[WooMach1]

So i got some parts from American Muscle for my 2003 Mach today and installed them all this evening. I installed some NGK Iridium IX Plugs, and 90mm Lightning MAM, and a new fuel filter. Everything starts up great, idles fine, everything sounds normal. The only thing is everytime i go WOT it seems sluggish at first. Like ill mash the pedal and it almost seems to bog a little and then pick back up to its normal power. This hesitation got annoying, i tried messing with the tune with my SCT tuner but nothing seams to really help. Anything thoughts???

[zinsavage123]

why you get a 90mm maf for no reason? prolly reading too much air coming in.

[WooMach1]

I have a JLT RAI and the intake was shaped like an hour glass with the stock MAF. It looked ridiculous. And with the new 90mm on it actually looks normal. Plus i plan for alot more power here in the winter and decided why the hell not.

[zinsavage123]

yeah but still FOR NOW its not needed I would put the stock maf back on till you reach the time to put it on with future mods. that thing is reading too much air coming in and prolly cant compensate fuel I would think?

[WooMach1]

ives seen other people with Mach 1's N/A with very few mods like i have and they dont seem to be having the same problem :/

[zinsavage123]

hmm I'm just saying if it ran fine before, and now after some change of parts either its the parts or something was installed wrong ya know. Get a new tune and tell your tuner the size maf so they can send you a retune to compensate some fuel for that big maf.

[WooMach1]

Yeah i was just thinking that, i was hoping i might have been able to have the MAF on and then when i was ready, go get a tune for it but, i guess i have too now :/ oh well its a forces positive i guess lol

[1LOUDGT]

Have SCT send you a new tune. Did you check the gap on your plugs?

[WooMach1]

all plugs are gapped at .054

[TRMach1]

Originally Posted by WooMach1 all plugs are gapped at .054

The proper gap for those plugs on your motor is .052, but I doubt that's the problem. That 90mm MAF is way too big for a stock/minor bolt on Mach 1 motor! The stock one is 80mm, and the largest aftermarket unit that can be used without causing the kind of problem you're encountering is the 85mm one that comes with a C&L intake kit. 90mm and larger are meant to be used with forced induction, and usually require some kind of electronics upgrade to the mass air sensor also, like a SCT BA2300.

[WooMach1]

I find it confusing then that I've seen Mach 1's with the 90mm with no power adders but haven't hear of then having problems. So let me ask this, if I were to get retuned with the 90mm would that solve my problem? I really wouldn't like to have a $200 paper weight sitting in my garage for the next 6 month, even if get no horsepower gains I'd rather have it on then not. But if it's going to grain my power I'll take it off and wait until the winter when I boost it. But again if I can I'd REALLY like to leave it on, I hope a tune is all I will need.

[1989Gt.]

Originally Posted by WooMach1 I find it confusing then that I've seen Mach 1's with the 90mm with no power adders but haven't hear of then having problems. So let me ask this, if I were to get retuned with the 90mm would that solve my problem? I really wouldn't like to have a $200 paper weight sitting in my garage for the next 6 month, even if get no horsepower gains I'd rather have it on then not. But if it's going to grain my power I'll take it off and wait until the winter when I boost it. But again if I can I'd REALLY like to leave it on, I hope a tune is all I will need.

The maf will require a tune if you are going to leave it on, Its too big for what you have. Like stated before its meant for power adders

[TRMach1]

A retune may, or may not fix your problem. There might be enough wiggle room in the stock MAF sensor to help, but I doubt it will solve it completely. You're running a JLT RAI, which is like a 3 or 4 inch diameter tube, compared to the stock 2.25 inch diameter intake tube, plus the 90mm housing. It could be pegging the stock sensor on WOT, and tuning around that might be really difficult. If you're going to be building up the motor over the winter, I'd put the stock MAF housing back on for a couple of months and keep the larger for one for when the build is done.

[WooMach1]

Im not sure if you've came across my other post of a goal of having 400+ crank horsepower, I'll be doing a upper and lower intake porting, php spacer, 96-98 cobra intake cams and a few other things. Would the 90mm be useful then?

[Mach Boy]

The reason your car is running like crap is because it needs a retune, period. You can't swap the MAF without retuning the car unless the MAF is programmed to run with the specific injectors that you have. If it's a 90mm Lightning MAF then it's programmed for 39lb injectors. Take it off and put the old one back on until you can get it retuned. And like the others are saying I'd wait until you have some more mods until you spend the money to have it tuned.

[AMChrisYoung]

Originally Posted by TRMach1 The proper gap for those plugs on your motor is .052, but I doubt that's the problem. That 90mm MAF is way too big for a stock/minor bolt on Mach 1 motor! The stock one is 80mm, and the largest aftermarket unit that can be used without causing the kind of problem you're encountering is the 85mm one that comes with a C&L intake kit. 90mm and larger are meant to be used with forced induction, and usually require some kind of electronics upgrade to the mass air sensor also, like a SCT BA2300.

Originally Posted by TRMach1 A retune may, or may not fix your problem. There might be enough wiggle room in the stock MAF sensor to help, but I doubt it will solve it completely. You're running a JLT RAI, which is like a 3 or 4 inch diameter tube, compared to the stock 2.25 inch diameter intake tube, plus the 90mm housing. It could be pegging the stock sensor on WOT, and tuning around that might be really difficult. If you're going to be building up the motor over the winter, I'd put the stock MAF housing back on for a couple of months and keep the larger for one for when the build is done.

^^This^^^^


You have installed a MAF that is way too large for your application. I'm not aware of a tune that would correct your issues as is with the modifications you currently have. The more you modify the motor to take in more air(head work, cams, upper/lower intake, headers) and get it out more quickly, you will be able to use that MAF.

At this stage in the game, however, you would be better off setting it aside until you have modified the engine enough to warrant the need for the larger MAF.


I hope this helps! Good luck!

[WooMach1]

Alright so i switch back to the old MAF the hesitation went away. I am happy with the new plugs though! But its also going to suck having a $200 part laying around for 5 or 6 months :/

[WooMach1]

So just a little update, I got a tune from Bama Performance for the 90mm and the hesitation when away )))) Im super happy now. It does feel like it has a little more geddy-up but it could just wishful thinking. But other then than im just glad it works now