ecu box problem

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Darren

Darren

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Hey guys I have had a problem with my 68 Cuda getting spark. I recently changed from points to a proform electronic ing with a blue ecu box. It seams that when I push really hard on the ecu connector and wiggle it the car will start and stay running. I Grounded the box with its own strap. And you can't put to much torque on the little screw or it will spin the steal grommet on the inside. I am starting to think somthing is loose on the inside of the ecu box. Anyone experience this? Thanks
 
Junk yard connector ? The round female terminals inside the harness connector might be stretched in diameter and/or corroded. New are available. And like their other round female terminals, they were ovaled. So on a round post, contact was at 2 straight narrow lines instead of all the way around.
The screw in its center ... about worthless. Over tightening will draw the nut right off the plastic post its crimped to in ecu. Maybe the connectors never did fit really well. Thus a screw to keep it from falling off where the box is mounted vertically.
 
It is a complete new kit. I did crimp the female connectors in the connection just a little. But did not seam to help. I was thinking maybe some diode lube maybe.
 
GM HEI 4 pin module,

Go to www.designed2drive.com for a nice neat mounting bracket for your distributor.

Use either a genuine GM 4 pin, or a Napa echlin.

Remove all the wiring you just installed but keep distributor.

If you mount the module on the distributor you will need a very minimum of wire to connect it to the ign coil. And can use the cars existing harness. The only mod to it will need is to remove the ballast resistor in the ignition circuit, and connect the wires together to get 12V to the ignition module.

Go HEI on that proform mopar distributor. Way, way hotter spark than what you have with the mopar styled brain box which requires a 6V resistor and hobbles the system.
 
Check out my hei install pix on my distributor on another thread in this electronic ignition forum. Its titled something like distributors bang for the buck. On page 2 near the bottom i have pics of this install. Its clean, compact, and eliminates a bunch o wires.
 
moparmat2000 said:
GM HEI 4 pin module,

Go to www.designed2drive.com for a nice neat mounting bracket for your distributor.

Use either a genuine GM 4 pin, or a Napa echlin.

Remove all the wiring you just installed but keep distributor.

If you mount the module on the distributor you will need a very minimum of wire to connect it to the ign coil. And can use the cars existing harness. The only mod to it will need is to remove the ballast resistor in the ignition circuit, and connect the wires together to get 12V to the ignition module.

Go HEI on that proform mopar distributor. Way, way hotter spark than what you have with the mopar styled brain box which requires a 6V resistor and hobbles the system.
Click to expand...

Very interesting I will be looking into that as a future project.. but for now I will to get this system working. Thanks
 
That grease is an insulator, it for boots, not contacts. It seals from moisture and helps keep the boot from sticking. There are products with conductive materials for use on connections, but they are not for plug boots.

I tried to help, but my search for proform blue could not find your box. Often one uses model number or link to where they found it.
 
Dielectric grease does not aid in electrical connection, in fact it does not conduct. It is a corrosion inhibitor only.
 
Just tried to start the car... nothing. Then I push on the box connector and she fired up . But yet the connector is tight. Going to have to play with it more when the kids have there nap lol.
 
You could very well have a break or a poor crimp where the wire(s) connect to the terminals in the connector boot. That is one reason when guys have problems with these, I always suggest working the connectors in/ out

For future "tuck it away" the distributor connector is far more problematic, as there is almost zero current through it. The slightest bit of "loose" or corrosion can stop the trigger signal.
 
Update.. I had an old black ecu in my stock pile. Installed it and the car fired rate up. So I guess my test is to leave it over night and see if it starts in morning. I have no idea what this black ecu box is from. Can I do damage to anything by running it? I noticed that my original blue box has 4 pins and this other black box has 5. The 5th is not wired up. As per installation instructions. Thanks
 
You cannot tell a 5 pin box from a 4 pin by looking. Many of the aftermarket replacement boxes are "4 pin" but actually have 5 physical pins. Only way on unknown box is to check resistance off the 5th pin to the others

Most/ all NEW replacement boxes will be 4 pin

And "no" you cannot hurt anything with this box

I would run the car and wiggle the connector. Hold the connector in and gently tug on the wires which come out of the ECU connector one at a time
 
Took her for a ride with the black box and it ran like it was on 6 cylinders. So I went back home and put the blue box back on and it started and ran really good. But we will see if it will start in the morning..
 
Darren said:
Very interesting I will be looking into that as a future project.. but for now I will to get this system working. Thanks
Click to expand...

Hey no problem. I wish i could help. Other than grounding the box better, making sure the pins make contact, checking ballast for continuity, and checking the pickup coil for continuity and a dead short to ground i dunno what else to check.

Reinstalling the blue box and it running again, i dunno. Maybe it got a bit of a better ground this go around. I know when i helped my dad restore his 79 lil red express we sanded the paint off in the 2 spots on the firewall where the module went, and sanded the paint off the back side of both mounting tabs and had no issues.
 
Lol... it was hard to sand the fresh paint off the firewall to mount the ECU and also I mounted a separate ground strap from ECU to firewall. Might go price a new MP orange box tomorrow.
 
New Mopar-compatible ECU boxes have been problematic and questionable quality. One guy here opened one up and found the traditional TO3 transistor sticking thru the case was a phony. Not terrible by itself, since much smaller modern transistors can manage the current today. But, the real transistor was just pressed against the top for cooling, which was not reliable long-term. I think Pro-form sells only low-cost made in China parts. Some are OK, some questionable.
 
I agree. Its a shot in the dark with the china made electronics. I purchased a set of speedmaster aluminum heads. My machinest said they were not bad at all for an eddy copy once we change the guides out for better ones. You are def better off with a factory spark box. I have seen some pix on fabo of the chrysler spark boxes gutted out and HEI 4 pin modules inserted inside, and wired up to the spark box pins. Interesting solution. Also cracked open a jaguar XJS V12 spark box a neighbor was having trouble with his car. New box from Jag was $250. Imagine my surprise when after digging the potting compound out i found a standard GM HEI module inside. We went to the store and bought a replacement module and fitted it back into the jaguar spark box for about $25 LOL.
 
Can you take a picture of how you grounded the ECU box? I am having the same issues. Just wondering where you grounded it exactly. Thanks in advance.
 
Me? I'll just stick with my cheap old 4 pin GM ECU. "One of these days" I might hide it in a Mopar Box, LOL
 
Spunk said:
Can you take a picture of how you grounded the ECU box? I am having the same issues. Just wondering where you grounded it exactly. Thanks in advance.
Click to expand...

You can see the ground wire goes from the bottom mounting screw on box to body ground on far left of pic.
Got a new orange MP box on order. Hope it's the problem...
 

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