Satan causes intermittent power loss/bucking?

(Warning: Long-winded reply ahead!)

Oh, I haven't logged all those 230+k miles on there, myself. That's how many miles are on the chassis, itself; the kid I bought the car from was clueless as to 75% of what all had been done to the vehicle before he got hold of it, and a lot of what I've been finding out of it has been through a lot of amatuer detective work ... one thing being that the car was originally born with an AOD and 2.73 granny gears. Whomever did the swap on this car did a VERY thorough job with the trim, pedals, and whatnot.

After discovering the reason why I have no CEL showing up is because SOMEONE YANKED THE WHOLE ASSEMBLY OUT FROM BEHIND THE FREAKIN' DASH (doh!), I finally pulled some codes today and came up with this weirdness:

- 67 = Clutch switch circuit failure OR Neutral Drive Switch (NDS) circuit failure, circuit open, or A/C input high
- 41 = HEGO (HO2S) sensor signal out of range / always lean
- 91 = HEGO (HO2S) sensor signal out of range / always lean OR Shift Solenoid 1 (ss1) circuit failure

Okay, the HEGO or HUGO or LEGO or whatever codes ... those I can try to remedy by swapping back in the stock airbox and seeing if maybe the cone filter setup is freaking out the MAF. If not that, then ... *sigh* ... it looks like I may be dumping $75 into a pair of fresh O2 sensors. The shift solenoid thing (I hate it when one code means, like, four different things in the book) is possibly attributable to the above mentioned AOD-to-T-5 swap, so no biggie, if that's the case - it's probably just looking for stuff that no longer exists in the drivetrain after the swap. Fuel injectors are all firing nicely, and the plugs don't look out of the norm.

But what gives with the clutch switch code? Far as I know, the clutch switch pretty much only serves as a safety lockout to keep you from starting the car while it's engaged in gear and/or to raise the idle just a tad when you depress the clutch (at least that's what it does on my FrankenStang, anyway).

Distributor shaft was nice and tight when I was fiddling with the cap/rotor the other day. I think the premature wear in this case might be due to a combination of it being a cheap-azz AutoZone part (sadly, I'm not all that proud of some of the crap we sell) and/or the recent Arizona Monsoon weather we've had, what with all the high humidity and such lately. Accel cap's getting slapped on first thing tomorrow.

About the MAF unplugging test ... I recall seeing a post not too long ago (might've been on the Corral) saying it was a major no-no to go unplugging that while it's running. I'll give the wires another cleaning when I swap the stock airbox back in tomorrow to see if that affects the lean condition.

The lean-running codes pretty much rule out a lack of spark, so it looks like it's a fuel delivery issue. The pump's not making any funky noises and it's surely not original, as the tank and surrounding hardware has all the telltale signs of having been dropped and fiddled with at some point, though I've no idea if it's an OEM replacement or an upgraded pump they decided to plug in (although it would've been nice if they'd bothered to reconnect the fuel level sending unit ). I'd sooner swap distributors and re-time the motor before I go dropping the tank and prodding around that thing anytime soon, as I've already done a full tank/strap/pump/filter/sending unit replacement on my previous '89 notchback ... NOT FUN. But something to keep in mind, nevertheless, if all else fails.

I feel like I'm FINALLY seeing a bit of light at the end of the tunnel ("Ah see the light! Ah see the light! Hallelujah, bruthas and sis-tahs! Yes-ah!"). Y'all have been a tremendous help thus far with the suggestions! The King of Lies may yet be evicted from my engine bay...

Ahhh ... I see. I usually leave my car in 1st with the E-brake on when it's parked, so that might explain the 1st Gear shift solenoid code. That was the only one of the codes that wasn't in the constant memory, so I guess that's that.

HOWEVER ...

... swapping out the dist cap/rotor for an Accel unit, swapping back in the stock airbox w/paper filter, cleaning the wires, and resetting the computer still didn't change the surging. So, my list of suspects related to lean conditions at this point are the fuel pressure regulator and/or the O2 sensors ... unless, worst of all, my fuel pump is going to crap.

I dunno. I think the world in general just hates me right now, and it's channeling its spite and rage through my Mustang as a means of punishing me for ... uh ... whatever it was I did/didn't do.

10-pins = "Salt and Pepper Shakers," mounted near the firewall, right by the fuel pressure regulator. That was one of the first things I fiddled with when I first obtained the car a couple of months ago - sprayed the crap out of it with contact cleaner, spread out all the little connectors with a pin to ensure better contact, and smeared a fresh coating of dielectric grease in there. I could always re-clean them, but I'm not putting much faith in the hope that it'll do the trick in this case.

The lean condition thing *almost* makes sense so far, except as far as the fact that I have absolutely ZERO pinging. I've read elsewhere on here that if your O2's aren't working correctly, it'll read that you're running lean and it'll cause the system to dump a ton more fuel, which would explain the backfiring and popping that I get during those times of Satanic possession (the car, that is, not me ).

A non-adjustable FPR is less than $20, so I might give that a shot before I go and spend the bigger bucks on new O2 sensors - with about 200k miles on it, I'm sure it wouldn't hurt to give it a change, anyway. Dunno if it's worth it to blow another $100 to invest in an adjustable unit and a fuel rail gauge, as I don't have any really wild mods planned in the future. I just want the friggin' thing to run properly so I can get back n' forth to work and get a couple good runs in at the track next spring before I even dream about doing anything more!

If the HEGO's are at fault and causing the actual rich condition (because it's reading lean), and because it's intermittent, would that explain why my plugs aren't fouled, ashey, or oddly-colored? ... because it runs just dandy when it's not being toyed with by the Dark Prince from time to time, so the excess gets burned off, or it isn't enough to accumulate?

FWIW, switching to the paper filter and stock airbox seemed to make my idle a tad smoother, but the surge/power loss is still as hit n' miss as ever at cruise/acceleration...

True, true. I'll give the O2 disconnect trick a shot tomorrow morning. Heck, at this point, if hanging an officially blessed crucifix from my mirror, driving backwards for 50 miles, and singing "Joy to the World" at the top of my lungs would do the trick, I'd go for it.

Just filled up last night for $2.55 a gallon (87 octane). I'm averaging 14.6 mpg now. Ugh. Normally, crappy mileage would be a sure indicator of the O2's, but with the short drive to work that I now have (less than 5 miles), I can't be sure if it's simply due to the fact that the car's barely getting up to operating temperature before I shut it off.

87 octane = all I can afford!

Seriously. Just got paid two days ago, and I'm already pinching pennies. That's why this whole Satanic issue is just killing me. Mayhaps I should instead look into a way to convert my ride into the world's first Hybrid Mustang ... something that'll get, like, 75 mpg and still do 14's in the 1/4 mile...

Car seems to have healed itself for the time being. Haven't changed a thing since the last time it got fussy.

Any other thoughts on the lean condition? Anyone?

Thanks, but I already replaced it. Didn't seem to affect the surge/power loss issue at all. The fact that the car hasn't been doing this for the past couple days means that either it knows I'm out of money for the next two weeks, or the ECM has re-trained itself to accept the stock airbox/paper filter and isn't giving it a lean mix reading, anymore. I'll see how it rolls the rest of this week and post an update. I'm reeeeeeally not wanting to mess with the O2's and/or the fuel pressure regulator, but if that's all that is left ... wellllllll...