Maf count troubles

[VA-Mach1]

99 GT Vortech V3 Si with CXRacing FMIC.

Ford Lightning 90mm MAF and 42lb injectors.

1st problem at the dyno: MAF counts jumping by 100 counts? IDK what this means. Tuner tuned it anyway. I runs like crap. Tuner said to change to a blow through MAF.

So I did. Had a bung welded on the intake pipe before the throttle body and installed a SCT BA5000 MAF.

2nd problem today at the dyno: MAF counts to low at idle, car stalls? Tuner says he can't do anything with it. Doesn't know what the problem is. Reinstalled the first tune.

Got home and checked all the MAF wiring, and MAF voltages. All checks out well.

I'm at the end of trying to figure it out and thinking about just returning everything to stock.

Any ides for a salution?

 

[01yellercobra]

Find a new tuner. The first idea was a good one. I'll only run a blow through MAF with centri set ups.

I ran a BA5000 in a 3.5" pipe with no issues. It was one of the easier set ups I had to tune. So I'd look for a new tuner.

 

[DSG2003Mach1]

Sounds like a crappy tuner

 

[98 svt]

I'll echo the posts above.
Find a new tuner.

 

[VA-Mach1]

I don't think I did, but what if I wired the maf sensor, and sensor return backwards?

 

[01yellercobra]

Did you cut off the factory plug? I used an adapter for mine. I'm sure it would give weird readings if you did, but a decent tuner should be able to give you an idea what to check. Double check your wiring then start looking for a new guy.

I've never heard of MAF counts being too low. But I'm not a pro. The first time was probably backwash. I had that on my first set up and it caused all kinds of issues. I switched to blow through and it was night and day difference. Way easier to tune as well. My final set up was the BA5000 and aside from my stock eaton that was the easiest set up to tune.

 

[VA-Mach1]

I made my own adapter from a Maf extension, and a 05 plug from a junkyard. My IAT is still on it's own because it was already like that being it is a 99. I wired it using the pic here. I'm sure it's correct, but thought I would list it just to make sure.

 

[VA-Mach1]

Yes the first time the tuner said it is backwash, and the MAF is counting the air twice?

 

[VA-Mach1]

After reading on the sct website it says the sct ba5000 is for 400-720 rwhp.

With my setup I'd be VERY lucky to reach 400 rwhp.

Maybe the vmp would be a better choice? Vmp says it's good for 300-750 hp in a 3" tube.

Anyone think this may be the issue?

 

[01yellercobra]

What size tube is the MAF currently mounted in?

 

[VA-Mach1]

3" tube that came with the CXRacing kit.

 

[01yellercobra]

You should be fine. I ran mine in a 3.5" pipe and it was fine in the lower end. The power limit also depends on the size of the pipe. The larger the pipe the more power the sensor cansupport.

 

[jaxbusa]

Is there a bypass valve or blow off valve close to the MAF?


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[VA-Mach1]

Is there a bypass valve or blow off valve close to the MAF?



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Bypass valve is about 10-12 inches before the newly installed slot style maf.

 

[jaxbusa]

The connections seem right but you should double check. Did you crimp or solder the connectors?


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[VA-Mach1]

The connections seem right but you should double check. Did you crimp or solder the connectors?


Sent from my iPhone using svtperformance.com

Did a actual measurement when I got home. The maf is 10.5 inches from the bypass valve.

I soldered and used heat shrink when I made the adapter. Also checked ohms, and continuity on all the wires on the adapter. Everything is good with it.

 

[VA-Mach1]

I ordered a VMP 5000 maf. It should be here tomorrow. I'll install it and get another dyno appointment and see what happens. If it does the same thing I'll flip the maf sensor + and - and see what happens. If one of those 2 things don't work I just don't know what else to do.

I did try to get in contact with another tuner but I only have 2 that I know of in my area.

 

[Blown38]

Where in VA are you?

 

[VA-Mach1]

Where in VA are you?

Richmond area.

 

[01yellercobra]

So the bypass is installed after the intercooler?