What the duece?!?

[SuperHO]

Aighty, now I'm mad.....that damn 93 that I told y'all about in a previous thread is back again....

for those of you who aren't up to speed, allow me to elaborate:
I got a 93 ATX from my uncle-in-law cuz he said it needed a tune-up. And boy did it ever. The car has 135,*** on the odometer and had the factory spark plugs and wires. let me repeat....F.A.C.T.O.R.Y. plugs and wires. they'd never been changed....for that matter, the only thing that'd ever been changed on that car is the oil, tires and...well, that's it. this car was a wreck. So I went through thouroughly doing the following:

upper and front 60k
new plugs (Bosch Platinums)
New wires (same ones I got on my car..brand unknown)
new CKP & CPS
new water pump
new fuel pressure regulator
new fuel filter
new O2 sensors
new EGR valve

and probably abunch of other stuff that I can't remember off the top of my head thanks to copious amounts of medications.

Anywho, after all that, the car was still misfiring. I sat and did diagnoses using my parts off my wife's car, to no avail. The wife has a 94 ATX, by the way. So now all those new parts are on my wife's car, and the 93 has parts I KNOW work (and the wife's car's running fine except an insufficient EGR flow code). The only code the 93's throwing is for O2 sensors, which makes no sense cuz they're brand new. Now, the car is currently sitting at a high school shop class letting them play with it. The best they can do is telling me that the #2 and #5 cylinders are misfiring. The shop teacher at first thought it was a coil pack.....but then we reminded him that the coil pack that was on the car when it was misfiring is currently doing duty efforlessly in my wife's 94. Everyone keeps saying the plugs are the culprit, but does that seem too coincidental that a shared set of cylinders are misfiring? That, and neither my modded 92 nor my wife's stock 94 have ANY problem at all using the same plugs and wires as is in the 93. I've heard of SHOs being finicky, but damn...c'mon!

So....can anyone offer any sage advice before I moltov cocktail this car into oblivion?

 

[1stSHO]

Try this, sounds like what mine did. Make sure you look at the coil pack carfully

 

[SuperHO]

I checked that more times than I care to count (or could remember even if I did), and the school said they swapped the wires, too, just to make sure, with no effect.

 

[SASHO91]

sounds like a bad DIS, coil pack.... maybe faulty???
have you checked the spout connector?? it may be unpluged.... its a shot... check both of them.....

what wires are you using? plugs??
also check to make sure there is enough di-electric grease on the dis... and check your grounds....
thats all i can think of.... good luck hunting it down...

 

[Shoaz]

Have you checked the injectors? Try running the KOER test, especially the cylinder balance.

 

[Off Road SHO]

The coil pack might not be bad but the wires that "fire" it might be. There are three, all yellow with a different stripe for each pair of coils. They go to the DIS via a shielded bundle I believe. If there is corrosion in the wire bundle or the DIS connector on one of those yellows, you will probably get a misfire on that pair of cylinders.

Tom

 

[SuperHO]

The coil pack might not be bad but the wires that "fire" it might be. There are three, all yellow with a different stripe for each pair of coils. They go to the DIS via a shielded bundle I believe. If there is corrosion in the wire bundle or the DIS connector on one of those yellows, you will probably get a misfire on that pair of cylinders.

Tom

That's something I haven't thought of yet. I've not quite got the hang of a KOER test yet...I've always done em with the engine off......::shrugz::

Someone wanna tell me how I can do that and check the cylinder balance?

 

[Racer X]

I just went through that with my car. $20 says that it's the DIS. My misfire began intermittantly, and then became persistant. I picked up the Wells DIS from AutoZone (along with a short prayer that it too doesn't fail on me), and so far all is well.

If anything, try swapping DIS's between the two cars and see what happens. The screws are 5.5mm; don't overtighten them.

 

[SuperHO]

I did....the DIS module (brand new, by the way) that I put on his car is now on my 92. I've played musical chairs with every sensor that I cared to yank off that car....with either my wife's 94 or my 92 as a guinea pig.

 

[Off Road SHO]

I did....the DIS module (brand new, by the way) that I put on his car is now on my 92. I've played musical chairs with every sensor that I cared to yank off that car....with either my wife's 94 or my 92 as a guinea pig.

But not the engine bay wiring harness. Give a firm tug on all of the wires going into all of the harness plugs. Also look for telltale signs of corrosion (whitish powder) around any of the connectors (pin end and wire end).

Tom

 

[shonutt]

did you think to check the intake runners and make sure they are down even and not cocked funny i did this before and had a hard time keeping it running it felt like a missfire and it created a vacleak pulled off the manifold made sure they went into the grooves probolem solved

 

[SuperHO]

did you think to check the intake runners and make sure they are down even and not cocked funny i did this before and had a hard time keeping it running it felt like a missfire and it created a vacleak pulled off the manifold made sure they went into the grooves probolem solved

Yep. That was one of the first things I checked, but it went down just fine. It's been off three times since then, and all three times I've made sure it was properly secured.