Anybody heard of a DTC code 58? It'* not listed in my 93 manual. I salvaged a PCM from a 92 and swapped my "chip" to it. So, this may be a 92 code (maybe?).
- Reason for trying this PCM was I had a "no start" situation and unplugging & replugging PCM plugs fixed. So tried this 92 PCM I had. But it threw codes, so the original is back in.

Update on my Code 42: After sitting for 5 days, my battery completely died & would not charge. Also, the negative terminal was getting loose from disconnecting so many times to clear codes.
The new battery seems like a magic potion. No codes in the original PCM, but waiting for a Delco O2 sensor from Rockauto tomorrow in hopes of clearing up the "crappy" spot in accelerating.
thanks

Get the proper prom. Code 58 is a phantom code that all 92'* have.

There are differences in the 92 PCM (prom) that will not allow a 93 to run properly.

I had swapped the chip from the 93 to the 92 when I tried it. (It wouldn't even run when I tried it with the 92 chip). Anyway, cool; guess I can ignore the 58.
Thanks Willwren

Installed the Delco O2 sensor from RockAuto last night. It seems that the hesitation is only about half as bad. Still NOT throwing any codes. I'm delaying judgment on the codes, though. Doesn't seem to be running as rich as before either (smell). Wife is back to driving it the short haul to work as a mini-test.

Guess it' must be a combination of things on that hesitation (aka "crappy spot"). Will try replacing some vacuum lines that are brittle and slightly cracked. Also, there are a couple of "U" shaped vacuum lines right at the source on the TB.
Are those hard to find?

Will take a look at the plugs too. I found my records and they have 10K on them & the Belkin cables. Plugs are Champion Platinums gapped at .060.
Any problems w/running those? (NOT SC)

Thanks

Belay that statement. "42" is baaackkk. Then not. Then Back. Okay, okay... I'll dive into replacing that ICM wiring harness on Friday. Yeh, yeh.. I'm a believer.. "Wiring & Connectors."

Just keeping track of the latest work.
A. Replaced the ICM harness (with crank & cam sensor plugs) w/8-way plug with one from the yard.
B. Also found the (3 wire) ground near the alternator to be somewhat loose again. Really tightened it up this time.
C. Replaced 4 pieces of vacuum line.

Not throwing codes yet. Will be driving more this week to see if that comes back.
Still runs rough / cuts out when trying to accelerate above a gentle cruise of 40-45.

D. Pulled Champion platinum plugs and inspected. With exception of #1, and maybe #2, they look typical for 9K miles. Electrodes are clean/gray, with slight tan color at tip. However, #1 is tan almost all the way to threads. #2 is not that bad, but is tan, maybe half way down.
E. Added two 12oz bottles of Chevron Techtron (sp) in full tank, in hopes of cleaning up the injectors. Not enough time for these to do any good yet.

I am now thoroughly convinced that I won't find the cause of the sputtering, stumbling, spitting until I have found and fixed every other, stinking problem and there must be a boat load of them. Driving me to drinki

I fixed the problem of the lights dimming and volts dropping when I would rev it or accelerate hard (same time as the sputtering). It was the ALTERNATOR. I theorized that the voltage regulator was over-reacting at revs and clamping down the output too much. It bench tested okay (at idle speed), but if nothing else, a bearing was starting to get a tad loose. So I scored a free one on a lifetime guarantee. No more volts dropping!

Bad news: it didn't help the "crappy" spot in accelerating.
Taking it for a long, long test drive tomorrow. Need to burn some expensive fuel through it and some of that injector cleaner.
Question Are dirty injectors much of a problem on these guys?

They've never been cleaned and I'm considering having a mechanic do an in-car cleaning.

There are not a lot of reported problems with injectors, but they can and do cause trouble. It seems to me that the guys who have gone to the trouble of having their injectors flow matched often report better fuel mileage (near 30mpg) than those of us who generally ignore the injectors. They are included in the list of items to check for hesitation in my '92 FSM:

TPS, O2 sensor, fuel pressure, contaminated fuel, canister purge, fuel injectors, fouled plugs, bad secondary wiring, ignition system ground, mem-cal, thermostat, generator voltage, air leaks between MAF and TB.

The FSM recommends an injector balance test be performed.

RedSled (my science project) is slowly recovering. Drove a number of miles yesterday/today. Can finally keep up on the interstate. Looking back, either the ICM harness rplcmt. or the questionable ground near the alternator were causing the code 42 (I hope). NO signs of it for days! Starts, idles & drives nice; but still has stumble at rev in Park or moderate throttle driving.
All 3 coils passed the resistance check yesterday.
Unplugging the MAF didn't help or might have made it worse.
Treated her to a new PCV, even though it is idling fine.
I have eliminated everything on the list above, except checking FP (at rev) and verifying clean injectors. Don't know if a fuel regulator could possibly limit volume & cause this. Will chk the latter on Friday & see what it does after this tank of go juice with the Techron in it.
Thanks for the feedback. Slowly, but surely.

UPDATE: 3/15/08-Was doing so good, I put it to the acid test and secured the PCM in proper place, instead of lying on floorboard. Wouldn't start. Pulled PCM out and did the unplug/replug and it fixed the no start. PCM is lying on the floor again.
Rechecked FP: 46 lb IGN ON; 38 lb run; 46 lb with rev in park
Injectors: For grins, ohmed out all injectors. All are equal at 12.3 ohms
Techron: Still have plenty of fuel to run through in hopes of cleaning
Need to check that "Canister Purge item above. Have checked vacuum and vapor lines.

Finally burnt off that tank of fuel and Techron. For grins, I re-did another tank w/Techron, since it seems to be doing better... and mileage is getting much better (20+). Will see if that helps more.
It still has the sputtering or missing at acceleration (driving), but not as bad in Park as it use to be. However, in OD or lockup, it will shudder/shake if I try to a accelerate moderately.

Q: I've tracked some threads that point to ignition with this latter symptom. So, if I have a few thousand miles on Champion plugs (that look GOOD w/o tail tell appearance) and equally new Beldin wires, and the coils passed the resistance checks .. whew ... any suggestions? (Good luck if you have to read this "classic.")
The guy with the PCM dangling on the floorboard.