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So my jeep lost cylinder 1 and 2 a few weeks ago. I’ve been kinda down about it and a little irritated but I’m over it.

I take extremely good care of my vehicles. I’ve had the jeep 15 years. 96 XJ, long arm y link, over the axle trackbar, over the knuckle steering, WJ swap, big brakes, offset knuckles, full custom job up front.

Anyways, she had never let me down until this time. I went through the ignition system this weekend. Fuel system. It’s getting spark, air and fuel. But only 2 cyl down. It has great compression in all 6 holes.

I scratched my head. Took me a few hours to remember the spare computer I have. I pulled it out, went to install it and found this:



I’m in the California desert. WTF! What would you do?

I’m thinking of disconnecting the battery and soaking the harness connectors in vinegar. Then wire brushing the computer.

If that doesn’t fix it - I have a feeling the corrosion made its way into the computer and fried one or two injector drivers.

WWYD?

Good question, I'm interested in the replies and suggestions. With car battery terminals, you'd basically scrape away the corrosion. Could you get a strip of 400-grit sandpaper in there and go sideways across the tops & bottoms of the rows of pins, to at least physically remove the corrosion from parts of the pins? I do a similar thing with the ignitor in my furnace every few years when the striker doesn't ignite it anymore...a little scrub with some 400-grit sandpaper on the ignitor pin and it's good to go for another year or two.

Whatever you can get in there to scrape and clean will be helpful. Possibly vinegar applied sparingly. Soak down with contact cleaner and apply some contact antioxidaton grease before assembly.

You may try a simple firm bristle tooth brush and some alcohol first. If the pins are bigger then they look a nylon bristle brush. It would be good for getting inbetween and around the pins.

I'd use contact cleaner and an acid brush. Then blow it out with spray can air. If that doesn't get it all, a fiberglass pen might work.

I'd also spray and blow out the connector. After confirming that everything works, I'd flood the connector with dielectric grease.

Coelacanth wrote: ↑Tue Feb 27, 2024 12:31 pm Good question, I'm interested in the replies and suggestions. With car battery terminals, you'd basically scrape away the corrosion. Could you get a strip of 400-grit sandpaper in there and go sideways across the tops & bottoms of the rows of pins, to at least physically remove the corrosion from parts of the pins? I do a similar thing with the ignitor in my furnace every few years when the striker doesn't ignite it anymore...a little scrub with some 400-grit sandpaper on the ignitor pin and it's good to go for another year or two.

For the ECU “pin side” I’ll very lightly wire brush and baking soda and water then DI water and air blast.

For the harness side I can actually submerge it. Maybe just baking soda and water bath? I want to etch the female brass connectors buried in the harness connector if possible. That’s why I was thinking of using vinegar.



I absolutely 110% put a light smear of dielectric grease on these connectors 13 years ago. You can see it turned hard and cracked off in the first pic.

That connector is yikes..something like I’d normally see here in Illinois.. surprised your only having one problem! I usually use Deoxit and a narrow wire brush to clean the computer pins and round terminal files to clean the harness connector. With a lot of corrosion like that you might have poor connection/pin fit after cleaning…might want to start checking with local junk yards to find a nice set of connectors to replace yours.

BattleTrak wrote: ↑Tue Feb 27, 2024 3:30 pm That connector is yikes..something like I’d normally see here in Illinois.. surprised your only having one problem! I usually use Deoxit and a narrow wire brush to clean the computer pins and round terminal files to clean the harness connector. With a lot of corrosion like that you might have poor connection/pin fit after cleaning…might want to start checking with local junk yards to find a nice set of connectors to replace yours.

This is painful to accept

A few years ago the speaker in the back of my truck would cut in/out. Popped the door open and the connector wasn't unlike yours, heavily corroded and a bit loose. I doused it in soldering paste and hit it with an soldering iron, that made very quick work of the corrosion! I wiped things down really good and reassembled, it's worked fine ever since, probably about 3 years now. I don't think I'd want to try this with a connector like yours for fear of melting plastic or leaving residue that would allow or promote further corrosion.

For your ECU connector, I'd go the route others have suggested and use a brush and electrical contact cleaner, something that doesn't need to be rinsed away because water/moisture is the root cause of the problem to begin with. Definitely follow up the cleaning with dielectric grease. Check the seal on the connector and the connector housing, if either are damaged, then replacement of the connector may be necessary.

FWIW, I'd be willing to bet that the ECU is fine, it's the connector itself that is the cause of the problem.

Those connectors look to be mostly "weatherproof". I would maybe "flood" with MAFS or QD cleaner (CRC is the brand I'm familiar with). Like, upright and puddled then like folks are recommending, soft, long bristled brush. Quick, dump, fill, brush, dump, etc.. That female connector though....maybe use the cleaned male with some flooded connect/disconnect wet friction dislodging. Flood float those flakes outta there..let the unit sit and all the cleaner evaporate.. then the dielectric grease final reconnect.

There is product out there that will remove corrosion from battery terminals/cables. It would clean those male pins real nice like. But that female side...I don't know...you would have to make that call...but alot of QD electronics cleaner is called for regardless.