No.1 cylinder no spark/weak

[90turboturd]

Hey guys, I have a 90 GSX with a 16g. The other day i was on the highway and hit a pothole pretty hard,after that it sounded like it was only running on 3 cylinders and my vacuum dropped to 10.I pulled the plugs and found that number 1 plug was soaked in fuel. Replaced coil,plugs and wires and still have the same problem,checked for vacuum leaks found none but i have a exhaust leak by the manifold and head. I'm completly stumped and would greatly appreciate it if someone can help me out. Thanks

 

[EagleTalon1993]

Does the number one plug wire have spark ? If it does then I would do a compression check on the number one cylinder if not check the ignition module connector make sure it wasn't jarred loose by the impact. If everthing else checks out then I would guess with the vacume dropping so far a valve may be sticking open or not seating.

 

[90turboturd]

it has a very weak spark,i checked all my connections and they were fine. I noticed my power transistor bracket was loose, would you know if it grounds itself?

 

[EagleTalon1993]

Ground is very improtant for the module it may short if not well grounded I added an extra ground wire from the bottom bolt securing the module to the firewall on mine and no problems since (after I replaced the module).

 

[90turboturd]

Would you think a bad ground would cause one cylinder to not fire?

 

[719_dsmgsx]

Ya for sure, I had a similar problem. I pulled it out and it was all burnt up.
I would check it first, so u won't have to drop too much money

 

[90turboturd]

what did you pull out that was burnt up , the plug or the coil pack? I already swapped coil packs,wires and plugs, plus Im horrible with electrical so Im at a loss with it.

 

[rush2252]

Did you perform a compression check? If its still weak spark look into the CAS. Read up on how it functions it can give you issues on ONE coil pack. If its only ONE cylinder I would look into power transistor or wiring.

 

[90turboturd]

No I haven't done a compression test yet,I'm trying to see if one of the guys I work with will let me borrow one. I have a feeling the power transistor went out,I dont know if I should order that straight from Mitsu at work or go to advanced..

 

[EagleTalon1993]

I got a power transistor at a local salvage yard taking a chance that it was good but the price was right and they gave me a 30 day money back guarantee and I got lucky it worked.

Have you pulled the transistor out and done the old visual inspection ?

 

[90turboturd]

Thats not a bad idea, does it have to be off the same model or can it be NT 1g? I pulled it out, nothing seemed out of the ordinary.

 

[EagleTalon1993]

I would pull it off the closest model I could find and it will have some numbers on it that you should match up with the replacement. If you can, have someone take you there so you can bring the old one with you to match the numbers.

 

[bigf4]

junk yard is a great place to find cheap parts. sometimes

 

[90turboturd]

Well I'm going to try it, but I doubt they will have it.Most junkyards around here that have gsx's are already stripped down..

 

[92awddsm]

Well I'm going to try it, but I doubt they will have it.Most junkyards around here that have gsx's are already stripped down..

Well, the 90 transistor was different than the 91 and up. Chances are, you will have to buy a new one from mitsu or used off of the classifieds. Unless you get lucky and find a 90 in the jy.

 

[90turboturd]

So after my long quest,couldnt find any in a junk yard.Advanced has OE for $96 but it's going to take a week to arrive.Hopefully this works..