Yearly DIS Module Problem........

CMac89

Registered User
Every year, plus or minus a week (literally), I have either a DIS module go bad or it just needs more heat sink compound added to it.

The signs are not gradual nor does it give me any hints there is a problem. It just starts stumbling real bad and won't run.

Tonight I was laying the smack down on an old Kawasaki 750 motorcylce then whenever I got to a friends house it started stumbling and died. Completely random.

What would cause a DIS to go bad to where it would only last for a year? Two years ago, it happened and I had no clue why. Whenever I figured out it was the DIS I knew what it was the second time it went out, last year, which was a week from the same exact date just a year later. Now, the week before the shootout like last year, I am having the same DIS problem.

I had to leave the car at a friends, so I don't know if the DIS is bad or if it just needs more heat sink. I guess I'll find out.
 
Every year, plus or minus a week (literally), I have either a DIS module go bad or it just needs more heat sink compound added to it.

The signs are not gradual nor does it give me any hints there is a problem. It just starts stumbling real bad and won't run.

Tonight I was laying the smack down on an old Kawasaki 750 motorcylce then whenever I got to a friends house it started stumbling and died. Completely random.

What would cause a DIS to go bad to where it would only last for a year? Two years ago, it happened and I had no clue why. Whenever I figured out it was the DIS I knew what it was the second time it went out, last year, which was a week from the same exact date just a year later. Now, the week before the shootout like last year, I am having the same DIS problem.

I had to leave the car at a friends, so I don't know if the DIS is bad or if it just needs more heat sink. I guess I'll find out.

I had a bad stumble issue a couple of years ago on my 90. Actually it was more like a flying trip face first wipe out into a pile of horse manure :D. Car ran like chit. This all happen the day after I went to a 10% blower pulley.

I’ve actually experienced a bad DIS and it’s not the same problem as I had. CEL came on and the TAC was jumping up and down like a Mexican Jumping Bean.

I had no CEL so pulling codes was useless.

I ended up rebuilding the intake system with new gaskets and hoses, rebuilding the injectors, and changing my plugs and wires.

Have you noticed that your CEL lights up prior to the problem occurring? Do you get a CEL light during the problem?

My experience has been if the DIS over heats, it will malfunction until it cools down. I'm assuming that you let the engine cool and tried it again and it still has a problem.

If you're getting a CEL I'd pull the codes before replacing any parts.

If you’re not getting a CEL then you may have developed a bad intake or vacuum leak.

Heat Sink compound is cheap so I'd get a good known brand.
 
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Same thing here for the past couple of years. I ended up going and buying a new one at a parts store that has a lifetime warranty. If it goes bad, they give you a new one. Still doesn't help solve what causes them to go bad quickly.
 
Make sure the bottom of your dis is polished up and flat.
Also clean up the mounting surface of the DIS.
Use Artic Silver heatsink compound ( available at computer stores )
Its better than the white "bird poop" they sell at Radio Shack.
A uniform all over thin coating is what you need, not a whole bunch.
Torque the Dis down evenly.

Ive even thought about making a finned heasink for this crazy DIS behavior!

Good Luck
 
No, there are no check engine lights.

I went over today with a tube of heat sink compound. Whenever I got there I tried to start it up and it was still running badly. I took the DIS off and put some new heat sink on, put it back together, and it ran much better. However, it still missed out. Swapped out to another DIS I had, ran like crap, and then swapped back to the one I had on, and it ran like crap. At this point the motor was around 160 or so. Had it running for a bit whenever it was more clear.

SOOOOO.........since it's about the fourth time this has happened to me, and the only thing I am tampering with is responding, I know it's the DIS module.

Since it happens once a year, I went ahead and bought one from O'Reilly Auto Parts for $105 with a lifetime warranty. I'm going to try the new one out tomorrow, then see what happens from there.

I have always run bird poop from Radio Shack and it works out well. Not to mention I don't really feel like looking for a computers store just to find some special stuff. T

hanks for the input.:)
 
DIS modules shouldn't fail like that and heat sink compound isn't a magic bullet. I would check all the wiring that goes into the dis and check the wiring at the coil pack. I would check the resistance on the coils to make sure they are all the same. It's possible for a coil to act up in a way that creates extra work for a DIS, leading to it's early failure. There is an old thread somewhere that went through a lengthy diagnosis that ended up being a coil pack leading to DIS failures.
 
DIS modules shouldn't fail like that and heat sink compound isn't a magic bullet. I would check all the wiring that goes into the dis and check the wiring at the coil pack. I would check the resistance on the coils to make sure they are all the same. It's possible for a coil to act up in a way that creates extra work for a DIS, leading to it's early failure. There is an old thread somewhere that went through a lengthy diagnosis that ended up being a coil pack leading to DIS failures.

Interesting, Mike. Thanks for the input.

I do, however, have had another problem that happened two or three times this year.

One day, I got out of work and my car wouldn't start. So I took a spark plug wire off, and held it by the negative terminal of the battery to check for spark. Whenever I turned the motor over, it arched against the negative terminal and then the motor started.

After that day, the same thing happened four months later, then again a week later, now it hasn't done that since. I've checked everything that doesn't need to be swapped out. Not to mention, there's not way for me to diagnose it, if it's working at the time. That's a separate problem, I believe.
 
There is a post about voltage drop in the wiring between the DIS and the coil pack. If I remember correctly, It says the volage signals are so low that any voltage drop from contact corrison will cause problems.

My wiring harness was dripping with oil from a long term leaking snout seal, so I unwrapped it and redressed it. If you open that harness up, be carefull to mess up the foil that shields the wiring.

I got tired of chasing my tail, and replaced the DIS,Coil Pack, and cam sensor, along with cleaning up the harness.---fixed it.

Advance auto can check your DIS, and some Autozones can (or will)

Good luck
 
Interesting, Mike. Thanks for the input.

...
After that day, the same thing happened four months later, then again a week later, now it hasn't done that since. I've checked everything that doesn't need to be swapped out. Not to mention, there's not way for me to diagnose it, if it's working at the time. That's a separate problem, I believe.


Perhaps. Here is the thread I was talking about. you might want to go through some of the diagnostics that were recommended in there.
http://www.sccoa.com/forums/showthread.php?t=36706&highlight=dis+coil+pack
 
the previous owner to mar car said it would stumble and sometimes not start. So he replaced the camshaft sensor and it still acted up so then he bought the new dis and my car runs good now except for everyonce in a while when i start it it stumbles untill i give her gas then she runs fine the whole rest of the day. I put an aftermarket cai on it that goes down to the fender and from it being so s hitty and not mounting correctly a whole got worn through it so now it sucks up unmetered air. Im guessing that this is my current problem.
 
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