2G Very weak spark on 2/3

[Tanro]

I've got new plugs, wires, and coils. Doesn't matter if I swap wires, plugs, or the coil between 1/4 and 2/3 I still have weak as shit spark on 2/3. The HT Leads won't ark to a ground them selves. and I have to put a spark checker in them and touch it to ground get any spark. However the 1/4 HT leads will arc to ground readily. And arc to the spark checker without inserting it. The arc is much brighter when the spark checker is fully inserted than with the 2/3.

This is leading to some very rough idling when cold, and some partial throttle hesitation when warmed up. Above 4000 rpm I have no issues with spark.

I am leaning towards replacing the ignition module (PTU). But as they are over 100$ from the parts store I don't wanna waste my money if I might have other diagnostic steps to complete.

 

[Spideydsm99]

Try testing the ptu. If it's bad I got one I'll give to you.

http://www.dsmtuners.com/threads/how-to-test-the-power-transistors.229419/

 

[Tanro]

Thanks for the link, gonna test it out now.

Here is 1/4(pins 7&8) bulb is quite a dimmer.

You must be logged in to view this image or video.

Then 2/3 (pins 1&2)

You must be logged in to view this image or video.

Considering I have a 2gb with the cam sensor on the pass side of the head, and I have the same firing order as a 1g, I think those are actually reversed.

Either way, it seems the PTU is going bad.

 

[Spideydsm99]

@Tanro let me know if you want a used one. I'll send it just pay shipping.

 

[AlexGsxCummins]

Please let me know of you fix this, ive had the exact same problem, mines on 1 and 3... Very weak car will hesitate when first started and intermediate when cruising and given slight throttle. Really annoying ive been throwing money everywhere ive just been greedy knowing I have a ptu in storage just cant find it.

 

[Tanro]

Yeah I got a used one locally, made it worse. Going to get a new one.

 

[AlexGsxCummins]

Weird when I bought a new one from O'Reilly it made my problem worse too it was only running on 2 or 3 cylinders so I returned it

 

[AlexGsxCummins]

Any chance you have tried the alternator? I was going to try that next looks like so far we have both replaced the same parts chasing this issue...

 

[Tanro]

I replaced my original PTU with an Oreilly's (import direct) PTU. Seems to have greatly helped my spark issues.

It seems now the only spark issues I have are when the alternator belt is slipping at first start. (Yeah I plan to tighten it this weekend when I get around to bolting down the Oreilly's ptu) and some misfiring due to state of tune and boost leak(s) I know I need new injector seals.

I no longer have problems with weak spark on 2/3. And the cold start issue has seemed to be mostly alleviated. Though it does still do it. So I will try to remember to update this in the future as I make further repairs/replacements. I know this car has about 10 years of neglected maintenance that needs to be taken care of...

 

[Tanro]

Any chance you have tried the alternator? I was going to try that next looks like so far we have both replaced the same parts chasing this issue...

My alternator was causing me issues for quite a time. It was barely charging. and the problem was worse in higher RPMs. It was also shorting internally and causing my pc680 battery to drain to about 2v in 10 hours. Eventually it shit out completely and was not charging at all. I ended up replacing it with an advance autoparts alternator with lifetime warranty. Voltage is rock steady as I also ran a 8 gauge charge wire with full copper welding lugs at the same time.

 

[AlexGsxCummins]

Well I tried the PTU and for me it did not help, with the same issues as the OP. Ive also replaced the same parts, plugs, wires, coil, PTU. Now I have a galant alt on its way..i read on 2 other posts it cured there issue so I will report back.

 

[Tanro]

Had a burnt, corroded wire on my coil pack harness that the dipshit previous owner just wrapped tape around.

Rewired coil pack and misfire is gone now. I used 14awg wire just to be safe.