Anyone have an original ECM to spare?

[Rangerdoc]

I've had a long history of my 84 GN kicking my A$$. I've had it for a year now and it has never really run.

Click here to see the post with the full history.

It is running very rich.
I've finally taken it to a shop that I can trust. The scope has shown that the signal to the #5 cylinder is breaking down. Either the injector is bad, or there is a problem with the harness or ECM.

It would be really nice if I could try a known good ECM to see what happens. With all teh people who upgrade, there has to a lot of hot air ECMs floating around out there?!

Can anyone send me a known good ECM to test? I'll pay all shipping of course. I can then return it or buy it if it does fix the problem.

Thanks.

Post or email me at jashar@earthlink.net

 

[FJM568]

Are you talking about to the spark plug are are you talking about signal to the fuel inj??? If it's the signal to the spark plug, you could have a problem with the plug wire, spark plug, ign module/coil pack, wiring harness or even the ESC module...As for the fuel injs, you could have a shorted fuel inj wiring harness, or even a dead or dying fuel inj, or possibly a bad inj driver in the ecm, hell, even the harness for that particular inj may not even be plugged in all the way...Could really be any number of things...

Here we go again, throwing parts at a problem before the problem is located for sure...There are troubleshooting charts out there to help with this...They can be found in the factory service manual...I believe they are once again available through Helm Publ. I bought mine several years ago through a company called Lloyd's Literature 1-800-BY-A-BOOK...They will run at least about $120

 

[mycarsucks]

FJM568 I agree with your opinions of the hot-airs problems, however, I don't think this is the case. In fact I think this person has done their job pretty well. Upon closer reading it appears that the problem as been narrowed down to fuel and not spark. It has also been narrowed down to an individual cylinder.

I think in this case that substituding a known good ecm for a mere price of shipping would be a good next step.

Now, if it isnt narrowed down to fuel and he thinks that it could be spark as well I agree that it is the wrong step to take at this stage.

 

[Wildthing]

I have a complete 84 GN engine that I'm interested in parting out. I have located a complete 87 intercooled engine to put in my Monte Carlo SS. I have to agree with FJM586 about doing some basic trouble shooting. The manuals from helms are great; I have one for my 88 MCSS. I have a lot experience with ECM's; I program them for a living. I'm a computer engineer for CAT. The most proable cause for your problem is the wire harness. Over time with abrasion heat and oil exposures the insulation on the wires will degrade and cause shorts to ground. Also the resistance of the copper wire inside will increase with time. Next proable cause is the injector coil, same reasons as the wire. It is just thin copper wire with very thin lacquer insulation. The least proable cause is the ECM. Most of the time a driver will fail completely. It is still possible for the ECM to be the problem. Try resistance checks of the wire and resistance checks to ground. Then due resistance check of the injector, the service manual should tell you about how much resistance you should see. It probly will be between 8 to 12 ohms. If you are still what a ECM let me know.

 

[Rangerdoc]

Got an ECM on its way.

Thanks for the ideas...

We're talking about the fuel signal, not spark.
I agree that it is least likely to be the ECM, BUT...at least this way I can very quickly and cheaply eliminate the possibility. Gut feeling says it's either injectors or harness. Right now, trying a new ECM it is the fastest and cheapest step in the process of elimination.

Thanks to Brent... he's going to send me one for a paltry shipping fee.


I'll post the results in a few weeks when I return from travelling.

 

[Boost231]

hey

hey man its no big deal i try to help people out as much as possible. i just wish i could save $$$$ faster so i can get my car painted and put back togther so i can run 11's. well keep us up to date on the car.

brent

 

[xxninja]

i would check the parts for sale section in the posts
im sure u can find alot of working ecms for around $35-$45 in that section because.......

it seems every1 gets rid of their 84/85 ecm cuz they swap it out for an intercooled ecm so they can run preformance chips and use a SCANTOOL

i would just do a search of 84/85 ecm in the parts post
sure u wont have a problem finding them

brian

 

[Boost231]

hey

i told him if he wants mine is for sale. he is going to see if its the ecm and if so he said he was going to buy it from me

brent