rotorhead

ok, i've been having some tuning gremlins. i think(i hope) i've narrowed it down to some relay related to the fuel pump. something near the brake pedal? is there a way to bypass this thing, or where could i find a replacement? thanks for any help, folks!

JimmyHat

Yeah, I get those damn gremlins all the time. My car died one day day going to town. So I messed with the thing for days and it would still keep dying. So I bought a new fuel pump regulator from Mazda. Costed me $60. I put it in and connected the wires and checked it with the volt meter and it read the same thing it did with the old one. But insted it was some if not all the wiring was shot i guess. But yeah, it's a black cylinder relay thing under the dash right above the brake pedel. But if u need a new relay I got one I could sell ya pretty cheap. BUt anyways hope u geter fixed

rotorhead

jimmy, i might have to take you up on that. let me dig around there and see what happens. here's what's going on: around the same time i put my dellorto on i changed all kinds of stuff. all this time i've thought that my carb settings were off( which to a degree they probably are). it accels smooth, decels smooth, and constant throttle gives a weird stutter. i put a fuel pressure gauge on there, and either it doesn't work, or sometimes, my psi drops below 1. the car still hauls butt, and i'm getting a tad confused. i did notice the other day when i depress the brake pedal, the pitch of the fuel pump changed. i've also put a holley red pump on there, same deal with the psi. i thought i had a bad pump, but perhaps it was something else?

JimmyHat

Damn, that does sound weird. It sounded like to me that your pump was messing up, but u said that u had a holley on there, and Im thinking that if it was that, it should of worked. Well I really don't know what the hell it could be. Maybe your fuel pump relay. OR......If you have a Haynes manual, look on page 255. The top pic has a pic of a gas tank with all the lines coming out of it. Well there is a white plastic thing which is called the fuel cut valve. There are little metal ***** that roll around in there, I dont know what exactly they're for, I think if the car rolls over those things roll where the fuel wont keep running out so your car wont explode or catch on fire or something. But anyways, I was over at the mazda dealership and asked a mechanic about my problem, and he said that if the pump is working, it could be either the fuel pump relay or sometimes those ***** (hehehe) get worn out or something and they get stuck where the fuel comes out. So what I did was I took the fuel cut relay out and put another fuel filter in its place. But unfortunatly that wasn't my problem, but it could be yours, and it would be a very cheep fix. But just make sure u got the filter going the right way. But if your car rolls over and it catches on firem then you didn't get the idea from me.
But if that doesn't work, then e-mail me at TheRedFlasher12@cs.com and we can work out a price for that relay.
Kyle

rotorhead

LOL, jimmy, i couldn't blame you for my fiery demise! besides, i already took that out the first time i had my holley in there. from another post, it seems my holley may have blown my relay. yeesh! it shouldn't be this hard to hook up a fuel pump! maybe the fumes are getting to me

JimmyHat

Kool rotorhead. What ever the hell it is, I sure hope you get that thing workin again. Its a pain in the *** when that happens.

Pele

iTrader: (28)

Brake lights. Some people notice the fuel pump noise change when they have their turn signal on. It's teh slight voltage drop as the alternator doesnt put as much power out at idle as you need. Not too big of a deal... If you have extra lights, (Fog, driving or other) a nice stereo, or other electrical add on's, You may want to consider upgrading to a larger alternator and upsizing the battery.

See if the fuel pump noise changes when you turn on the headlights at idle.

rays1stgen7

I realize I'm replying to an old post, but I'm pulling my hair out. I've got those very same gremlims in my 1st gen. Press Brake pedal and fuel pump cuts out, take foot off brake, fuel pump starts up again. Bizarre. Trying to find a replacement brake relay. However, I'm beginning to suspect it may be vacuum related. Air control valve? Any thoughts?

enigma32

Brake relay? You mean the fuel pump relay?

I'm not sure how a vacuum problem could affect the fuel pump...

You sure it's cutting in and out? What's your voltage gauge do?

rays1stgen7

Yes Enigma, I did mean fuel pump relay. Sorry. Thanks for your reply. I think I've traced the problem to a bad ground on the plate lights. Damn thing screwed up all kinds of stuff. Nothing major. ( I hope) Whew!!

enigma32

Damn those crazy grounds... hehe

Glad you got it figured out

V8kilr

I did a whole writeup on this.

You cut 1 wire, if you hear the relay click then
*BAM* *BANG* *KABOOOM*
Problem solved