done it again and is running strong. I want to get some more run time on her before I decide to get on the highway.
Mike

I drove her to Spokane and back, that was close to 70 miles and no kicks, all is good.
Mike