Besides changing out the fuel filter. What else could cause this?

Currently using the Racetronix setup with their wiring kit.

Gauge

 

1. Under what conditions does this occur?
2. Has it been a problem since the change to the new pump/wiring?

 

1. The video was at the 1/8 track.
2. No

I started noticing it after I changed my tune. I orginally scaled my injectors. Now I have the correct numbers in my IFR table. I also descreened my MAF as a test. (Screen is going back in)
I went to the track to tune my PE. And couldn't get my AFR down below 13.xx above 5600 rpms.

I actually thought my wideband was wrong because I didn't get any KR.

And just 2 weeks ago on my old tune. My AFR was 11:1 at the dyno. :dunno:

 

Your fuel pump is probably going bad if you were not loosing pressure before...How long abo did you install it? A while back there were problems with failing pumps from racetronix. They have now fixed the problem.. I would not do any more WOT runs untill you have fixed it...

 

I bought it in 08/2004 when they first came out.

That would suck if it is the pump. I just installed it last year.

I am going to change the filter first.

 

I agree. And, if the pump is not taking a dump, could it be the connection to the out tube on the hanger?
I've seen that happen on several turbo BUICKS..the hose that connects the pump nipple to the hanger tube leaks.
I've also seen the install go bad when the OEM noise attenuator is re-used to connect the pump/hanger tube, instead of using the hose and clamps...

 

Crap, I don't think Racetronix sells just the pump.

 

Some pressure drop is normal when supporting high HP numbers if you are not using a FM FPR system. You may also be beyond the HP support range of this system.

If you suspect your are having problems please contact your authorized Racetronix dealer for technical support.
You will get faster accurate info on diagnosing your problem and be on the road to a solution much quicker this way.

Thank you

 

droping to 25 psi is not normal...

 

Racetronix F99 systems have nothing in common / to do with the C5 systems.

There was no problem to fix and this information is nothing but rumor spread by a small handful of misguided people.

 

New motor and now this, along with the bad plenum and low boost, looks like you got that taken care of, you got to be bumming now.
Watched the video
Its even low at idle, mine sits around 60 and and with WOT might drop to 53-55. I would defiantly try a new filter. Just curious when you last replaced it did you drop the tank or do the "Hatch" method. If thats not it I would say time for a new pump, or maybe you will get lucky and find a leak which might count for the low pressure at idle.

 

Dropping to 25psi could be:
-dying pump
-pump pickup is/or came off

etc.

Pickup might have worked it's way off.

 

If the filter doesn't change things, you probably need to look to the in tank.
Hawk

 

Well two weeks ago my AFR was fine. With Nitrous I know I am at my limit which is why I plan on adding a BAP. And as soon as you release a FM FPR I will add that.

If it is the pump, do you sell just it??

 

Your making too much HP for that single pump.It's a very common problem.We run out of fuel volume at about 550-580rwhp on M6 cars ussing there pump and might get 600rwhp with a BAP. Time to rethink your fuel sytem.

 

I dropped the tank. Guess I will be dropping it again.

 

I didn't think 526 rwhp would be too much for the pump.
That vid was a boost only run.

 

With an A4 it can be.Also in cooler weather the car will make alot more HP which means it needs more fuel.Thats a big problem out here when people do there setups in the summer(85 degree) and they totally lean out in the winter at 40 degree's.

 

Changed the filter. No change, has to be the pump. Still no answer from Thunder or Racetronix.

 

Thunder nor Racetronix would intentionally ignore your support request.
Perhaps you should try again! Call Thunder directly if e-mail is not working out for you.