Another 93 ATX w/ Misfire Issues - PLEASE HELP!

[93_SHO_FL]

Ok, so I've been reading and found alot of misfire threads. All are similar, but not exact to my symptoms. I did find one that closest resembles mine however here - http://www.shoforum.com/showthread.php?t=113212

Here's the parts I have replaced prior to reading the thread above.

D4U1 95 EEC-IV Computer (on 2nd one, this one is from RCM Auto), Bosch O2 sensors (still need to replace the rear one), Fuel Tank, Fuel pump & sending unit, Fuel filter, MAF, DIS, EGR Valve, EGR Sensor, Coil Pack, new Autolite Platinum plugs last night, & bought a Cam position sensor today, will be installing this evening. I put a new 850 CCA battery in a few months back also, and it tests out fine, as does my alternator.

I just did the Idle reset procedure I found on here that is as follows:

Idle Speed Program Reset Procedure
-----------------------------------------
1) Disconnect the negative battery terminal.
....Optionally, disconnect the keep alive memory (KAM) connector in the small
....wire also landed to the negative battery terminal.
2) Wait at least 30 seconds.
4) Reconnect the KAM connector or negative battery terminal.
5) Start engine normally (never press the gas pedal).
6) Allow the idle speed to settle for at least 30 seconds.
7) Within 70 seconds of starting the engine, concurrently apply all accessory loads.
....a) Climate control to MAX A/C.
....b) Headlight switch ON, brights ON.
....c) Turn steering wheel slowly ~1/4 turn side to side.
....d) Press brake pedal.
....e) ATX SHOs only: shifter to DRIVE.
8) Do not turn off engine for at least 5 minutes.

----------------------------------------------------------------------

That seemed to help keep it from wanting to stall out, but still misfiring.

I have made some videos that I thought may help also. I don't want to tear into the engine if I don't need to. From the thread above, it very well could be a shim. I'm going to start on it this evening, luckily I have 3 day weekend, but I'd rather not spend it working on the SHO.


Here's the videos I made about 30 min ago.

Video List


I welcome any and all suggestions! I will try to check my email often during the process, but being that I just sold my laptop (was going to by a Xoom til the car acted up), I have to use my Droid or go inside to use my PC to check it.

I got it to scan on my friends SnapOn MODIS scanner one time in KOER mode, but KOEO didn't scan, and it wouldn't clear codes, nor would it scan after that. This is why I initially thought I was chasing electrical gremlins.

The one time the scanner worked, it came back with no codes, all items passed. This was with the CEL on solid & misfiring like a mo fo.

When I swapped the EEC out, I got a 95 tested unit from RCM, and I had battery disconnected when I put it in, and left disconnected overnight to make sure it totally drained. I have been driving it daily for about 3 days, and it progressively gets worse. I put new plugs in it last night, but same result. The wires look fine, and are supposedly about 6 months old (Autolite). I considered changing these as well (but waiting).

I went with the 95 EEC unit at the advice of the people on this forum to help with the 93 ATX issues.

I also had smoke test done, and found 1 vacuum leak. I fixed this. Now there are none. Also, my AC now flips to MAX AC on RECIRC mode instead of fresh air mode. So that vacuum leak must control that part. ;-)

If you could, watch my videos (sorry they're from my cell phone) and maybe that can help lead me in a better direction.

Thank you in advance for help you all can provide me with.

 

[RAYJAY]

Did you have the intake off ? If so you may have a line or wire pinched under the intake, or if you cleaned the intake did you replace all of the gaskets???

 

[93_SHO_FL]

Have not taken intake off yet. Am about to though.

 

[RAYJAY]

it may also be the rubber connector on the intake if they leak it will cause a stumble,

ok after looking at the vids...... are they still the factory wires ????? and why do you have the vac line plugged with a screw on the vids?????

if you changed the plugs what did you use??? brand and numbers

 

[93_SHO_FL]

Ok, spent last night messing with it. It ended up being vacuum and fuel issue.
The hose coming off the top of the IAC area was plugged with a screw by previous owner...*******.
I found out why...the canister purge solenoid was broken so he bypassed it but didn't complete the vacuum flow. Once I re-bypassed the solenoid and removed it, it got much better. I also installed the rear o2 sensor as well. Did idle reset 3 times until it finally starting running better.
It still has a slight miss, but doesn't fall on its face under power now. Swapped eatc and the heat doesn't come on sporadically anymore either...which is nice in florida. Lol
Also pulled the cam position sensor and the PO had RTV'ed it on and got a dab of silicone olright smack dab in the center of the sensor area. TARD!!! So I replaced it with a new one...old one had a little oil in it...should I worry? I cleaned it out before installing new one.


I did some testing and noticed when I pull the hose for the fuel pressure regulator, the car idle jumps a little and mellows out. I plug it back in and it kinda stumbles again. Could this be bad? Id rather not spend the $73 on it if I don't have to.

The car runs 200% better now...even with AC on full blast.

Thanks for the replies. I still would like to k.ow why this things wont scan codes, and why it has a slight mistier still.
Do I need to put new purge valve solenoid in, or am I ok without it?

 

[93_SHO_FL]

It's back to running weird again. It runs about 85-90% with AC off...but then about 40% with AC on.
Seems to be ok while driving...ac off.
Running on 5-cyl while driving...ac on.

Checked all vacuum lines, grounds etc. Nothing odd.

Maybe one of my fans is going bad? Drawing too much current so when compressor kicks on, it kills electrical system??

Anyone local to me in Clearwater that wouldn't mind looking at her for me?

 

[93_SHO_FL]

Well, the car seems to be about 90-95% now. I can live with that...especially considering she's got 177K on her clock.

AC still turns off and heat comes on automatically randomly. Changed out EATC...same thing. Not sure what else would cause that. It's not the compressor just turning off, that actually stays engaged...and the actual heat turns on. Sometimes its for a minute or 5, other times, I have to either turn ignition off and on again, or run the EATC self diag. Then it's ok and ice cold again...until the next time...which could be 2 minutes, could be 2 hours. FRUSTRATED!!!

The PCM has adjusted the idle now though. It idles at around 700-900 with AC on or off. YIPPEE!!! Occasionaly dip and miss with lights, wipers, ac, in gear, brake lights, etc all on...prolly an alternator dying or something.

Any help with the strange ac/heat issue is greating appreciated though.

Also, the little hollow nuts that hold the vacuum lines on the back of the EATC...anyone know where to get these, or have any laying around? They are the same ones that hold the lower console/cassette/cig lighter tray in place. I am missing all 4.
Thanks.
Anyone?