Hey guys, I have a rather complex issue that I hope we can figure out. Here's the story. I'll try to keep it short, but lose no details.

While driving on the highway, my torque converter lockup will disengage for what seems like no reason. This forces me to have to apply more gas to maintain my current speed (ex. 70mph). It also is evident by the fact that when in lockup, I run at about 2100rpm and it barely increases when i give it more gas (meaning the torque converter is in 'lockup mode'. When it disengages, my RPMs will increase to about 2400 on level ground - just to maintain 70mph - and will increase to almost 3000 on a very simple slope, just to maintain speed. Enough with the boring stuff: here comes the fun information.

I have an HTC EVO, and found this Android app named Torque. With an ELM-327 bluetooth adapter I purchased from eBay, I can actually turn on the app, wait for it to connector to the bluetooth adapter, and read some live data from my Monte's computer, as well as read fault codes and clear them. It's a really cool setup for just under $35 total (~$30 for the adapter, $5 for the app). Now, when I am driving, I have a misfire on cylinders 1 and 4 (worst), then the others will misfire at times as well. I've changed plugs and wires, cleaned the contacts on the ICM that the coils slide onto, and still won't stop misfiring. Now, when the torque converter disengages from lockup, the Torque app does not find any fault codes, but, if I send a 'clear fault code' command to the computer, I instantly get my lockup back!

What I have changed so far:
plugs (installed Bosch Plat 4's)
wireset
- cleaned terminals for all coil packs
- swapped 1/4 coil with another 1/4 coil with no fix in misfire.

What my questions are:
1) Why would I regain lockup as soon as 'clear fault code' command is sent to computer?

2) Will an almost constant misfire (on cylinder 1 if it matters which cyl.) cause my torque converter to disengage from lockup?

3) If it's not my plus or wires that's causing a misfire on cyl. 1 & 4, and often times 2 and 6, could it be a fauly ICM?

4) do you think it will be ok if I purchased coil packs and ICM from ebay? I found a full set of coil packs for ~$40, and an ICM for $40 as well.

 

swapped the 1/4 coil that I got from my father in law with my original one and misfire did not change. I am assuming this means that I either have a bad ICM or a few bad injectors.

 

I also have the torque app on my Commando, VERY handy, but i'm looking at getting a hard-wired adapter because i need to know instantly if my car is getting knock and the 327 is too slow for me, but it is soooo handy for getting codes and minor scanning

The lockup disengaging on you is from the misfire code being active in the pcm, which is good, when a misfire is detected the engine is not running smoothly producing vibrations, if the converter stayed locked it would send those vibrations through the torque converter and trans to the wheels making the car jerk and eventually cause trans/converter/differential/wheel bearing/CV shaft problems

on to the topic of the cause of the misfire:

well first off take those platinums out and smash them to bits, then smash them to even smaller bits, repeat several times until nothing remains. If your car is stock get a set of stock AC Delco plugs, or another iridium tipped plug of the same heat range, AC delco plugs are just rebranded NGK's now so NGK's would be a good choice, Autolites are made in china now and fail constantly... if the car is mildly modified (intake and/or exhaust) or if you just drive hard a set of NGK TR6IX plugs would do you good. Also when you put the plugs in be very careful not to crack the ceramic or you'll have issues very similar to what you have now. If you hear a crack when you put them in you've cracked the ceramic and the plug needs to be replaced


First thing first, 1 and 4 are on the same circuit and it would make sense that if one misfires because of an issue in that circuit the other would too, you can try another set of plug wires which will most likely fix the problem


after that has been done, if the misfire continues i would try another ICM, then if it's still there i would shuffle the injectors, if the misfire moves with the injectors you solved the mystery


and as for whether or not to get your ignition stuff from ebay.... i wouldn't, i'd just go for a used set from a junkyard and clean them up

 

UPDATE:

I waited a couple days for replies on this thread and didn't get any, so at the time I went ahead and ordered a new ICM and 3 new coils from a company in Florida. I waited a whole week, got the parts, and the ICM made my engine fire so badly I had rotten egg/sulfur smell coming from the tailpipe and misfires on 5 out of 6 cylinders. So, I removed the new ICM, put the old one back on, put the new coils onto the old ICM, and I ran like a champ.

That is, until I made my trip to Cleveland, which is 60 miles. I now misfire on 3 cylinders - 1, 4, and 2. This problem is like a disease that's slowly eating my engine from the front of it to the back.I'm not sure what to do now. I searched all over the Pull A Part in Cleveland for a MAF and fuel injectors that are the same style as mine, and I had absolutely no luck. My injectors are skinny with one flat side on them, and all the ones I could find on any 3.8's were fat, barrel-style injectors. I have a couple in my garage somewhere, time to dig them out.

I've worked this whole thing out in my head and here's my best explanation of my problem.

-- When I start the car and idle it, it runs smooth. My Torque app shows 0 misfires.
-- When I first begin driving it, it seems to run ok, no misfires.
-- Torque converter lockup disengages itself whenever the engine has low load/high speed (ie barely giving it gas while cruising at 61-62+ MPH)
-- During low-load periods (where I'm cruising on level or downhill road, I begin misfiring, sometimes noticeably. Most of the time, my misfire count increases by almost 100 every 2 seconds, I lose TCL (torque converter lockup), and my engine light occasionally blinks.
-- Torque Converter lockup will remain engaged all the way up hills, where engine load is higher.

INFO -- Normally, I wait a couple minutes after starting it to hop onto the highway (which is what i always do).
INFO -- When I send clear fault codes command (even though no fault codes appear aside from misfire codes on occasion) TCL re-engage almost immediately and will remain engaged if I keep "medium" load on the engine (ie going uphill, giving it more than just a little gas).
INFO -- ALSO, important, is the fact that once the TCL disengages the first time, it's hard to keep it engaged when I send the clear fault code command. Even when not misfiring (that I know of) I'll lose lockup if engine has low load.