Satan causes intermittent power loss/bucking?

Discussion in 'Fox 5.0 Mustang Tech' started by Darkwriter77, Aug 15, 2005.

  1. I'll poke around for it in Friday (next day off) and see if I can locate/clean it. I've already done the braided stainless ground that runs from the driver's side cylinder head to the firewall. Is this other one on the passenger side, kinda behind the fuel pressure regulator? Don't recall seeing another one there when I had everything pulled off to do the injectors last time, but I wasn't really dealing with ground wires back then, either...

    - Coolant Temp Sensor?
    - MAF?
    - TPS?
    - Overlooked ground wire(s)?
  2. The braided stainless steel ground strap and the injector harness ground mentioned in my first post, fasten to the driver's side cylinder head with the same bolt. I found it because I was completely removing the injector harness from the engine compartment. Mine was very dirty, almost green. See if you can find it, clean it very well and tell us how it turns out.

  3. Try hitting the maf while its running, ive heard of people doing this and it would make it run good or bad and told them that was the culprit. I would try replacing the IAT Intake Air Temp, this also has to do with the air/fuel ratio. This is the next thing on my list since we got the same problem :rolleyes: and mine looked black when i had it out last.

    BTW I think the ground you are talking about is the O2 sensor heater ground. Theres only 2 back there and the other is the metal braid ground strap which attaches to the back of the head from the body, although mine two are grounded to the rear intake manifold bolt :rolleyes:. The injectors dont have a external ground, its inside the computer and that is how the computer energizes the injector...Grounds out that injector=completing the circuit=turning on the injector Ill be waiting to see if the new reman. dizzy will help out :nice:
  4. Well, the reman dist didn't cure the symptoms, it only got me back on the road again ... which I certainly can't complain about, having been sidelined for a week.

    The ground for the ECU is clean, as well as the braided stainless ground off the cylinder head, the one near the starter solenoid, the ones for the battery, and also the two up front along the radiator brace.

    Verified that every fusible link in existence under the hood is in good working order yesterday, too.

    Scratching grounds off the list and adding the IAT on there. Haven't touched that one, yet. Might sound silly, but am I going to need to wrap the threads on it with Teflon, being that it's a brass fitting going into an aluminum intake?
  5. The EFI power ground is attached to the body with what looks like an inline fuse holder. It is located next to the starter solenoid. It that the ground you checked?

    The ground inside the car next to the computer is the TFI wiring shield & computer case ground.
  6. When I reinstalled mine I did so there couldnt be any air leaks.
  7. 'Kay. Well, both grounds - the one near the solenoid and the other right under the ECM - have already been cleaned and gooped with a little dielectric. Figured if I'm gonna be doing all this, anyway, I may as well go the full mile, so I loaded up on a new TPS, IAT, and coolant temp sensor. Plugging them in tomorrow morning. If it works, huzzah, and if not, I'll keep the old ones for spares ... along with the twenty or so other sensors and whatnots I have spares of in a little box in the back of my car. Emergency stash. :)
  8. Replaced the TPS and IAT this morning. The old IAT did need replacing for sure, as it was so black and caked with nasty tar-like goop that it couldn't have been getting a good reading of anything, anyhow.

    Nevertheless ... no change. Same symptoms. I still have yet to put in the coolant temp sensor I have laying around, as well as the new fuel pump (which I'm now just planning to do as an upgrade, anyway ... 155 lph Edelbrock should suffice for future mods). Again, fuel pressures when I've measured them have been good, but I can never seem to catch it when it's having one of its little hissy-fit moments to see if the pressure's dropping then, or if it's some other gig causing the problem. Car still alternates between feeling utterly gutless and then to having plenty of "bowlssss" (as they pronounce it on The Sopranos). ;)

    So, new list of the moment:

