EFIDynoTuning Forum

I have been using the A9l2 for a good while now and my car runs great! Now for the problem i am having. I am trying to help a friend with his foxbody
and he has almost the same engine setup as mine. It is tuned now with the old XDF before the auto scaler using a PRO-M meter it runs good but we have tried a few times to move to a new HPX-E meter because I have the exact meter in my car and he has plans of more boost and new 331 soon.

What happens is the fuel error goes to 1.30 pretty quick! I copied my tune and changed injector info over to the DEKA 60's (What he has) and check the differences and it states the MAF is over a 1000 off up top even after I copy a few times to make sure. I started from the A9l2 base file followed steps from website in order and copied MAF from my tune (separate instance of TP) and same thing MAF doesn't match. What's weird is when just do show compare data its very very close but when you choose show difference that's what is way off

I load the old tune with appropriate XDF/ADX etc. goes right back to 1.02 fuel error.

Am i doing something wrong or am I fighting a bad MAF?

Attached are the 2 tunes i have not gotten in to the other aspects yet just the main values.

Thanks for the help!!

Does fuel error go to 1.30 at WOT? if so thats normal i think. At WOT fuel error is irrelevant, at that point youre comparing wideband lambda to commanded lambda.

No at idle can’t get past that with new MAF

the two tunes have the same maf transfer in them one has 60lb injector data and yours (current jacques) has 45lb injectors.

The tune files look excellent if its not running on that then his maf is different than yours. Not uncommon at all as there are several different hpx sensors.

That’s what I am stumped by he ordered the HPXE and same housing. I even went back on my order to make sure there the same. The only way I have I have achieved a close to zero error idle is add 20% ish to MAF but that takes the top of MAF to 5000 and know that’s wrong


My HPXE was purchased before they were supposed bought out.

Also forgot to mention he said he blew it out with air compressor I am guessing that’s not good for it.

no thats not wrong yall have two diferent mafs. No other explanation.

Edited ^^^

I changed the filter from a small cone to bigger cone style K&N and changed the aluminum C&L elbow to custom 4" elbow and had to change my MAF curve by close to 10%-12% to get it right. So keep in mind that those things play a huge factor in the transfer curve.

Yeh. The thing that’s getting me is both cars have power pipe 85mm pmas housing and HPXE meter didn’t think it would be 30%
May just add to MAF and see if the error is consistent through curve

if camshaft, intake, heads, exhaust are different then that also has an affect. anything thats changes the airflow in the engine can and will have an affect on the maf transfer curve. theres a lot variables besides maf, filter and intake tube setup. something to keep in mind is an engine is a big air pump.