sn95 PCM consistency and PIA factor. Why are the inconsistently a PAIN?

I know it's a 'cheaper' MAF, but what are your thoughts on the lightening MAF?

I know it's able to be cal'd but it is setup for the 42# injectors. I have alot of part throttle, low rpm bucking (1200-2300 Id guess but I havent driven it since last year). The cam is not terribly aggressive; and I can only think of one place for a vaccum leak. Could this be getting into the spark tables and such? Should I be looking for a new tuner?

My biggest peeve is the hanging idle. I don't like how it won't just drop if I am rolling. I was told this could be attribute to the speed sensor on the trans; but do you have any other thoughts?

I can agree to the fact of 'find a better tuner'....I guess sometimes they are harder to find than they lead to be. Might have to drag this thing down to LaSota at the worst. At least I'm in Ohio lol.
 
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Just some random thoughts :shrug:

First of all ... Peeps gripes here seem to be focused upon drivability

As said before ... This area of tuning is more difficult than WOT :crazy:

Issues such as these is where I have found datalogging be so
very helpful as you can look at the data at the conditions the
issues are occuring

You see idle issues in our cars often times :bang:

What I bet a lot of peeps are not aware of is :eek:

A cruise condition is just above idle as you have the throttle just
barely cracked open

therefore ... more often than not .............
peeps who have idle issues usually have cruise around town issues :(

Then you go for more pedal for more power .........

You now find yourself in a transition situation

Having said all that, You need to tune for that cruise (low load)
condition which will get spark/fuel as it needs to be

then

You might have to deal with the transition from cruise to accelerate
(low to mid load) which it might be what Keith is talking about :shrug:

Summing up with a WAG (wild azz guess :rlaugh:)

Sounds like Keith is too lean when going from low load to mid/high load
driving conditions

Also ... As for caled meters :D

When you peg the little stocker you really don't have a choice other
than move away from it

I run a ProM 80mm shorty caled for 30's and it has worked great for me :nice:
but
I do not try to run it in Cheat Mode :nono:

I uploaded an apporpiate maf transfer for it to the pcm ;)

Grady
 
It may be a combo of both the o2s being further down track and the maf "cheat" for larger inj. Most of the people who step further past 30lb inj seem to take a little more fine tuning. Like note above these things is were a 94/95 knowledgable tuner/time comes to play. If your using the PMS if I recall it leaves a little on the table in this area as far as control of items.
 
Just to clarify. I have longtubes, with the O2s way downstream. I have a MAF calibrated for 30lb/hr injectors. I do not have a wideband. The computer has never been dyno tuned. My car runs fine, with no real driveability issues. People have been setting up Mustangs like this for two decades. Your problem is elsewhere.

Kurt
 
Just to clarify. I have longtubes, with the O2s way downstream. I have a MAF calibrated for 30lb/hr injectors. I do not have a wideband. The computer has never been dyno tuned. My car runs fine, with no real driveability issues. People have been setting up Mustangs like this for two decades. Your problem is elsewhere.

Kurt

No 2 MAFs are the same and the calibrations can vary between 2 identical meters ALOT more than you think and I have explained this to you in previous post , we all know your car is one of the few ones that did not have a problem , but just so you know this is not the norm for 94-95 cars with calibrated meters over 24lbs injectors
 
it also depends on if there are bends in the tubing before the meter and how the meter is "clocked" in relation to the bends. here is my little story about that ...

i have 42# injectors a LMAF, and a TwEECer tuning system. and a while ago, i had a fender intake where there was a 90* bend before the maf. since the MAF transfer is well documented for the LMAF, i decided to keep that constant and tweak the injector flow to dial in the tune.

i was having a hell of a time tuning it. it was running so rich that i had to make the computer think that i had 49# injectors to lean it out. at that point, i decided there must be something else wrong, so i tried clocking the MAF 180* so that the element was on the side where the inner edge of the bend was. all of a sudden, it started running way lean.

why? the bend was causing the air to not be evenly distributed in the tube, and depending on the location of the element relative to where the air was concentrated, the maf would report different voltages for the same amount of air. and of course, the computer reads the MAF voltage, translates it into an amount of air it thinks is coming in, and makes the rest of its decisions based on that.

moral of the story? try not to have bends in the intake track before the MAF sensor.

now i have no bends at all before the MAF.
 
No 2 MAFs are the same and the calibrations can vary between 2 identical meters ALOT more than you think and I have explained this to you in previous post , we all know your car is one of the few ones that did not have a problem , but just so you know this is not the norm for 94-95 cars with calibrated meters over 24lbs injectors

I'm sorry dude, you're buying into a myth that's just not true. You can get a calibrated MAF to work in an SN just fine, regardless of what injector size you get it calibrated to. It's been done like this since the car came out in 94'. PMAS flowbench tunes their MAFs, so the calibrations are very accurate.