    - MAF
    - Fuel Pump
    - Coolant Temp Sensor
  9. Im not sure on how ur problem acts but im pretty sure its an ignition problem. Mine bucks as if spark is cutting out or something. A fuel pump couldnt do it that quickly though. Since you changed the dizzy,tfi module, map/bap sensor, iat,tps,cleaned grounds,new computer? im not sure if u got ur new one in or not. I dont no what else it could be :shrug: Have you ran a KOER test (same as regular code reading test except with engine running basically) it tests all the sensors while its running and can also do a cylinder balance test (but you dont need to do this)? I ran a KOER test and I got a code 18 and it said SPOUT circuit open or Spark Angle Word (SAW) circuit failure and also a code 22 for map/bap sensor.. And I also got the code 18 in Continous memory and that is IDM Circuit failure/SPOUT Circuit grounded. Ive checked the entire Spout circuit with an ohmeter and it was fine, no opens, shorts, high resistance...This def. has to do with my problem, Spout has to do with the ignition timing and the bucking is caused by the timing deal. This is causing my timing to show it is 65 degrees advanced!! and this is with the Spout Connector In Or Out!!! and theres no way it can run with this much timing obviously. This just started after dropping my new motor in and I reused all my old sensors, distributor, computer, everything, Just a new longblock really, so i was lost on what could be wrong since everything was fine with the old motor. I think its a wiring problem but can't find anything wrong...Im not saying this is your problem but just a suggestion. Where is your timing? Is it working properly? Try checking ur KOER codes and see what u get.
  10. My code reader won't allow me to pull any KOER codes until I have an "all clear" code available for the KOEO reading - if there are any trouble codes stored in the memory, it won't take readings for an engine-running test. Haven't pulled codes yet after replacing sensors yesterday, but that'll be next on my list of to-do's.

    Timing's at 12*. The ENTIRE ignition system is new: cap, rotor, plugs, wires, distributor (reman unit, see prior posts for that headache), coil, fusible links, and ECU relay. Just about the only sensor I haven't yet replaced is the MAF; already done the TPS, IAT, EGR position, and O2 sensors. Replaced every inch of vacuum hose in existence. Replaced EGR valve, IAC valve, hosed out the intake with Seafoam and (Deep Creep) intake spray, changed out every fluid and filter in the car (yes, even the PCV valve and screen), replaced the entire exhaust system (except the headers, themselves). I've installed mechanical gauges, and all readings of temp, volt, and oil are perfectly good.

    So ... unless it's the MAF or fuel pump, by chance, then the only thing left is ... well ... Satan. I guess. Or something. And stuff. Um, yeah.
  11. Darkwriter any update on your problem? I just changed my lifters and after that my car has a bad misifre, I got it a little better but still trying to figure out what is wrong, im thinking maybe i cracked some porcelain on a plug or somethig when i put the plugs back in, my bucking problem is gone though haa it just runs as if I pulled a plug wire off a spark plug :nonono: BTW My pump went and I put in a 255 and that didnt help.
  12. GOOD NEWS!! (finally!)

    Although I still haven't had time to put in the new pump n' stuff, I decided to take advantage of our extra holiday employee discount where I work, and thus managed to pick up a new MAF (housing, sensor, screen, and all) for a mere $58. Plopped it in there right away, and ... *GASP!* ... I haven't had a hiccup or loss of power since! Been three days now, still chewing my nails and waiting for it to come back ... but I'm really, REALLY sure that this was the final silver bullet/holy water/blessed crucifix/garlic/rosary/Bible/magic-relic-of-choice to finally exorcise the demonic presence from within the confines of my engine bay!

    First off, there's the obvious mileage issue: 250k+ miles on what looked to be the original MAF? Hmmm. Secondly, my old MAF was missing the screen on the front of the housing. And lastly, it was the last of two remaining parts in the entire frickin' engine bay that hasn't been changed out, tested, adjusted, cleaned, or otherwise ruled out (the other being the EGR vacuum solenoid on the passenger-side fender).

    Car pulls like a mofo, purrs like a happy kitten at idle, and I'm hoping my mileage will get a bit of a boost, as well. Santa brought me the bestest present of all, and fifteen days early, at that! ... 'cause, y'know, he felt sorry for me, or something. :D

    Also used my discount (and my 15 hours of overtime pay from last week) to invest in one other mandatory accessory: the all-important, standard-issue Autometer Monster Shift-Lite tach. Oh yes. I am a happy, happy camper, now. Very, very, very happy. 'Tis peanut butter jelly time, indeed. :banana:

