Fuel help 42's to small?

[Forcedpower]

Hawk think you missed one of my post. I turned fuel up to 50 and took the car down the road under full boost the fp went to 58-59 hard to look at the gauge when doing 100. I only run 9-10# of boost so that sounds right to me. Had this mass air for a couple years never had this problem with my old set up. Just b/c I'm moving more air now?

[TheHawk05]

Musta missed that one...sorry. Well if that's the case it's sounds more and more like the MAF voltage is maxing out now due to the increase in Airflow which could have been quite substantial depending on the combo your MAF was being used with before.

[Forcedpower]

So when the meter gets pegged what happens? The computer go back to default tables or something?

[regattacoupe]

Well when that happens it cannot increase the pulse width any further.

[frdfandc]

Basically what Brent is saying is that the Meter is stuck at full tilt boogey and the computer is seeing that the Meter is registering 100% and not allowing the injectors to increase its duty cylce (inject more fuel).

[Forcedpower]

I hooked a volt meter up to my meter I used pins C and D which C is also a ground. Anyway at 5000 I'm over 5v and at 5500 I'm at 5.35v. Looking at the pro-m site they say most recals are b/c the meter is dirty will dirt really make it that far off? Thanks for the help guys.

[itlkick]

I hooked a volt meter up to my meter I used pins C and D which C is also a ground. Anyway at 5000 I'm over 5v and at 5500 I'm at 5.35v. Looking at the pro-m site they say most recals are b/c the meter is dirty will dirt really make it that far off? Thanks for the help guys.

5.35 volts is in all practical cases impossible. Either your meter was bad or you were really freakin over the limit!

A dirty MAF will make the voltage go higher.

The way a MAF works is by trying to heat a wire in the air stream and maintain a constant temperature. The more air that flows past it the more voltage it takes to keep the wire heated. 5 volts is all the heating circuit has.

A dirty wire will either insulate the wire (make voltage lower) or make it harder to heat the wire (make voltage higher). It depends on what is on the wire. If it is an insulator it will lower voltage. If the contamination is a conductor (dirty oil or metal dust) it will raise the voltage.

[fanglemeister]

Ya, eec supplies & runs on 5v reference voltage, not sure how or why it ran up any higher than that. In any case the MAF transfer function in the '93 eecIV only goes up to 4.78v, Ford left alot of fuel flow on the table not programming it to read all the way up to 4.99v, probably 60-80 hp worth [edit: on a 42# meter]. As it stands without eec modification it is shooting the same amount of fuel whether reading at 4.78v or at 5.3v -

[Forcedpower]

So what you are saying is even if I get the meter recalibrated it won't make much diff b/c my computer only goes to 4.78v? So most likely I will still run lean on the top end unless I get my mass voltage raised to 5v?

[fanglemeister]

For whatever reason it seems you are running out of MAF headroom. Based on the dyno chart a/f curve it looks like it goes richer as flow increases -- is this a blower-calibrated MAF meter? The fact that a 42# meter is hitting 5v at 450hp seems to indicate either a malfunctioning sensor, dirty sensor, or simply that Pro-M has it set to run too rich on the top end (blower cal). Did you get a chance to clean the sensor element real well?

Getting the eec retuned to raise the MAF max voltage from 4.78v to 4.99V should give you *at least* another 40hp worth of metering out of your setup, in your case raise it from 450hp to 490hp or so.

The other thing is bsfc, your setup should be good up to 525hp @ .55 bsfc but only 490-500 running at .6 bsfc -- and based on your dyno chart I'd say you are right around .59 bsfc.

An alternative method is to have Pro-M recal your MAF to work with slightly bigger injectors, say 46# or 50# injectors, and then make your 42s emulate 46s or 50s by raising the fuel pressure to 52psi or 60 psi. Recalibrating the meter costs $$ but this is certainly going to be a cheaper solution than going with bigger injectors and an all-new meter.

If you decide to get the eec retuned, the tuner will want the flow sheet from Pro-M to put the exact numbers in the program.

[Forcedpower]

The maf is for a sc. At 3500 thats when my fuel pump kicks in. I have the pump controller from Aeromotive.

I cleaned it real good last night, didn't look dirty to me at all. Didn't get a chance to try it out yet, but I don't think it fixed it.

Guess I'll have to send it back and have them recalibrate it. Then I'll have to look into some kind of tuneing tool don't want to give up maybe 40hp.

[nstycpe93]

i have a 331 stroker also with vortech t trim, rpm heads, aeromotive fuel system complete with 42 lbers and 75mm maf.
it went 558 to rear with 512 torque. this was with a typhoon intake,
i have since went to a spyder intake, with 50lbers. 80mm maf.pro m
my hp has dropped to 486rw. i know that cylinders 1 to 6 seem to be rich as hell due to wet plugs. number 7/8 were nice and tan.
the air/fuel dropped into the 9's at about 5400 rpms. fp=38
this was after the spyder/50 change over.

it seems like the 50's might be to much. by the way this was on 14lbs boost.i noticed he is lean up above. i am also running 8.25 compression on mine. the fuel pressure was set at 38 with vacuum off then about 32 with it on. if i set it to 42 pressure it will not even idle very good cause it is loading up with fuel. you can smell it out the exhaust.
so as of today i went back to the 42's and gonna do the fp up again. will get another dyno later and let you know the results.

has anyone ever heard of any problems with the spyder intake?

also i like to drive my car a lot on the street and i have purchased some aft 205's. am i gonna like them ont he street. these are huge.? i am running cogs now and the boost is 15 lbs.

well thanks for the help.

[regattacoupe]

nasty, a friend has a set of AFR 210's on his 355 with a mild cam and runs like a scalded dog. Those heads are just right! ;)

[Forcedpower]

My 205s have been great. Like you I drive my car a lot on the street. Was a little worried that my low end might not be that great with my heads and intake but its fine. My numbers suck now but I hope once I get the mass air fixed they will go to over 500rw.