ECU connector problems

[pdooley]

86 turbo t.
Car wouldn't start so I checked the connector plug for the ECU. It had slight corrosion so I sprayed the connector plugs and ECU socket with CRC contact cleaner.
Waited a day for everything to dry, snapped it together and she fired right up, actually ran better than before.

So, I figured a little preventative maintenance was in order.
I pulled the connectors back out and coated everything with di-electric grease.
Snapped the plugs back in and no start again. Even after cleaning all the grease back out it still wont start.
In all cases of no-start, the fuel pump didn't prime when key was turned to run. This got me to the ECU connection idea in the first place.

So i figure the connectors are just tired, maybe lost their tension and not making good contact.

What's the best way to fix this? Can the connectors and wire terminals be replaced? Is there a kit available?

 

[RmvBfrFlght]

I think that the grease needs to be fully removed. The terminals have flat sides where they contact the pin. Which makes it easy for grease to prevent contact.

The terminals can be re-tensioned. They are sort of barrel shaped, with four sides. Once removed from the connector can gently(!) squeeze them tighter, then re-insert into the connector.

RemoveBeforeFlight

 

[pdooley]

how to clean? worlds smallest q-tip?
maybe some really small pipe cleaners.
i was thinking of blowing compressed air in the connectors to force the remaining grease out the back of the plug, then hitting it with more contact cleaner.

thx for the tip on re-tensioning. it there a special tool needed to extract the wires?

 

[RmvBfrFlght]

I'm not really sure what to use to remove the di-electric grease. Maybe BrakeKleen will do the trick. Just try a drop of it on the connector housing first to make sure that it doesn't attack the plastic.

If it doesn't, then blast away from the wire side and out the pin side. Use some rags to collect the spray/grease. I think if the majority of the grease is removed contact will be made.

For R&R'ing the pins, have something book-marked. Here it is, although I don't believe an non-sponsor URL is allowed. Try this, go to google and drop this in for a search string:

+dynamic +move +ECM +pins

Should be near the top of the results. They don't sell anything turbo Buick related, so I should be OK posting this.

I wouldn't remove more then a pin at a time. And keep track of which opening it goes back into. The pseudo link also shows how the pins are numbered.

RemoveBeforeFlight

 

[pdooley]

search worked, i got the link.
looks like i got a project now...

thx so much for the help!

 

[GNVenom]

You can clean it all weekend long, but it won't solve the problem.

Once you see corrosion on the terminals of the connector, it's all over...the tin plating has broken down, revealing copper, which corrodes regularly. The terminals self-destruct. Dielectric grease won't help, since the tin is already gone. Contact cleaner won't help either.

The only fix is to replace the terminals and connectors. You can splice in a repair end, or replace the terminals individually, but you will need s specially made crimp tool to do that.

Fix=pigtail install.

 

[pdooley]

questions:

1)where to buy a pigtail? available new or junkyard?

2)if the connector is bad, how do i know that the ECU pins aren't rotton too?

 

[novaderrik]

i had to get a different ecm for my car because of corrosion.
on the orange wire that gets battery power to the ecm, the pin in the ecu side of the plug corroded to the point that it broke off.
at first, the car would start sometimes, then it might run for a while or die at random intervals. after a while, i noticed that the 'check engine' light wasn't coming on when it wouldn't start, so i checked all the fuses, which were all good. then i pulled the plug out of the ecm to check for power with a test light, and it looked good at first. so i plugged it back in. it worked, for a while. when it didn't work, i'd wiggle the connector and it woud start, then die. when i unplugged it again, i noticed the broken off pin stuck in the connector.
so, to sum up this long story, i was forced to upgrade to the better 87 ecm and a turbotweak chip, and the corrosion was caused by the drain in the heater box being clogged and allowein rain water to overflow and drip down on top of the ecm.

 

[bishir]

Gnvenom who replied is owner if Casperselectronics. Contact him! He has the kit and crimper you Need! Don't try doing it without a crimper. I did this job last week. Just do one wire at a time and you should have no problems.

 

[pdooley]

thx for the replies guys and novad don't worry about being long winded, i appreciate the info.