Satan causes intermittent power loss/bucking?

In general, about the only thing that can cause surging or power loss is some variation or loss of spark or fuel delivery, over simplified I know. Deciding which one is the cause is the 64 thousand dollar question. I depend a lot on sounds and conditions when diagnosing my own car (maybe a sound clip would help ?). Are you still on your original fuel pump at 230K miles ? I sure hope not ! :) It's sounding like a fuel delivery problem to me, which should be more evident when it's hot, but still. Is your fuel pump unusually loud or whiney ? It would be nice if you could see what your fuel pressure is doing while your are actually driving, but I would test it at the fuel rail with a tester gauge if nothing else. Even if the fuel pump is good, the fuel pressure regulator could be acting up also. So if you plan to keep the car a new fuel pump, adjustable fuel pressure regulator and gauge on the fuel rail would be some nice additions.
 
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check for side to side play in the dist. shaft while you have the cap off. If the dist. is worn out, the rotor will "wobble" causing it to eat up caps quickly. I have even seen a cap dancing around at idle.

Next time it starts its bucking, unplug the MAF sensor and see if the problem goes away. This will throw it into open loop I know a guy who was having a problem similar to yours. He noticed it happened on rainy or high humidity days. He would unplug the MAF and it would go away. I ohmed out the wiring and the MAF circuit in the puter and it tested good. Put the puter back in a ran it till it started to run bad again. Pulled out the puter and tested the MAF circuit again and it was open. A new puter fixed his. These things are tough to diagnose because you can only test things when the problem is actually happening. If it runs good at the time everything will test fine.

I highly recommend the Charles Probst book on ford EEC IV systems and a good high impeadence multi-meter.
 
he did complete service on injectors....

im beginning to suspect your ecu as well... theres so much to go wrong in there

complete list of surging causes... sorry thatd be longer than the chinese alphabet

EGR position sensor might not cause that, but its worth a shot

dont get discouraged and give up, after all the money youve put into it already....

another ?.... howd u put 230k on a rebuilt engine haha... thats more than most factory fox engines... u must drive cross country every weekend or something


anyway darkwriter... i hope you eventually find your problem

if you havent replaced it yet, pick up a $15 voltage regulator to possibly perk up your electrical systems a bit...they can go bad and frig some shid up
 
(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 :nonono: ). 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. :notnice: 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...
 
dunno wut that code 67 means, but i know one of the sensors on the t5 is a neutral drive switch, and if i recall, the computer wont spit out codes unless ur tranny is in neutral...?
 
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. :bang:
 
They are the two connectors that connect the PCM to the the injectors, sensors and actuators that control most engine functions. One is white and one is black, they are about the size of salt and pepper shakers. There was a service note to add a couple of interconnectors with ob-round connections to eliminate intermittents.

Good Luck, Don
 
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 :p ).

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...
 
Better yet... just DISCONNECT the 02 sensors and see if the car stops surging first. A sensor that is just flat inoperative should not cause the symptoms you've described however, one that's working intermittently might. You'll be running rich (of course) for this test but if the surging goes away then at least you'll know you're not buying sensors for nothing.
 
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... :nice:
 
Darkwriter77 said:
Nope, not SD-equipped ... otherwise I wouldn't have had any MAF wires to clean. :D

Fluid loss, sure, but nothing major. Need to replace the O-ring around the VSS unit that plugs into the side of the tranny, as that's dripping just enough DexIII onto my hot cats to make a horrid stink. Not dripping/burning any motor oil, not losing any coolant.

I suppose the MAP sensor is about the only thing I haven't toyed with or replaced yet, but they're a bit pricey for me to just go pick one up and HOPE it does the trick. Ye Olde Chilton manual isn't much help for diagnosing these sorts of things.

Oddly enough, while playing the last track of the Pulp Fiction soundtrack whilest driving, the car acted up again. Its ill reaction to the recitation of scripture seems to verify my suspicion that Satan is at fault... :scratch:
i have a map sensor if u want it
 
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... :(
 
As i've stated i've got a pair of O2 sensors that i will send you via no cost to you if you pm me with the address you want them delivered. I had an idle surge problem i thought was related to the sensors so i replaced them and that wasnt the problem but i kept the new sensors so just let me know. Good Luck!