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Old 01-12-2009, 11:50 AM   #1
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Default CEL code 1, loose connection at ECU

I've been chasing gremlins since my engine rebuild and have most of them sorted out. The last major one to deal with is a loose connection at the ECU that causes my car to stall and be unable to run.

Basically, I'll hit a bump and my car will immediatly start running rough. The CEL will turn on, and the engine is unable to be revved past 2500 rpm. If the car dies, it might or might not restart, but it will definitely run rough and have the revving issue.

I checked the code and blinks code 1, which I believe is the igniter. It looks like I've isolated the problem to be a loose connection at connector 1 on the ECU harness. If I giggle the wires there, or manipulate the connector in any way, i can either get the car to run normally or recreate the problem. The connector appears to fit tightly and the wires appear to be solid and well connected.

It doesn't appear to be any of my EMB wiring which is spliced directly into the stock wires at the ECU.

I guess my question is, how can I fix the problem if it is the connector? Would a Boomslang fix the loose connection?

Thanks!
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Old 01-12-2009, 11:53 AM   #2
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Quote:
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EMB wiring which is spliced directly into the stock wires at the ECU.
Seriously, that's your problem. I bet this is where the problem is. You even say "wiggling" the plug/wires here will cause the problem. Seems like you know where the problem is. Fix it. FWIW, I'd solder and heat shrink all the connections so you don't have to worry about wires pulling loose. Some will argue that soldering can break in a vibration prone environment. That said, I got tired of chasing butt connectors that fail, so when I rewired my engine, I soldered everything. So far, it works perfect.
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Old 01-12-2009, 12:35 PM   #3
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Hey Pat,

I understand that loose EMB wires can cause the issue, but I just finshed reconnecting the splices. If I giggle the EMB wires, I don't have an issue, at least none that I could isolate by giggling. Most of those wires are spliced in at connector 2 anyway. It certainly won't be a problem to go back and solder those though.

The problem seems to be directly related to connector 1 though. I don't know what's connected at 1 and I don't know if it's loose pins/wires, or a bad harness, but I'm reasonably certain it's one of those wires or the harness connection.
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Old 01-12-2009, 12:47 PM   #4
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The words you are looking to use are "Wiggle" or "Jiggle" the word "giggle" is this
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Old 01-12-2009, 08:07 PM   #5
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Heh, I do believe this is the first time I've ever used "Jiggle", "Giggle" or any variant of either word, in written form. Duly noted.

Anyway, I just played around with it some more and I'm pretty sure it's localized to the physical connection between the harness and the ECU. 1G and 1H are connected at the ECU and the EMB pretty tightly. JJJJiggling 1H and 1G themselves neither recreates the problem nor fixes the problem if the car is running poorly.

In the past, I've disconnected the ECU to work on the EMB wiring and this issue will pop up periodically. I've pushed the connector in as tightly as it will go, and for now, the connection seems solid.

I guess my main question is, will a Boomslang give me a more solid pin connection between the ECU and harness than my crappy OEM connection?
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Old 01-12-2009, 08:21 PM   #6
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Inspect the factory plug for defects. They are very high quality. If yours is fubared, it's cause someone did something to it.
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Old 01-12-2009, 08:35 PM   #7
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My car has 360K hard, original owner, miles on it. Lot's of high quality Original Equipment parts have either already failed, for various reasons not excluding user error, or are in the process or failing now. I've plugged and unplugged the ECU enough times to feel like I could have fubared something. I've already broken one wire off at the connector. I inspect the pins on the ECU each time I remove it and they look good as far as I can tell. I wouldn't know what to look for on the connector.

Assuming a user induced wiggle room problem with the connector, I guess I'm just looking for a reasonable fix that doesn't invlove replacing the whole main harness.
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Old 01-13-2009, 08:50 AM   #8
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I'm afraid you will need to delve more into the harness/ECU. A boomslang may or may not fix the problem based on where it is. The connectors can be slid out of the plug, inspected for connection to the wire(soldered lightly if the connection is suspect), pinched a little to assure connection to the ECU pin, and re-inserted into the connector.

The ECU can be removed, opened, and checked to see if there is a break in the circuit to the board.

I have had the connections from one end of a boomslang to the other pull off. The workmanship is not nearly that of OEM.
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Old 01-13-2009, 09:38 AM   #9
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Thanks Bruce,

Any suggestions for a tool/source to remove the pins from the oem harness?
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Old 01-13-2009, 11:01 AM   #10
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Quote:
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Thanks Bruce,

Any suggestions for a tool/source to remove the pins from the oem harness?
The ECU connectors seem to be the same as the EMB connectors.
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