Are all ECUs created equal?

[HALIFAXHOPS]

Was looking for when we were not taking them apart but showing real Mopar ones and junk. Think it was right after that.

 

[Stephen Hotz]

https://www.forabodiesonly.com/mopar/posts/?post_id=1970174354

 

[rumblefish360]

From Cbodies forum.

The blue or gray or black box is stock. The orange box is aftermarket mopar and supposedly has a bit more dwell than the stock. The Chrome is also a street strip box with supposedly even more dwell time for a hotter spark and better combustion. Gold box is race only supposedly and I imagine has even more dwell time.

From what I have read you should avoid the orange box. they tend to have a high rate of failure.

Less dwell time.....

 

[66Satellite47]

I have an old Blue box P3690256 5 pin, correct ballast resistor combination, instructions. This early Blue box runs well past 7000 RPM. Ran it for 1 season before going to the MSD 404BC. The Blue box was my spare on the car for many years I used it a few runs a year to verify it's function. Also have a Mag DC distributor from '77 or so. Have a MSD 404 BC box with very little use. I'll post an ad for the parts I have.

 

[69/70Plymies]

Nacho-RT74,
I did say...."possibly needing a 5 pin ECU". I was speaking along the lines of "plug in and go" type scenario (without modifications, etc.). However, thanks for the modification details.

 

[westie47]

Perhaps? To my understanding, the 4 pin ECU obtains it's power from within itself, thus only needing a 2 spade ballast resistor. This is the later design in electronic ignitions. The 5 pin ECU receives it's power returning from a 4 spade ballast resistor. With that said, check your Evans harness for the two ballast terminals. If EACH terminal has two female connections, the harness is wired for a 4 spade ballast resistor, thus possibly needing a 5 pin ECU.

I’ll check the new harness. Oddly enough, my car has two ballast resistors and points ignition...I was a bit perplexed.

 

[westie47]

Will it matter what coil I use? I have a MSD Blaster 2 for the car.

 

[69/70Plymies]

Will it matter what coil I use? I have a MSD Blaster 2 for the car.

Depends on your intentions for the car. If just a driver and fun once in awhile, I would stay with an OEM/OEM-Spec. coil. Review the info. on post #4 (page 1) and post #8 (page 1) for general direction if you're wanting something more.

 

[66Satellite47]

IIRC the Blaster 2 has a pretty wide range of applications.

 

[westie47]

I’m not doing anything crazy, has aluminum intake, headers..possibly cam, electronic ignition...I got the Blaster 2 and Streetfire plug wires as well.

 

[66Satellite47]

The 256 box is excellent. It easily runs well past 7000 RPM with the right coil. Mopar said it's not intended for driving more than 30 minutes.

 

[Bee1971]

P369256A Blue ECU.. Is it the old race one??

 

[66Satellite47]

Yes

 

[Sixpactogo]

In defense of the orange box that lots of people claim has a high rate of failure, I can say I have never had one fail because of workmanship in over twenty years on two different cars and a pickup truck. IMO, the failures are more than likely caused by a bad case ground. I learned that lesson back in 1989 when my 65 Sport Fury with a fresh resto and a new orange box conversion would shut down after a 10 or 15 minute drive. After cooling down, it would start and run until the transistor got overheated again. My research showed a 20 ohm resistance between the orange box and neg post on the battery. I corrected that resistance to .01 reading and that same orange box is still doing its job after a half dozen shutdowns because of the excess current flow.

 

[toolmanmike]

In defense of the orange box that lots of people claim has a high rate of failure, I can say I have never had one fail because of workmanship in over twenty years on two different cars and a pickup truck. IMO, the failures are more than likely caused by a bad case ground. I learned that lesson back in 1989 when my 65 Sport Fury with a fresh resto and a new orange box conversion would shut down after a 10 or 15 minute drive. After cooling down, it would start and run until the transistor got overheated again. My research showed a 20 ohm resistance between the orange box and neg post on the battery. I corrected that resistance to .01 reading and that same orange box is still doing its job after a half dozen shutdowns because of the excess current flow.

Clean off the paint, install a star washer or a external ground wire. (or all the above)