Kurt
 
I'm sorry dude, you're buying into a myth that's just not true. You can get a calibrated MAF to work in an SN just fine, regardless of what injector size you get it calibrated to. It's been done like this since the car came out in 94'. PMAS flowbench tunes their MAFs, so the calibrations are very accurate.

Kurt

Do you even know who I am , do you know how many cars I have had a wideband on with all brands of so called calibrated meters ? I tune cars everyday , meanwhile you drive your 1 car that just happens to have one of the few meters that was OK out of the box ......

I have about 3 people a week with 94-95 cars send me their SCT chips for reburns on cars that were supposedly dyno tuned that have issues and I have to go back over these other shops work to get the car to run or even idle .......

Id love to see actual wideband readings on your own car
 
Here you go

DynowithSpray.jpg


I've built plenty of Mustangs in my time, and I have never had a problem with a quality MAF.

Kurt
 
Sure the 94/95 PCM's are "better" but the A9x computer are "better" at their intended purposes. People, myself included, have always loved the Mustang because it was a true "bolt on" car. I really enjoyed all of my Fox's Because they were truely bolt on cars. I could throw half the Summit catalog at it, turn the key and go rip through some gears. I could even sit in a Wendy's drive through if I wanted!

Ford had different goals in mind when they built both the later model Foxes and the SN95 cars. They were strictly after power for value when they programmed the Fox Mustangs. They weren't really concerned with things like emissions and fuel economy or a smooth ride. The car was what it was and it was great.

Fast forward to 94, Ford had to keep the Mustang name alive while keeping the tree huggers and the feds happy. So they programmed the 94/95 computers to be more emission compliant while sacrificing "bolt on" compatibility. And since they KNEW the 5.0's were going the way of the dodo bird, they just didn't give a crap!

Mustangs were great because the average joe could spend money on a limited budget and go fast. Our cars were the beginning of the end of that. Tunes, chips, self tuning devices, widebands, etc... have taken the "Fun" factor out of the equation. Now you either have to pony up between 500 and 1000 bucks to get a descent tune IF you can find a competent tuner or you can buy everything you need to tune it yourself...but then you have to spend a year or two learning everything before you can begin enjoying your car again!!!

I for one would have plugged an A9L into my car long ago if they still made the plug n play PIH kit. I want to have fun with my car again and not constantly be worried about which part I bolt on will send my drivability into the trash!
 
The tuning thing really gets out of hand. I remember in the late 90s when Renegade didn't allow computer tuning, and people were driving around in 9 second cars on the street with a stock computer tune. There were plenty of 94 and 95 Mustangs in Renegade back then, and how did you think they got their cars to work with bigger injectors?

Kurt
 
to the OP, after 3 seperate tuning softwares and still having the same problems. It is pretty clear at that point there is something else wrong with your car.

i bought a tweecer Rt pretty recently and have been learning on my car in mostly stock form. looking at the tables and making very small changes. I dont have a wideband yet but that is in the works. I am also building a pretty stout 306 combo to go in the car pretty soon.

Tuning your car isnt rocket science. Just do some research to understand how the computer works. do lots of datalogging and pay attention to what your car is doing.
 
Guys, I have to agree with 2002 on this one. I originally (306) had a PMAS programmed for 24# injectors and it had to dyno tuned bc the MAF was so far off. The lightening meter ALSO had to be dyno tuned on my car. It did not run right without them tuning it.

As I said earlier, it all changed after I added long-tubes. My mechanic has checked for vac leaks, .. none. If you go back to what was changed.. that was it. I'll keep u posted, thanks for all the suggestions.
 
Here you go

I've built plenty of Mustangs in my time, and I have never had a problem with a quality MAF.

Kurt

Is that a nitrous run ? Lets see a motor pull ? and is that with your current setup ? how many passes on it ? Just so you know if that is a nitrous run , you are above 13 on the air/fuel from about 3450 to almost 4000 rpms , thats a little on the lean side FYI
 
Is that a nitrous run ? Lets see a motor pull ? and is that with your current setup ? how many passes on it ? Just so you know if that is a nitrous run , you are above 13 on the air/fuel from about 3450 to almost 4000 rpms , thats a little on the lean side FYI

Yes, that is on the nitrous. I wish I made that kind of power on motor. I've never made any passes with that much spray. The most I have ever sprayed at the track was 80, and it got a little sideways towards the end, so I let out. I have a motor dyno sheet somewhere, let me see if I can dig it out.

Kurt