ckyguy68

ive literally posted this question 5 times, but im thinking maybe a few of you havent seen it. my car will pop and stutter and sometimes stall after its been running for a while. it doesnt do this when the engine is cold. i am pretty good at diagnosing problems, but the symtoms just dont make sense. here they are.

only happens when car is warm.

i replaced the o2s, problem went away but came back after about a month.

i scaned the car. 'MAF input voltage low' ' Left and Right HEGOs detect system lean' 'low EGR voltage'

when this happenes, the car will pop and stutter under full throttle, and just feel EXTREMELY SLOW.

i unplugged my TPS when the problem started happening, and it just kept acting the same, but after like 5 minutes, it just stalled and wouldnt start back up.

it happened even more if i let the car idle for a little while.

it seems like i might be running rich, and fouling my o2s, but my plugs are WHITE.

the pop noise it makes sounds like someone hitting the bottom of a coffee can.

i can get a video clip if you want, but it is absolutely driving me NUTS. i cant stand it anymore, and im about ready to just carb it! PLEASE HELP ME!!!

Joel5.0

Sluggish, lack of power, pops and stutters, codes 66, 41 & 91 showing up (assume these are from a recent KOEO self-test scan....right?), symptoms worsen after warmup, spark plugs clean and white read lean condition (confirming codes 41& 91)......things to check/do:

1. Check fuel pressure w/gauge, and monitor it while engine is running with the symptoms, after engine warmup. This will eliminate a clogged fuel filter or fuel pump going 10-7 as the possible causes....if pressure stays over 35psi.

2. For code 66 and to verify MAF power, grounds and MAF output signal, perform the tests given on a previous post.....or...

the last output voltage check is recommended to be repeated by checking it at the ECM connector pin 50 (MAF SIG), to make sure a wiring problem is not a possible cause....use this wiring diagram.

3. Make sure there are no vacuum leaks that could be affecting A/F setting by the EEC-IV system.

4. After warming up the engine and have the symptoms show up....run a KOER self-test followed by a cylinder balance test...no need for a scanner, follow the DIY procedure described at http://www.themustang-net.com/eec.shtml using the CEL indicator, VOM or test light. These self-tests are also used as troubleshooting tools or confirmation runs of repairs, they need to be repeated.

5. In case you haven't yet, suggest to do the salt & pepper connectors fix.....JIC

Sorry man, but need to get the information that will help you id and correct the problem(s), otherwise, guessing will cause you keep on throwing parts($$) at it, hoping they will fix it. My

50mikey

Its running super lean! Do you have and adjustable FP regulator, if so check pressure. when was the last time the fuel filter was changed? Check into getting a new fuel pump possibly. I know that sound very well, and its not good on things! my problem was not enough fuel pressure

ckyguy68

ok ive decided to get an adjustable F/P regulator... where can i find one on a saturday? do they carry them at any common parts stores?

50mikey

well have you checked to see if thats your problem or not? cause if there is something wrong with the stock one, you could get one of those at an autoparts store (if in stock) today. whats the pressure at right now?

ckyguy68

i havent checked it, i dont have a f/p gauge. but im guessing that is it. im just sick of this problem and im willing to just go buy a new one. its so bad i cant even really drive my car. its like someone is flipping an on off switch to me car. it will go then stop then go, and then it will stall and stuff.

50mikey

I know what you mean. do you have a tire gauge? you can get a close number with that. I did it with tire gauge and FP guage and they read the same. youlld really need a gauge for the adjustable regulator cause its no where close to being right when you first get it.

ckyguy68

ok, i honestly dont even think i have a tire guage... at least like a dial kind. should i just go get a stock replacement? i mean, is it common for them to go bad. also, can i get a link to that idle video of your car?

Joel5.0

http://www.partsamerica.com/ProductL...re%20Regulator

Hope there's some $$ left when you find the real cause(s) of the problem.....Good Luck....

50mikey

if you must have it

dont show anyone else though!