    Once again, many, MANY thanks to all of you who've offered suggestions and info to me throughout this crusade. My goal in this was that I could resolve the whole problem without having to submit to my temptation to just haul the beast over to a Ford stealership and have them rape me for a few hundred bucks, only to find out it was something I could've changed out in five minutes, all along. I love you guys. Seriously. You rock. :SNSign: :hail2:

    To recap, in the hopes that I may somehow help others by saving them from blowing hundreds of hard-earned dollars, here are the things that it turned out NOT to be (although many of them, in my case, needed changing due to general old age):
    - Distributor ($75, OEM reman ... which failed and left me stranded)
    - Plug Wires ($40, Accel Spiral)
    - Plugs ($16, Motorcraft)
    - Cap/Rotor ($20, Accel)
    - Ignition Coil ($35, MSD)
    - IAC ($35)
    - TPS ($25)
    - EGR Valve ($75? Can't remember)
    - EGR Valve Position Sensor ($40?)
    - ECU Relay ($10)
    - Full Seafoam and Deep Creep Treatment ($10)
    - IAT ($20)
    - Extra Negative Battery Cable ($10)
    - BAP Sensor ($40?)
    - Timing Light to check/set timing ($40)
    - TFI Module ($40)
    - Fuel Pressure Gauge to rule out fuel pump ($30)
    - Fuel Pump w/Strainer ($110, Edelbrock 155 lph)

    ...and finally...

    - MAF ($60, OEM reman)

    est. Total Dollars Wasted on "Operation Satanic Possession": $731
    Number of Replies in This Thread (so far): 110
    Hours, Beers, and Brain Cells Wasted Throughout Operation: Countless
    Labor Hours Saved/Wasted by Not Paying a Pro Mechanic to Diagnose/Change Out All of the Above: (I dare not even TRY to put a number here)
    Moral of Story: I am an idiot with more credit card debt than common sense. :doh:
  13. Awesome Glad to hear you got your evil little satan out of ur engine bay :nice: So now you have no bucking right? Where did u get the new maf, the Ford dealer or a normal parts store? I can get like a half price discount from Ford :D I might just pick one up Was it the whole thing?
    The aluminum base and the electronics, did u keep that metal screen in or just take it out, I know most people just take them out.
  14. I was going to say its your EEC or the EEC Relay i had the same symptoms at first and then they slowly progressed into not starting when hot and not being able to get the codes and it turned out to be my computer. Glad you fixed it.
  15. Glad to see you got it running.:nice:

    See if you would have just paid a little more attention to Post # 72 you might have slayed this demon earlier.:rlaugh:
  16. The stock MAF screen is a fooler. Many people remove it thinking it restricts airflow. In reality, it helps smooth and direct the airflow. Glad to hear you got it fixed. Patience is a virtue.
  17. Yeah, it was the whole unit - sensor, aluminum housing, screen, even the little red rubber booty for the plug - and the normal cost was $76 through my store (Autozone) plus a $60 core ... but, since I was able to just swap it out right there in the lot, and I had that extra discount this weekend (which coincided with everyone getting paid on Friday ... hmmmm...), it came out to about $58 total with tax.

    No bucking, no surging, no power loss ... no Satan! :) I was having a sneaking suspicion that the missing MAF screen might've been part of the problem, since it seems that anything I ever did to modify anything ahead of the MAF would make it do some odd things. (Ex: Putting a cheap-o cone filter setup on there made the car really jerky at parking lot speeds, but going back to the stock FRAM and airbox setup smoothed it right out.) Unless there's really THAT much of a gain to be had from a K&N panel filter, I suppose I'll just stick with the stock junk with only the silencer removed. Don't wanna anger the MAF gods any more. :)
  18. Ok cool first ill try putting the stock screen back in since i got it without one and if that does nothing ill get a new maf. Now i got to find where my misfiring demon is hiding lol
  19. glad to hear it worked out for ya darkwriter :nice:

    now you can rejoice, because you've got a brand new car with no evil presence hehe

    stangnet 4 lyfe :stupid:
  20. hey--I have a 1990 gt and am having the same problems. I changed out the fuel pump tp 155lph and holley adj. fuel regulator. I have all new ignition including dist. and still can't find the problem. my car will run fine and then start missing and then fine again. good luck with the fuel--didnt help my poor car though.