How to test a 1990 GST Power Transistor Unit and Coil Pack harness?

[DSM_One]

Hey guys, I'm trying to fix a random misfire on my car and suspecting either the coil pack or the power transistor unit. Thing is, I wanted to test them both but my Chilton Manual is not enough. The ignition coil harness of a 1990 GST has 4 pins while the manual states 3 pins. The power transistor unit of a 1990 GST has 5 pins while it says different on the manual. I have research on this quite a bit because I'm quite baffled by this and a 1990 indeed has 4 pins on the coil harness and 5 pins for the power transistor arranged as 1 2 X 3 4 5 or is it the other way around?

Does anyone know how to test these two and give me instructions or can point me to a site where there are instructions or is the Hayes manual any better than the Chilton's?

 

[girlieracr4g63]

4 and 2 checks #1 and 4 cylinder

4 and 1 checks #2 and 3 cylinder

Hope that helps. Also I suggest buying a Haynes. IMO its better.

123-56 thats for the 90 transistor. This test requires a 1.5 volt sorce.

 

[DSM_One]

Thanks. I'll try that as soon as I can.

 

[DSM_One]

Ok, I tested the ones I bought and both tested fine. I wanted to try them out and swap them with the ones on my car but I'm having a hard time removing the power transistor. How do you guys replaced this thing? Do you actually need to raise the engine? Sorry about the question but I'm no grease monkey. Just trying to be one .

 

[darkness_fallz]

Sorry about the question but I'm no grease monkey. Just trying to be one .

DSM's

Turning regular people into mechanics since 1989.

haha

I didn't have to lift my engine but it was a PITA to get it out.... take your time with it

 

[Diplomat]

"Also I suggest buying a Haynes. IMO its better. - girlieracr4g63"

They're ok to have with you when you're outside working on your car. Though they're also known to have errors in them as well. Personally I'd save my money and get the DSM Backup Manual on CD here.

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It's the factory/dealer service manual which should've come free with your car. After all, we all bought our DSM's to learn how to work on cars, right? You could also visit eBay and search for "DSM Tech Manual" or something along those lines. You'll eventually find someone selling the manual on CD. Sometimes it's a little cheaper this way. Just make sure you're getting the one made by Vineet Singh. His CD includes the Mitsubishi CAPS system. Very cool. This application is filled with illustrations of every part on your DSM. It's used by your local Mitsubishi parts counter person to look up that part you're trying to describe to them since you didn't bring it with you like you should have.

 

[Diplomat]

"I'm having a hard time removing the power transistor." - DSM One

You can remove it with a 3/8" drive ratchet, 3" extension and 10mm socket. I believe there are three bolts. You can't really see all of them. You may want to invest in one of those small mirrors on a telescoping handle. Mine has come in handy on several ocassions. It will take a little patience, don't get frustrated. Trying to remove a bolt that you can't see is a little tough. Don't be afraid to get dirty. Use your fingers and feel around. It may take a couple tries to get the socket on it. When you're ready to put the new transistor on, it's a little easier to start with the bolt that you can see first, then the other two.

By the way, if you have trouble getting any bolts loose, use a ratchet with a longer handle. I used a 1/2" drive with 3/8" adapter.

Take your time, plan and you'll get most repairs done on the first attempt with fewer headaches. If you expect a repair is going to take you an hour, plan for two hours. Always have another vehicle at your disposal in case you need to run to the dealership or an auto parts store. Most important, work safely. Wear eye protection to shield you from anything you might drop or splash in your eye. Very few blind people drive DSM's. Make sure the car is securely supported. Of course we don't discriminate here, but there aren't many flat DSM tuners either.

 

[Diplomat]

"The ignition coil harness of a 1990 GST has 4 pins while the manual states 3 pins. The power transistor unit of a 1990 GST has 5 pins while it says different on the manual." - DSM One

Remember there are slight differences between the:

1G(A) = '90-'91.5

and the

1G(B) = '91.5 - '94

Those differences are more than cosmetic and one of them happens to be that coil pack. There where even some minor changes between each model year as well. This is one of the reasons the DSM Backup CD is a wise investment.

 

[DSM_One]

Thanks a lot guys. I'll invest on a Manual CD and try again on that power transistor