Misfiring continues...

[rendyx]

I thought that my misfiring problem was solved by reattaching a ground strap which had recently been removed. Not quite, as I found out later. Here's a list of my observations so far:

1. Misses started after upper 60k (I have Motorcraft plugs & wires), seemed to settle down, then started back up yesterday.
2. It seems to improve after running for a few minutes, and being lightly revved a couple times, or being driven. Occurs most often just after being started.
3. Driving does not seem at all affected by the missing, same with WOT. Both are smooth and powerful. It only misses at idle.

Now someone suggested that putting SDC on the DIS connectors could have caused it. Perhaps a poor connection there? I could also ground the DIS better. Rick (shojuan) mentioned using Artic Silver conductive heat sink compound behind the module. Considering I'm a computer overclocker myself, I have a tube of the stuff lying around somewhere. Still, it isn't highly conductive in terms of electricity, but somewhat.

Thanks for any help!

<small>[ February 17, 2003, 11:32 PM: Message edited by: rendyx ]</small>

 

[revhardSHO]

Have you run the codes? Thats the first thing you should do. And definatily check all the grounds! Bad grounds can cause all sorts of nasty little problems. Another thing you may want to try is disconnect your MAF. If your missfire goes away, chances are you have a bad MAF.

Chances are this is not your problem, but if i were you I would do the Idle Reset procedure (SDPatt did a write up on this, use the search function), just in case.

Have you cleaned your AIB valve? Perhaps thats not functioning correctly?

silas

 

[DougLee25]

Take a wire brush where the crossover tube bolts go. I had a miss fire once, and cleaning that solved the problem.

Doug

 

[rendyx]

No codes except the usual ACT (24) and knock sensor (25) ones last time I ran the codes. I'll try them again today, and maybe run the cyl. balance test a couple times.
I'll also be testing grounds, and I'll try it without the MAF. Along with that, I'll run the wires brush in there. I do have a spare around the house if needed.
We did the reset right after the upper 60k, and the IAB is new. However, something is causing an occassionally odd idle. I don't know if its the same problem causing the misfires or not.

Let me know if anyone alse has other ideas. I'm going to try and solve this problem once and for all today!

Another thought: would a temporarily missing crossover bolt (the ones from snakes->heads) cause this? One did snap when putting it back in (before I saw the warnings about torque!), and we didn't have the tools at the time to remove it.

<small>[ February 18, 2003, 08:56 AM: Message edited by: rendyx ]</small>

 

[SHOZ123]

Another thought: would a temporarily missing crossover bolt (the ones from snakes->heads) cause this?

If you have3 a vacuum leak at this spot it may show up as a miss at idle. Using some carb cleaner spray, soak the area down while it is idling and missing. It will temporally change the idle if there is a vacuum leak.

 

[AutoSHO]

rendyx:
No codes except the usual ACT (24) and knock sensor (25) ones last time I ran the codes. I'll try them again today, and maybe run the cyl. balance test a couple times.
I'll also be testing grounds, and I'll try it without the MAF. Along with that, I'll run the wires brush in there. I do have a spare around the house if needed.
We did the reset right after the upper 60k, and the IAB is new. However, something is causing an occassionally odd idle. I don't know if its the same problem causing the misfires or not.

Let me know if anyone alse has other ideas. I'm going to try and solve this problem once and for all today!

Another thought: would a temporarily missing crossover bolt (the ones from snakes->heads) cause this? One did snap when putting it back in (before I saw the warnings about torque!), and we didn't have the tools at the time to remove it.

It certainly isnt helping the situation to have that bolt broken. I would get that fixed. You must make sure you have a solid ground to work from. Try making a jumper wire from the DIS module to the battery (so you know for sure it is grounded) and see if that takes care of your idle problem.

 

[ScotSHO]

AutoSHO:

rendyx:
Another thought: would a temporarily missing crossover bolt (the ones from snakes->heads) cause this? One did snap when putting it back in (before I saw the warnings about torque!), and we didn't have the tools at the time to remove it.

It certainly isnt helping the situation to have that bolt broken. I would get that fixed. You must make sure you have a solid ground to work from. Try making a jumper wire from the DIS module to the battery (so you know for sure it is grounded) and see if that takes care of your idle problem.

I'm the **** who broke the bolt. tool I don't think that's causing his idle problem but I would try Paul's leak test to see if some air is sneaking by. I would clean all of the grounding surfaces and clean the DIS ground to the crossover tube.

Pat, if your grandfather has a good method for removing the broken bolt, I could come down and learn how to fix it. As in all fields of work, it's not how you avoid the mistakes but how you correct them! And I've got the first part (breaking stuff) down to an art!

Scot
95 MTX - 66k

 

[rendyx]

Scot Hewitt - 95 mtx:

AutoSHO:

rendyx:
Another thought: would a temporarily missing crossover bolt (the ones from snakes->heads) cause this? One did snap when putting it back in (before I saw the warnings about torque!), and we didn't have the tools at the time to remove it.

It certainly isnt helping the situation to have that bolt broken. I would get that fixed. You must make sure you have a solid ground to work from. Try making a jumper wire from the DIS module to the battery (so you know for sure it is grounded) and see if that takes care of your idle problem.

I'm the **** who broke the bolt. tool I don't think that's causing his idle problem but I would try Paul's leak test to see if some air is sneaking by. I would clean all of the grounding surfaces and clean the DIS ground to the crossover tube.

Pat, if your grandfather has a good method for removing the broken bolt, I could come down and learn how to fix it. As in all fields of work, it's not how you avoid the mistakes but how you correct them! And I've got the first part (breaking stuff) down to an art!

Scot
95 MTX - 66k

First, some news. I cleaned all the grounds, except for behind the DIS. I also cleaned up the SDC on the DIS connectors some. I put in another MAF, and no difference. I also played with the bolt hole a little (stuck my finger in it ), but it didn't do much. I haven't tried the carb cleaner test yet.

Scot, we may try those "Easy Out" things to get the bolt out, although I don't know if it will work or not. Basically, my grandpa said you drill a small hole in the bolt, then put in the easy out, and turn. It will attempt to remove the remains. That won't be today, though, as he's over at the doctor's, and I'm playing with my tranny fluid