And since both my SHOs are breaking at the same time... code 217?

[Huntervf]

The 93 has also developed an occasional bad running condition. Almost feels like the bucking of a cam sensor, but persists even at idle. Very sporadic--had it happen twice today during a 20-mile test drive, each instance lasted only a few seconds.

No CE light (which also had me thinking cam sensor), but I do have code 217 in memory-Primary circuit failure, ignition coil #3.

Problem with the coil pack maybe? Plugs and wires are close to having 60,000 on them, wells are dry so I really don't suspect that.

Thoughts?

 

[hawkeye18]

It's possible (bad coil pack). I would also check the EEC ground to the negative terminal. I had an occasional bucking that presented itself with a coil #2 code; long story short, it wasn't - the ground to the battery was almost broken and was intermittently losing contact.

The DIS could also be failing intermittently, but you can have those tested at an AAP/AZ (assuming they haven't lost the necessary connectors).

 

[SHO1]

The bucking thing is commonly caused by a bad/dirty MAF. unplug it and see if it goes away, may need cleaning or replacing.

 

[Huntervf]

That was the first thing I was going to do, until I found the 217 in memory. I actually replaced the MAF with a new OEM unit in 2007, only has around 25,000 highway miles on it. Still could be dirty, and if the problem continues, cleaning it is my next step.

AAP couldn't test the coil pack, but they did test the DIS. Ran the test four times, failed the first one, passed the remaining three. I returned home, did a DIS swap between the 89 and 93, drove the same routet as earlier and had no problems. Haven't tried driving the 89 yet with the "bad" DIS, I'll do that tomorrow.

Passing 3 of 4 tests matches up with the sporadic nature of the issue, and it also explains some of the other odd stumbling issues the car has displayed in the last few months. I was attributing them to the computer, which has been bouncing around with a fair amount of extra movement ever since it got an LPM waaaay back in 2005. Will report back after more testing tomorrow

 

[hawkeye18]

My 94 had a weird issue with intermittent stumbling that kept getting worse and worse until it got to the point where it was nearly undriveable, all in the span of about 30 minutes. Once it cooled down, it'd be ok again for another ~10 minutes, then the cycle would repeat.

Had the DIS tested, and it failed three times in a row. So I got a new one, and that one had sort of the same symptoms, only not as bad. So I swapped DISs with my wife's 95, and then my car acted fine... and so did hers. To this day I have no idea what the **** was going on there, but it worked so I wasn't about to mess with success.

Make sure you don't forget the heat sink paste when swapping DISs.

 

[Huntervf]

Well, swapped the modules, drove both cars today, and both run fine. I guess more time is required to see what happens.

 

[hawkeye18]

yeah, it seems that you're going through what I did. Damned if I know why that works, but uh... damned if I'm gonna mess with success.

 

[rubydist]

swapping them and having them work suggests some kind of intermittent connector issue to me.

 

[Huntervf]

Well, the plot thickened slightly today.


Put about 200 miles on the 89, nearly all trouble free until around the 130 mark (this was after the car had sat for most of the afternoon), when I noticed a high idle of around 1500 sitting still with the clutch pushed in. This is one of the occasional odd running/idling issues the 93 has exhibited for the past couple years. In almost 4000 miles of driving the 89, it has always idled fine. I fail to see how the DIS could affect this, but then my electrical wizardry generally leads to regional blackouts and another trip to the ER.

Tomorrow is the 93's turn for some miles--150 to be exact. We'll see how it does.

 

[rubydist]

if the DIS decided to increase the spark advance at idle, it could possibly raise the idle that much on a warm engine. probably make a cold engine run really poorly, but maybe it only happens with a hot DIS???

 

[Huntervf]

The tests at Advanced Auto actually had the DIS fail the first one, when cold. The subsequent three, with some temp in the module, were passes

But, if there's an intermittent problem, it could well have failed randomly once warm.

In any case, the 93 with the "good" DIS performed flawlessly yesterday. Even idled up better at cold startup. It's doing another 150 miles today, and then the 89 will do another 150 on Monday. Right now though, it looks as though a slightly malfunctioning DIS module may just be the culprit.