scottyd2506

How do you tell if you have a bad MAF?

My car keeps running crappy.. pulls hard on the upper rpms.. bogs down low when you floor it...
I read where one guy cleaned his maf and gained 60 rwhp. as he had a K&N filter (oil).. I have same filter.. so I took off my MAF, sprayed if with MAF cleaner.. and low and behold it ran worse... now it's stuttering, missing.. idles rougher..

I suspect maybe this MAF is faulty, and the reason the previous owner lost 20 rwhp and 20 rwtq (395/352 to 371/333 from mustang dyno to dynojet too. (went from true duals to Y pipe).

When he had it tuned the 2nd time -- is it possible that it was tuned with a dirty or faulty maf... and when I cleaned it, it set everything out of wack?

with MAF pluged in like normal, I can stomp it, and it bogs, tirs barely break traction.. and it pulls in upper rpm's, when it hits 2nd it bogs a slight bit of a sec but when the RPM's go up it pulls hard..

When I go out and unplug the MAF, and I stomp it... the engine goes from like 900-1000 rpm's to 5000-6000 instantly.. and the back tires are up in smoke.. like I gained 200 ft lbs of torque.. running in SD mode.
of course running maf unplugged it idles lower, and I can tell AF mixture is off..
I don't have any tuner program.. plan to have it tuned again once I get bad parts fixed.... ANY ideas???

thks

69LT1Bird

iTrader: (1)

go get a MAF from a junk yard or a buddies car and swap it out.

scottyd2506

That is what I am asking before I plunk down $$ for another unit, could something else be wrong.. or what I am saying is, when I unplug the MAF... and it is in SD mode, does SD mode bypass other censers that could be faulty?

thanks

CalEditor

iTrader: (1)

I can feel it!!!!!!

I dive the same type of cars every day. I get in one with an incorrect MAF reading and I know it within a few blocks.
What? How?
They feel retarded and the trans shift are long. Long?
Yes the Shift speeds are very slow for the amount of TPS. Remember the car feels like the timing is retarded.

I just sent a picture to a friend of a MAF on a car I test drove and knew the MAF reading was incorrect. Let me upload it and get back to this.

CalEditor

iTrader: (1)

I probably knocked some of it off, but this is about all it takes.


I have seen spiders mess up a MAF by building a web in the MAF

scottyd2506

close,

I actualy took the MAf alu ends off to clean the MAF wires on both sides, bought a $10 of MAF cleaner to be safe..... when I cleaned it, the car ran worse.. (so much for safe)

power wiSe.. it always is strong on the upper rpms, but not down low.. now with MAF unplugged, I have killer torque.

I'm getting anothr MAF soon.

keep you posted

scottyd2506

uhdate!!!

Bought me a junkyard MAF (have another one comming through mail in a week).. cleaned it with maf cleaner... installed on car... drove it around.. and it still runs just like the old cleaned MAF.

here is the takedown

(1) old Dirty MAF
Smoother idle, surges some, no missing, easy to drive.. but bogs off line and when it shifts into gears at WOT.. pulls Hard to 6500 rpms

(2) old MAF cleaned
rougher idle, suges bad at low rpms, misses at mid range rpms, bogs off line and at shifts, lack of WOT power, esp upper rpms.

(3) unplug maf, still surges at low rpms..but has awesome off line power, no bogging when ***** either, WOT upper RPMs power is ok, but not as good as old DIRTY MAF

(4) junkyard replacment MAF (from 98 truck), suns same as #(2), old cleaned MAF



I don't get it..
All I can think of (this gets expensive) is that the car was tuned with the dirty maf, and now a clean one throws off the dirty maf' tunes afm's and timing...

Any tuners out there can shine in for me please.??
Can't figure it out..