oK guys I need some help. I finally after 3 years of running a mail order tune with my set up LUCKED up and found a tuner in my back yard that seems to really know what he's doing but I want to run this stuff by you guys and get some opinions. I am WAY LEAN!!!! Every pull we did at about 3300 rpms My a/f went from 11.5 and spiked to 14.0......the lowest we ever got it at WOT was 13.1 and that was running so rich at 2500 rpms it wonted to die. So, trial and error we first put a new fuel filter on it and it helped but didnt even come close to fixing it! Then we put a fuel pressure gauge on it....Unfortunately I dont have one in the truck (obviously I have needed one) and the pressure stays around 40psi until you mat it....then it spikes to 50 psi and about 3300 where its leaning out the pressure drops to 30psi!! What the hell. So after discussing some things he decided that my stereo amps (have 2 that come on when the key is on) is pulling juuice from my fuel pumps and that is what is causing my pressure drop and the leaning out. So we ordered a kenne bell boosta pump that is supposed to correct this amp draw from the fuel pumps. He said he thinks this is what is causing it b/c hes run into this problem before with a L's and mustangs he's tuned. so my question is this....does that sound like a possible cause and solution? After I left (b/c we had been working on this thing for about 5 hours trying to dial it in and it was about 11:00pm) I thought well we could have pulled the fuses on the amps to shut them off and try another pull but we were both tired of working on it so i didnt think about it at the time. So, anyway Ia m thinking of replacing the fuel pumps also before I go Saturday to try agian with the busta pump but I need some advice from tuners for a second opinion. Is there anything else that can be causing my pressure drop that you can think of? Sal, i tried to call you today but I guess yall were busy. If you need to know my mods are....6lb lower, chickenman's cool-aid set-up, 90mm mass air, denso iridium plugs (which he also wants me to change to TR 6's before I come back sat), autologic chip (he's programming a diablo revolution for it now though), boost by-pass, 2001 intercooler upgrade, aluminum drive shaft, 3.73 gears, jlp thunderpipe. Guys please help with any suggestions or ideas you may have. Thanks I also read in a search that the fuel relay could be bad? How do I check that?

 

I had a truck with the identical problem this weekend in CA. Was also a 2000. I will tell you what I told him. Drop the tank and check the pump hoses. The 99-002 had the problem with the weak clamps that eventually cause the line to blow off. My guess is that one of your clamps is at the point where it can't hold the 50 psi and it's bleeding fuel back into the tank.

 

i would try the cutting the power to the amp thing first.

Secondly, the 99 and 00 have had issues with the fuel lines popping off one of the pumps. That could be your problem.

If your amps are pulling a ton of juice through out the whole system, then you may need an upgraded alternator. You might start noticing problems all over. The fuel pumps are one of the few operating systems that draw enough power to show problems when it's lacking. Everything else is fractions of a volt or slightly higher.

If you shut your stereo off and turn all your head lights, fogs, and running lights on, then turn on the stereo, how much do the light dim? That could be a good indication.

 

tallimeca, they actually dim significantly when the subs hit. We replaceed the fuel filter and just as good measure I ordered the Walbro 255 fuel pump kit this afternoon and we ordered the kenne bell boosta pump. I will check the lines here in a minute Sal and let you know, fixing to change the plugs. Any more thoughts guys?

 

if they are dimming significantly, that can definetely be your problem.

Not sure how or if the boost a pump will safely fix that, but the tuners can answer that better.

 

did you have your stereo blasting while on the dyno? if not, the amps are not the problem you are having. they shouldn't draw more than a couple of amps at idle. to verfiy, just pull the fuse you have by the battery on the power wire to the amps.

it is either a loose line or a dead pump

 

OK, didnt get to check the fuel lines b/c it took 4 1/2 hours to change the plugs!!! What was ford thinking?! But I'll get around to checking the lines and everything in the next day or so, supposed to so Saturday for another attempt to dyno tune it again after the kenne bell boosta pump comes in Thursday, I'm gonna go ahead and put the walbro's in just in case, my truck has 56k miles on it anyway so I'm sure it cant hurt to change 'em. Is 4 hours normal for a first timer plug change on this thing?! WTF! Seems like they could have found some more chit to put in the way.

 

thats normal.

when you put the pumps in, you might as well get a stainless y

 

is the best place to get one of those stainless "y" s ???

 

I got mine from McMaster-Carr. Here's the link to the exact item.

http://www.mcmaster.com/nav/enter.as...66&pagenum=117

-Nate

 

ok, sorry I havent seen the fuel pump set up and know nothing about it...yet. So what is the benefit of the "stainless" wye and what is the one currently in it? Could I get this locally at Home Depot or a plumbing place or something?

 

Some people have had problems with the line coming off of the stock plastic Y fitting. This has caused people to tighten the clamps down to prevent this, but they end up crushing the plastic fitting from over-tightening.

Take a look at this post for more info: https://www.f150online.com/forums/sh...light=mcmaster

-Nate

 

THANKS QUICkSILVER02, I'll look into that before I change my pumps.

 

Please tell me that it was your idea to suggest that your stereo amps were the causing the problem and we'll cut you some slack this time. Because if it was your tuner I would have fired the guy on the spot. I'm not trying to be a jerk, it's just that correlation just doesn't make sense and I would have trouble trusting anybody that thought that to work on my truck.

 

So what you are saying is that you think it isn't possible for an electrical system or circuit in a car to malfunction because of excessive draw somewhere else in the system?

Thank you sir for proving you don't know anything about anything. And if for some reason you do and are about to post some credentials on why you do think, you know something, you better go edit your post first. That is one of the dumbest things i've ever heard. Not saying this is that guys problem, but it's not out of the relm of possibility.