Bad Power Transistor?

[Maddenmax111]

I have a 95 GST with a 6 bolt swap. I was driving the other day and got on the throttle a bit. When i let off it bogged hard and died. I fired it up again and it ran like crap. It was only getting spark on 2 cylinders. I called the mitsu dealer to ask for some technical help because the plugs and wires were brand new and i wasnt sure where to look in the ignition system. I ended up bringing it to a shop and they said it was a bad coilpack. I changed the coilpack and still same result. I was then told power transistor. I wiggled it around a bit and the spark came back on the two cylinders it was missing but soon stopped again. I guess my question is would a bad power transistor make my car only run on 2 cylinders? Thanks for the help!

 

[1983gsp]

Yes, a bad power transistor will drop 2 cylinders and cause the tach to read 1/2 speed ie:2000rpm is actually 4000rpm

 

[EGLTAWLN]

check the ground wires attached to the engine and make sure they are shinny copper clean.
i've had coil issues related to bad grounding of the engine.
the sensors would not function proper because of the bad ground.
kept getting a CEL 44. cleaned the ground wires and no more bog.

 

[ed1380]

Yes that's possible. A transistor is only $20-25 shipped. Cheap enough to always have a spare on hand

 

[Maddenmax111]

Yeah i just went ahead and bought one last night. 30 shipped to me by monday. I hope this fixes my problem! Thanks guys!

 

[bryanwheat]

You can always just test yours to see if it is bad or not. A 5 dollar multimeter can save you a lot of money.

 

[Rich_Howell]

Most of my Power Transistor failures have tested fine on the bench, but once you introduce engine bay heat over the course of a cruise...there go a couple cylinders. Stop and let it cool and you're good for another 10 minutes.

I hate that damn PowerTR with a passion.

 

[allezgrand]

Yeah i just went ahead and bought one last night. 30 shipped to me by monday. I hope this fixes my problem! Thanks guys!

Can you tell me where you got this? I'm looking for one as well.

Thanks!

EDIT: Nevermind. Used.... got it.

 

[xrdgx]

Yeah i just went ahead and bought one last night. 30 shipped to me by monday. I hope this fixes my problem! Thanks guys!

Where did you get for $30 everywhere I check they are $150-$170

 

[ed1380]

Ebay/classifieds/junk yard

 

[Maddenmax111]

Fixed the problem! it was the transistor. Its amazing how that little part can make your car run like crap!

 

[FlashBack-Cro]

I had the same propblem a week ago. Car was running on 2 cylinders, no spark. And check engine was on. It was a power transistor. I replace it, and it runs again normal.

 

[KemeroDSM]

Same to me, I got P0300 Check engine code, Random/Cylinder Misfire and was the spark plug wires and power transistor, looking to fix that in a shop and they want to charge me $120 for the transistor and two hours labor $160. I did for $40 by myself.

Hopefully we can help about that freaking code

 

[99boostedgst]

would one going bad cause the car to jerk around on cruise and cause a jumpy rev under boost?

 

[Bojangles465]

excuse me for my stupid question, but is it the heat that actualy makes the transistor go bad? if so, does that mean if i put a heat sink on the metal side of it, that would help it? i have like a 200$ heat sink laying around from a server i was building a while ago, and i have no use for it, so maybe that would help? it has two fans and its the perfect size.

 

[ed1380]

I doubt it'll help. I've never had one die on my, and they're only $25

 

[Bojangles465]

oh alright, im having some issues with 2&3, which im hoping is the power transistor

 

[Dayonaise]

oh alright, im having some issues with 2&3, which im hoping is the power transistor

If not the transistor than check the voltage on pin number 55 on the harness sure of the ecu that's what mine was.
Vfaq has the pintout pics

 

[nicolasgeorge]

It's not a little part, it might seem little but it does big things, including diving current to your engine for ignition. Since you're getting it cheap, I'd say buy some more, you'll need them in future too..

cheap pcb assembly

 

[scraze]

i have the same problem on my talon i ordered a ptu from ebay ill post agian to let you guys know if it fixes it i already replaced the coil and the cam position sensor and did a tune up a month ago

 

[Henny101]

Yea i had the same thing happen to me. Replaced the power transistor and got my other 2 cylinders to spark again

 

[bq509]

I recently had the same issue. Cylinders 1&4 had no spark. Needless to say I had my car taken in to have a remote start/alarm installed. I get the car back with bulbs blown out (not burnt) and car starts misfiring BAD. I replaced the coil...nothing. replaced the power transistor and it runs way better...

But now I still have a problem. My car still has random misfiring at idle and mostly under boost. When I stay out of boost it runs fine. But as soon as I hit 5psi+ it hesitates, has no power, jerks and almost sounds like backfiring. Is it possible my plugs fouled out? Or do you think this is a different issue??

 

[byebye_sti]

I recently had the same issue. Cylinders 1&4 had no spark. Needless to say I had my car taken in to have a remote start/alarm installed. I get the car back with bulbs blown out (not burnt) and car starts misfiring BAD. I replaced the coil...nothing. replaced the power transistor and it runs way better...

But now I still have a problem. My car still has random misfiring at idle and mostly under boost. When I stay out of boost it runs fine. But as soon as I hit 5psi+ it hesitates, has no power, jerks and almost sounds like backfiring. Is it possible my plugs fouled out? Or do you think this is a different issue??

Change/gap plugs first. If that doesn't fix it, check the resistance on your plug wires.

I'm having the same issue with my GVR4 - weak spark on cylinders 2&3. Going to replace the PTU and see if that fixes the problem.

 

[bq509]

Change/gap plugs first. If that doesn't fix it, check the resistance on your plug wires.

I'm having the same issue with my GVR4 - weak spark on cylinders 2&3. Going to replace the PTU and see if that fixes the problem.

Yea I replaced mine and it fixed it for the most part. Misfire under boost was due to the wire on cyl 1 being bad. It got drenched in oil and practically disintegrated. Once I changed out the plugs and wires she ran great again! Hopefully your issue gets fixed!

 

[byebye_sti]

Yea I replaced mine and it fixed it for the most part. Misfire under boost was due to the wire on cyl 1 being bad. It got drenched in oil and practically disintegrated. Once I changed out the plugs and wires she ran great again! Hopefully your issue gets fixed!

My car will start, warm up and idle high. When I shut the car off, it will not restart.

Were you having similar symptoms?