Could a J3 port go bad?

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Could a J3 port go bad?

Unread postby Trogdor » Thu May 07, 2020 12:16 pm

Hello,

I was having problems with some random misfires, or more it felt like power was cutting on and off and it was randomly, but pretty consistent. It would do it while cruising at a steady speed and also while accelerating. No distinct pattern to it, it would do it warm or cold.

When I first bought the car I had a friend from a shop get me an SCT chip with a custom SCT program on it. When I wen to install it, I found the someone that owned the car before me had installed one of the old blue Superchips. I removed it, installed the SCT chip along with the cable and switch.
All seemed well until one day the car just died and would not restart. I pulled over and finally changed the tune switch from 0 to 1 (nitrous tune). Car fired right up! Got home, check all connections and all seemed well unless I would change the tune back to 0. Then I would have random times when the engine would die, or die and immediately come back to life. At that point I just thought that the second hand SCT chip I purchased was somehow bad and removed the chip. Car ran great, no more random engine dying.

Fast forward to a few months ago, I purchase a Quarterhorse as I'm planning on a heads, cam and intake upgrade and want to learn how to tune before I start changing engine components. I install it in my EEC and pretty much I start getting random moments when the car will judder and act like a misfire, but it's more like someone is cutting the ignition momentarily. I don't have any backfires and I don't have any intake popping, just the car missing for a split second. When logging, nothing shows up out of the ordinary. I got a new QH (the first one was a second hand unit and the battery died) and the problem was still there. I was hesitant to remove the QH since my electric fans are controlled by the EEC now, but I did have enough time yesterday to take the car out around the block without the QH and see if the problem was still there. Problem is gone. Car is smooth all the way through the gears. Also now the fans come on as soon as I turn the key.

I did replace the capacitors in the A9P a couple of months ago when the car died and then the fuel pump would constantly run. I thought that maybe that is why I was having the issues, but once replaced the issue was the same.

I did not have the pleasure of cleaning the J3 port, but the person that did left the contacts all silver on the bottom and silver and copper on the top. Could this be the issue?

Thanks!
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Trogdor
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Posts: 31
Joined: Mon Dec 09, 2019 4:20 pm
Location: Anna, TX
Name: Matthew
Vehicle Information: - 1993 Ford Mustang 5.0
- A9P
- A9L2
- Moates Quarterhorse with TunerPro RT
- Innovate LM-2
- Stock 302
- 5 Speed conversion
- Stock Heads
- Stock Intake
- In fender CAI
- 76mm C&L MAF housing
- 70mm BBK TB
- Aeromotive adjustable FPR
- Nitrous Works 125 wet kit
- 24lb injectors (Old Ford Motorsport)
- B Cam
- March underdrive pulleys
- 3G Alternator (Factory pulley)
- Mishimoto aluminum radiator
- Contour fans
- Ceramic coated BBK shorties
- BBK X-pipe
- 2 chamber flows

Re: Could a J3 port go bad?

Unread postby decipha » Thu May 07, 2020 8:07 pm

yea it sounds like you still have some plastic on the j3 port still
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Re: Could a J3 port go bad?

Unread postby Trogdor » Sun May 10, 2020 11:36 am

I did recheck and all the plastic/rubber coating had been scraped off already. I went ahead and replaced the A9P with a T4M0 computer and ran extra wires so I could switch back and forth. I want to thank you again for making this swap so easy!

I also took out my Performance Distributors distributor and put the factory back in. After these two changes the car has never ran smoother since I've owned it! The tach used to have this issue where it would start bouncing around at high RPM and now it's steady all the way through. I'm guessing that the old ECM was slowly going South and I was just getting used to the little quirks the car was getting. Not anymore! Thanks again!
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Trogdor
General Poster
 
Posts: 31
Joined: Mon Dec 09, 2019 4:20 pm
Location: Anna, TX
Name: Matthew
Vehicle Information: - 1993 Ford Mustang 5.0
- A9P
- A9L2
- Moates Quarterhorse with TunerPro RT
- Innovate LM-2
- Stock 302
- 5 Speed conversion
- Stock Heads
- Stock Intake
- In fender CAI
- 76mm C&L MAF housing
- 70mm BBK TB
- Aeromotive adjustable FPR
- Nitrous Works 125 wet kit
- 24lb injectors (Old Ford Motorsport)
- B Cam
- March underdrive pulleys
- 3G Alternator (Factory pulley)
- Mishimoto aluminum radiator
- Contour fans
- Ceramic coated BBK shorties
- BBK X-pipe
- 2 chamber flows


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