Problems With New Pro M 80mm

Discussion in 'Fox 5.0 Mustang Tech' started by skiwesser11, Aug 13, 2014.

  1. Ok, have 306, AFR 165's (58cc), edel rpm2 intake,
    Ed Curtis cam -(.588"219/[email protected])
    pro M 80mm
    24# inj.
    Long tubes, ect..

    Problem is the car absolutely will not run with the pro m, I had already sold the 73mm C&L trying to recoup some of the $ I was spending so I only have a stock meter to swap, but it runs like it should with a meter for 19's with stock one swapped with pro m no other changes. I can drive it around fine, again, I can barely keep it running with the 80 much less drive. No throttle response at all, it's just chucking and hunting, will not rev or respond to throttle input.

    I'm waiting to hear back from pro m but I don't think there's anything wrong with the meter (I taped off 2/3 of the filter and clocked it 90*) and it runs better, I taped it off because I think there's too much air (or not enough??) and ECU isn't able to read accurately. And from what I'm seeing that seems to be what's happening.
    It's driving me crazy! I know the pro m is a good piece, any ideas??
  2. Are you running a air filter under the hood/ram air? or are you running a true cold air kit/fender well? Because if you are running an open air filter under the hood with the heat and the air from the fan will have problems matter what mass air meter you run.
  3. Right now I'm running it underhood with filter on end like it comes from pro m. I was told on phone by a rep from them that most ppl run it that way, or relocate into fender (which is my future plan) but cannot put elbow with filter in fender before meter as I had the C&L. I was told by pro m rep it would not meter well in that configuration. So for now it's underhood but heat isn't the problem, it won't run long enough to get hot with pro m.

    Stock meter is also being run with filter right at meter, underhood, no problems.
  4. The problem is not only heat, but turbulent airflow caused by the fan and under car airflow.

    OEM Ford and Pro-M meters have totally different designs. The stock 55 MM Ford MAF has a screen in front of it to straighten out the airflow. The Pro-M doesn't have this feature and is designed to pull air from a location like the stock air box where there is minimum airflow turbulence.
  5. I would also dare to exclude turbulence as a major influence of the pro m not seeming to function properly as the stock meter I am using has no screen or other means of eliminating turbulence, unless there is a principal at work that I'm not aware of??
  6. Pro-m should work with you on it. They recently helped me trouble shoot one of their mafs, that I bought used. They do build then differently depending in what type of intake you run, but I would wait to hear back from the rep.

  7. Glad to hear that, I'm hoping so as I bought it new directly from them in April. Although I just got done with motor, I don't think there's any kind of warranty on it anyway.

    I really starting believe there's a problem with it, but it appears the engine doesn't like the bigger housing, that just shouldn't be so we shall see.
    Thanks everyone.
  8. is the MAF dirty? Try to clean it using some CNC MAF cleaner and light compressed air
  9. It needs to be moved out of the engine bay.
  10. We did, also again it's brand new, never used. But we still made sure nothing was obstructing and blew it out well.

    Agreed, but still it should run!! I drive it all day with stock maf. Looking for someone local with 24's to try on their car. My friend with a C&L I'm gonna try is out of town for a few days.

    I'm hoping Pro M will want to check it and they will find a problem I do believe.
    Thank you guys.
  11. No dump of the codes means that there could be other issues that you are unaware of. If you indeed have a malfunctioning MAF, it may very well set code 66 for a MAF problem.

    Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

    Dumping the computer diagnostic codes on 86-95 Mustangs

    Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

    Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

    Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

    Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

    Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
    Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.



    If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.


    The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

    89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.


    The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

    WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

    What to expect:
    You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and driveablity problems

    Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

    Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, and clutch (if present) is pressed to the floor, and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

    Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

    Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
    See AutoZone Part Number: 25886 , $10

    Alternate methods:
    For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

    Or for a nicer scanner see Equus - Digital Ford Code Reader (3145It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
  12. Try emailing Sean Trotter, he is the owner of Pro M Racing and has answered questions about his products to me in the past. He may have a solution to your problem. [email protected]
  13. The only KOEO codes are emission related and code 95 from the mass air conversion . It will not run well enough to pull KOER codes with the pro m installed.

    I am waiting to hear from him/them.

    Thank you
  14. It was calibrated for 42's instead of 24's.
    They made it right, runs fine now.
    89stang1 and RangerJoe like this.
  15. Glad to see it all worked out.

    Also glad you updated. I can't count the amount of guys that post up and issue on here that leaves everyone scratching their heads, somehow get's it fixed and then disappears from existence without an update, leaving us all wondering what happened.
    A5literMan likes this.
  16. Almost as many guys do that as the ones that come here looking to build 1000rwhp cars or stock shortblock 302's running 7500rpm.
  17. I have received a lot of quality info on here as of late from several people. 2000xp8 ,jrichker ,Rangerjoe , madspeed, noobz347, mikestang63
    Just to thank a few, I really appreciate the time fellas!!
  18. Ok, so how much power am I making exactly??? lol......prob south of 1000

    306, AFR 165's (58cc comb chambers & upgraded springs),
    Edelbrock rpm2 intake,
    Ed Curtis cam -(.588"219/[email protected])don't tell anyone else
    65mm TB
    pro M 80mm
    24# injectors
    U drive pullies on crank and alt.
    1 5/8"Long tubes, no cats, flow master 3 chamber mufflers full tailpipes.

    I think that's most of engine mods that matter?
  19. pro-m and pmas are the only way to go with maf and prolly 330rwhp 340rwt (dynojet) with that healthy cam! you left out compression i gave you close to 11.1 thats why i was so gracious with numbers
    #19 89stang1, Aug 29, 2014
    Last edited: Aug 29, 2014
  20. Not exactly sure on compression. Forged aluminum pistons I'll have to find part no. I think I'm closer to 10:1 than 11:1 but I'm not sure.