bad power transistor (another no spark thread)

[georgie2577]

hello fellow dsm friends.

This is regarding my 95 gs-t.

91 gsx is still running strong.

I was driving home and while pulling in second, the engine quits instantly. Felt like fuel cut but it never came up out of it. Further diagnosis reveals no spark on all 4 plugs. I checked for loose wires on all of the components that are responsible for spark and all plugs are dry and snug.

I'm testing the ignition module (power transistor or ptr) with the 1.5 volt AA and my results indicate that the 1-4 side is bad and the 2-3 side is good. Would this cause all 4 of the wires to lose spark?

George

 

[icedearth15]

I am not familiar with any of the testing procedures of these parts, but I had a similar problem as yours. I could be cruising in 3rd gear (steady load on engine) and all of a sudden I would hear a pop sound and the engine would hollow out, and a check engine light would appear. The only way to get the car back to normal was shut it off for 30 seconds or so and restart. I have had that problem for about 3 months...A buddy of mine suggested that we do a led pluse test to see what the check eninge light was. It came out to be a code 44 (1g dsm) and it had to do with the power transistor/coil packs. Well I replaced the Power TR Unit and it still happened...so I went ahead and replaced the coil packs and so far I havent had the problem since. The LED test procedure is shown on vfaq.com, I am not sure if it applies to the 2nd gens though (But you 2g guys can so a sequence before start up). Well I hope this helps!

Good Luck--Dave

 

[icedearth15]

Please disregard my coments on you having a second gen...I misread that portion of your post. Now knowing that you have a first gen I am confident that you had pretty much the same problem I had. Again--Good Luck

 

[georgie2577]

thanks for the help. I am having this problem on my second gen but its not displaying a check engine light when the key is in the on position.

 

[georgie2577]

Since the Power transistor tested defective, I decided to replace it with a new one hoping it would fix my problem and unfortunately the problem still exists. SUCKS I intend on fixing this problem myself and will continue to update this thread until it is complete.

My motivation for this is simply because I have researched this site for hours using various keywords and I always find threads that are incomplete. Maybe I will create a trend.

My next step will be to test the Crank angle sensor. I was trying to find the camshaft sensor on this model and couldnt find it. Can someone elaborate on the 95 gs-t cam sensor. Is it replaced by the crank sensor?

G

UPDATE 1A

I pulled the top ignition coil connector and tested for power with a test light on the middle terminal with the ignition key switched to on. With the switch on there is power to the coil. I proceeded to turn the ignition and while the engine is turning over I have a pulsing light. Does this mean the rest of the system (crank sensor, ptr, ecu) is functioning correctly? I have decided to take the coil off for further inspection and I must say it is being a bit stubborn to get out. Does the fuel rail have to come off?

G

 

[icedearth15]

Yes the fuel rail, when off, will make it easier to remove the coil packs. Also, when the section of the wiring harness that runs in front of the intake manifold is lossened it only makes more room to get them out.

 

[georgie2577]

Fuel rail is off. dropped a few peices... crap!

got the coil out and its testing bad too. Im running low on funds so I might have to wait a while till I update this post. I will have some more information soon.

G

 

[georgie2577]

As it turns out, I was testing the coil wrong. The coil is in fact within resistance tolerances and therefore is good.

So ... Does a 95 GS-T have a camshaft position sensor? If so. Where is it?

geo

 

[luv2rallye]

As it turns out, I was testing the coil wrong. The coil is in fact within resistance tolerances and therefore is good.

So ... Does a 95 GS-T have a camshaft position sensor? If so. Where is it?

geo

At the passenger side end of the intake camshaft.

Note that a coil can sometimes still be bad even if it's resistance is ok - especially since you say "while the engine is turning over I have a pulsing light" on it's connector (which you should have).

 

[georgie2577]

At the passenger side end of the intake camshaft.

Note that a coil can sometimes still be bad even if it's resistance is ok - especially since you say "while the engine is turning over I have a pulsing light" on it's connector (which you should have).

Cool. Thats where I've been looking but theres nothing there. I have a 91 gsx and it has a Cam Angle Sensor in that area but not on my 95 gs-t.

Hey Rally, the fact that I have voltage to the coil and that its pulses when I turn the ignition is a good thing right?

Jeez these coils are expensive..

 

[luv2rallye]

Well on my 99 GST it's there - it bolts in from the rear. Maybe they just forgot yours
And yes that's a good thing.

 

[georgie2577]

::my back hurts::

I found my cam sensor. its right behind the intake timing belt sprocket. theres no indication of its location in my chilton or haynes manuals. sucks. Im getting 12 volts right to the cam sensor and 12 volts to the crank sensor. I dont exactly know how to test the actual sensor. I've done some searches and have come up empty. Anybody know if the 91 gsx coil pack will work on my 95 gs-t? sure would be a good test.

g