mygt500

I think its the BAP...what number you have it at now? if less then 50 just turn it up to 50 (max).....check the wires that go to and from the BAP and TacoBill has a install thread on this to poss help you diagnose the problem and narrow it down to the BAP or the fuel pump......since its the stock fuel pump, fuel filter, and you added the BAP....I bet its the BAP...you know how amp's for car audio can be "quirky" when cold and just dont sound right until everything is warmed up at bit?...its usually a ground or loose wire that when cold can in some way be affected hinderng the performance link to follow.....could be a faulty BAP


https://mustangforums.com/forum/2005...ll-w-pics.html

Jersey Stang

I agree with you. I purchased a fuel filter cos i'm about due for a change. It's been at least 30K miles. Replacing that may help...but certainly not hurt.

Thanks for the link. I installed the BAP using Tacobill's write-up. I've always had it on 50 (rich) but now I notice that the **** will do a full rotation and a half before I feel resistance. It should only turn 270 degrees...not 540. I might have to take apart the small control box to see why it spins so much. I'm curious as to why it would suddenly stop working. If it is defective, how would I go about testing the BAP? What voltage should I get at idle? Shouldn't the voltage be greater under acceleration and load conditions? How would i test that?

Simon1

If it was a filter it would do it all of the time.

I think it's a tuning issue. Two of the dififerent timing tables our cars use to determine how much timing to be running is based upon the heat of the motor. There is cold based timing and normal temp timing. The cold based timing is set up so the car does not run hardly any timing while it is cold. After the car reach safe operating temps it will run as it normally does.

You could call and ask brenspeed and they would probably tell you it's normal or ask for a data log and they would adjust your tune.


My car runs exactly as you've described, except I can't hear the fuel system over the exhaust.

Turning up your BAP may increase fuel pressure which could give you more fuel while driving at WOT or tip in.

Simon1

If you have the stock system (fuel pumps and FDPM) and a BAP, generally a problem with any of the three would result in a consistant loss of power or run lean under boost.

You could check the wiring on the BAP but I still think it's a tune issue.



If you have twin pumps you can unplug each FPDM one at a time to see which one is working properly.

Jersey Stang

I didn't orginally have this problem. if it was tune related, should I be able to reload the tune, and the problem would go away? I will try that and also contact Brenspeed. I have it on a conservative tune and never tried the more aggressive tune thinking the current lean condition would be amplified and blow a rod. I put in a call to Brenspeed too. Maybe they have come across the same issue.

It finally stopped raining so I'll see if I can check it out before it gets dark.

Thanks everyone for the ideas. I'll check them all and let you know what helps.

Simon1

Probably. If you reload the tune in theory it should be just fine if the original tune is still good. Remember the handheld is like a computer and just like any other file loaded and unloaded it can be corrupted etc.

I had a tune go sideways on me out of the blue for no damn reason. All the sudden the car would cut out at 4,000 rpms with no fuel. Then the computer compensated for the lean condition after a few experimentations and ran really rich under WOT. I told my tuner all these symptoms and I was freaking out. He told me to shut my trap and load up a tune he was emailing me. A new tune and several data logs later and I'm doing good.

The easiest way to diagnose the problem is sending a datalog to a tuner. With that info, they can look at the numbers and tell where to you look for your problem if it's mechanical.

Best of luck and let us know.

Ultrashock

I would have to say it would either be the tune, filter, or pump. I was having problems like so around 15k on my car prior to tuning or any mods. I changed the filter and haven't had problems since BUT it could also be the pump. There is a TSB for it. Do you experience hesitation...especially after long highway drives? If so then I would point towards the pump. I'd start by changing the filter and running some 93 from chevron/lucas injector cleaner to see what that does.

Jersey Stang

I immediately thought about the pump tsb, but I don't have any hesitation during a long cruise. My car works better after a cruise cos everything is at operating temp. I think my biggest clue is the very loud and high-pitched tone i hear coming from my BAP during a cold start. I work night hours and don't have a garage to work in during all this rain, but I'll try many of the suggestions you guys mentioned. Thanks for the help.

mygt500

Let us know what happens Jersey

mxg30

Hey Guys,

You're way over thinking this.... Always start with the simple things. I had this same exact same problem. I simply cleaned the Throttle Body and all was normal after that. It would not be wise to start throwing money towards what may be a simple solution. Takes only 15 min. Also note that our cars are very sensative so it doesn't take much build up to cause this problem.