30lb injector woes

CManT1914

New Member
Feb 5, 2004
3,172
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Killeen, Texas
Okay, I'm starting to get a little frustrated. I got my Pro-M back today calibrated for my 30lb injectors. I put it on and drove around a bit. It's definitely running better, and it will spin them into 2nd, but not like it should. It's still running SOO rich!! You can smell the unburnt gas from the exhaust. :( Is this typical of running 30lb injectors? I mean this thing is a slug when I get on it, it just doesn't scream like it should. Everything mechanically is sound, fuel pressure is at 40psi vacuum off. I'm thinking maybe with the big injectors I just need a dyno or tweecer tune? It actually idles pretty good, the idle surge isn't near as bad as it was with the C&L on there. But it's running so rich!! Do 30's typically give these kind of problems without a tune?
 
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i'd expect the rich condition without a custom chip or tweecer, i went from 250-something rwhp on the first dyno pull to 280rwhp from just adjusting the air/fuel with the SCT chip. you could try backing the fuel pressure off a couple of psi though
 
I HIGHLY doubt your rich at idle. If you were as rich as you think, you'd be surging/stalling like crazy. Any car with an offroad h pipe will stink and it will probably get worse with a cam. You can't expect it to be perfect relying on just the "calibrated" maf and eec. If your having tune problems, i'd invest in a tweecer or a pms and a wideband. The pms and wideband are 2 of my best purchases.
 
you can try backing down the fuel pressure a bit. (even though i wouldnt go much below where it is at now). that is the band aid solution. if you want the right solution, you need a custom chip or twEECer tune. if you go with the tweecer, i will send you the bin file i was using with my combo to give you a good starting point.
 
from kenne bell:
Can I change mass air meters? By far our number one complaint. A larger mass air meter theoretically makes more HP if the one you have is too small for the engines air flow. If it isn't, the HP increase is "0." Factory engineers spend considerable time calibrating their engines to a specific computer. Then someone "just sticks on a new meter?" No, No, that's not the way it's done. The computer must be re-calibrated and never, never, ever install a meter and larger injectors without re-calibrating the computer or installing the proper re-calibrated chip. METERS CANNOT BE "RE-CALIBRATED" FOR LARGER INJECTORS. Changing the voltage signal to the meter via "re-calibration" by the supplier or with "adjustable knobs" only compensates for the larger injectors at wide open throttle. The computer load tables and transfer function is also adversely affected. The timing is advanced. We've seen up to 52° vs. stock 30° and lean, lean air fuel ratios - all at the wrong time. Anyone who disagrees might just check with Ford FRP or a Ford engineer.
maybe that'll help, good luck
 
A Huge majority of Pro-M meters are just plain 'whacked' i.e. the calibration is really bad. That's your problem, not the injectors. Like the one person posted from KB's site with a '94 and up, using a calibrated meter will throw off load calculations which will throw off timing, so you need a chip and tune anyway.

A tune will help your problem, but Pro-Ms that are that bad to start with are difficult to get decent driveabilty with.
 
I will be buying a twEECer VERY soon. I've been reading a LOT of information on tuning with it and feel very comfortable with using it.

The really strange thing is I tried backing down my fuel pressure, but my afpr wouldn't let it drop below 39 vacuum off. :scratch: It would raise the fuel pressure quite a bit, but it would never go below 39psi. wtf?

I know the injectors will work with my combo, I just was wondering if it was typical for a 30lb car to run this poorly without a tune.

Green 94, if you could send me that .bin file you were using that would be great. I'd like to compare it to my file and see what all differs between ours. I've made a lot of changes to a Cobra calibration just to see how everything worked, but without actually being able to write that to the PCM, it's kind of just playing around for now. :( Thanks guys!
 
Putting a meter and bigger injectors on our cars will require you to need a tune. Plain and simple. YES you CAN get away with it, but even if the meter is calibrated, your computer is still confused and you won't get the most performance.
 
Chris its like i said before man. I got my 80 and its supposed to be for my car specifically but it still ran like crap and will until i get a dyno tune. So its off till that time.
Which may be soon HAHAHA!!!
 
i need to boot up my laptop to send it to ya. ill post a link here when i have it hosted. the combo that tune was designed for was:

gt40x heads
ported gt40 tubular intake
trickflow stage 1 cam
bbk 70mm t/b
pro-m 77mm maf
24lb injectors

i will make all the necessary injector slope changes and maf calibration changes before i post the file for you. do you still have the egr and smog on your car?
 
Green 94 5.0 said:
i need to boot up my laptop to send it to ya. ill post a link here when i have it hosted. the combo that tune was designed for was:

gt40x heads
ported gt40 tubular intake
trickflow stage 1 cam
bbk 70mm t/b
pro-m 77mm maf
24lb injectors

i will make all the necessary injector slope changes and maf calibration changes before i post the file for you. do you still have the egr and smog on your car?

No EGR, no smog either.

I started with a Cobra calibration and did the following to it:

deleted EGR
deleted smog
set fan temps
set idle speed
set injector slopes
loaded maf curves
reset checksum base
a few other things i can't remember

But I may have missed a few things. When I did the maf curves, I used the maf info that came with the software. I have since got my Pro-M back with a new flowsheet, so I can load those later on. But I was a little confused about which computer and strategy to use. I went with the J4J1 (cobra tune) and the CBAZA strategy. I'm pretty sure that's the right strategy. :shrug:
 
bjl95mustang said:
chris that sounds good. well, if you want to drive down here you can load it in mine and see if your cas runs.

:nice: If you're not busy saturday, and I can get away from home for a few minutes I will do just that. :) Thanks Brandon!

EDIT: oh, lol, I completely missed your previous post.
 
Yeah you got the slopes in there, then go to the function MAF transfer and hit LOAD MAF the load Pro-M30. That is a good starting point just to get it driving better. Then when you meed up with bjl95mustang he can help you put in you MAF flow sheet.
 
It is all in your injectors...it will make you run rich. I have had a few of the symptoms present in the overinjected cars. Afterall...I have 30's as well:)

You will need a tune to take advantage of them. Without a tune on a h/c/i car the 30's are overkill.
 
WhiteDevil said:
Yeah you got the slopes in there, then go to the function MAF transfer and hit LOAD MAF the load Pro-M30. That is a good starting point just to get it driving better. Then when you meed up with bjl95mustang he can help you put in you MAF flow sheet.

Quick question: I was trying to enter the data from my flow sheet into the MAF Transfer function in CalEdit, but when I converted it to a 30pt spread, it got f***ed up. There was a huge spyke in it right around 2v. Either the conversion part of the MAF Transfer function works very well, or maybe I'm doing it wrong?
 
5spd GT said:
It is all in your injectors...it will make you run rich. I have had a few of the symptoms present in the overinjected cars. Afterall...I have 30's as well:)

You will need a tune to take advantage of them. Without a tune on a h/c/i car the 30's are overkill.

Yea I just hope my car running badly is the PCM not knowing how to handle all the changes I did, and not something more serious that I can't fix with the twEECer.