Ford Mustang Forums banner
1 - 20 of 36 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 · (Edited)
Hey guys I'm new to the forums, and not sure if this is right section. Forgive me if its not.

So here's my situation. I installed an on3 turbo kit on my 91 5.0. 67mm turbo 42lb injectors blow through PMAS 255lb fuel pump ect. I took the car to a local shop to have it dyno tuned. After sorting out some issue's (faulty injector, stuck wide open) we got the car to run, idle, and pull good up to about 4000rpm's. After that the afr's become to lean. Around 13-13.2 to about 5800rpm. All these tunes were done on wastegate spring pressure around 7psi. Now my tuner says that the PMAS is maxed out. That the ecu is reading the PMAS and its faulting out and he can't adjust it anymore. Now these are not exact quotes but has anyone else experienced anything like this before? If the PMAS is in just say 180 degrees off could this be my problem? Could the fact that he was reading the afr's off of the crossover pipe instead of the downpipe be effecting the reading? Any help would be appreciated. Also he thinks I should convert to a lighting 90mm MAF off the inlet of the turbo, and this would solve my problem.

Setup
Stock bottom end
Tw 185 heads
1.6 rockers
e303 cam
65mm tb
cobra upper and lower
also have a catch can setup on the car.

The car made 405hp and 455tq which i thought were spot on, but I would think the car would make more power because of the lean condition.
 

·
Registered
Joined
·
444 Posts
i am by no means a tuner but how come u couldnt turn up the fuel pressure to kill that leaning out on top and slow the injectors down low?
i use a c&l blow thru locked timing and use fuel presure to controll my afr one pound makes a huge impact
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #4 ·
At first, he didn't touch the fpr and it was really lean at 3800. He did turn it up to get it to where it is now. I didn't get to check what the fpr was set at though. I was actually not there for most of the dyno only the last few pulls. Also forgot to add it has a b&m fpr, and he's is tuning with a SCT chip
 

·
Registered
Joined
·
448 Posts
Mine faces the fender, with the airflow arrow pointing the direction the AIR FLOWS, which is from the ic to the t body. A pmas shouldn't be that different. I assume you welded the flange on? If so and you did it wrong your maf will be in backwards. That's an easy fix just cut the pipe, re-weld it and then bead roll the other end of the pipe. then, try again. As for the injectors were they purchased from on 3 as well?
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #9 ·
Ok mine faces the right way then. As for the injector's yes they were ordered from on3 with my turbo kit. We had to order an injector from ford (lighting 5.4 supercharged motors came with green top 42lb) , because cylinder one's was stuck wide open. He actually advised me to replace all of them with the lighting injectors. So I may do that soon. It scares me to think that one of the others could do the same. It was dumping so much fuel it actually locked the motor (just cranking with the starter). Luckily it didn't damage anything but it did cost me $119 for an injector and about $150 in labor
 

·
Registered
Joined
·
1,977 Posts
I got the on3 42# injectors also there Bosch...Hope mine work....:crying:
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #16 ·
How much straight pipe is in front of the maf sensor?
I would say a good 12"


@sweat90lx I asked if the factory injector would flow different, but he said that shouldn't matter.


Does anyone think that where he was reading the afr's could be a problem? I mean on3's kit has the bung welded in the downpipe AFTER the turbo for a reason. Where he was reading is going to only get a reading from bank two it seems. I'll check fuel pressure today and see what its at. At least I can drive the car now and break in the clutch :bs:
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #17 ·
If anyone is not familiar with on3's setup here is a picture. To the right of the flex section is where he had his wideband. If you ask me its not accurate. I'm still not sure if that would matter when it comes to fattening it up in the higher rpms


 
1 - 20 of 36 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top