Couple quick questions b4 the track tonight!

[1jimmy__d]

I'm going to the track tonight, the first time with nitrous but had some concerns. I just changed the fuel filter and filled the nitrous tank.

1)I hear a high pitch (iiiiiiiiiiiiiiiii) from the rear of the car when the car is idling. Is this the fuel pump going bad?

2)Will this affect the way it runs at the track (with and without nitrous)?

3)Will the nitrous work at all if the pump is going bad?

4)SHould I have it changed somehow b4 i go to the track tonight?

5) Anyway I could do it myself?

Thanks,
Jim

[RPM427]

It sounds like the fuel pump. They will make that noise before they go bad. Is a stock pump or a high flow one? If you do not have fuel pressure saftey switch installed, the nitrous will grenade your engine if the fuel pump decides to quit. If you do have a saftey switch installed, the nitrous will just turn off.

Pumps don't always go bad when they are making noise, just sometimes.

[bigred90gt]

I have had my mustang since Nov. 200, and it (the fuel pump) has always sounded like a leaf blower. It is so loud that I can hear it over the radio if it is not at deafening volumes. To this day, it hasn't quit on me. But every car is different.

[1jimmy__d]

I dont think i have that switch if its aftermarket. But the pump sometimes makes the noise and sometimes doesnt. When i just drove it it did not make the noise. Would the nitrous when sprayed put pressure on the fuel pump and cause it not to work? Im going to the track at 5:30 tonight. What do you think????

[Lethal5Oh]

Id check the fuel pressure. See what it is with the vacuum line attached and detached. My pump was making the same noise, and i found the fuel pressure was low. Check it out. Best to find out the easy way than the hard way infront of every one at the track.

[1jimmy__d]

where is the vacuum line and how can i tell if the fuel pressure is low? Even if it is making the high pitch noise, should the nitrous still work when sprayed????

[chris91LX]

I've had really noisy fuel pumps, no big deal. The only question is, depending on the size of the nitrous shot your running it may be a good idea to have a bigger pump. What kind of kit is it? Some of the nitrous kit's have a fuel pressure cutoff relay that shuts off the nitrous when the fuel pressure is low.

[Lethal5Oh]

The vacuum line is attached to the top of the fuel pressure regultor. do you have a fuel pressure tester? You need one to check the pressure.

[1jimmy__d]

oh boy!! I went to the track and it was terrible. I made two runs and both of them, the motor bogged down at high RPM's. I hit the nitrous and it bogged even more ;terrible and a big puff of black smoke came out. Not good. This happened twice. I turned her off for about an hour b4 going home. On the way home I decided to get on it to see if it bogged down. IT DIDNT!!! Crazy. I got on it a couple times on the way home, no bogging at all! I decided to push my luck and hit the nitrous again, and then it bogged down again. This tells me that it must be the fuel pump. But why would it run fine after it cooled down? Is the fuel pump easy to install by myself? Its in the gas tank right?
Very pissed off for making a wasted trip to the track

[ultraflo]

What nitrous system are you running? A bog and puff of black smoke sounds like an over rich condition... you need to make getting a fuel pressure gauge a priority, along with an adj. regulator. And which in-tank pump are you running? What HP jetting do you have the nitrous system set-up for, is your jetting correct? (double check to be sure)

I've been in numerous mustangs with loud fuel pumps, that souldn't be a big deal, run a hobbs switch (fuel press. safety switch) if you're worried about the pump... or get a bigger pump (depending on what you run now).

The Magnaflow pump I run is all you can hear when the car has mufflers on it.... loudest damn fuel pump I've ever heard, and it works great.

BTW, what plugs are you running and what are they gapped at?

[1jimmy__d]

its the NOS stage 1 kit from jegs. it has 80 hp per shot. i believe the fuel pump is stock. im not sure what the plugs are gapped at, and i believe the timing is at about 10 degrees. I imagine i need more flow (bigger pump). Is this an easy install, and do you think this is the next logical step to take? Thanks for all replies. This sucks!

[Lethal5Oh]

You can do the pump yourself. I did it myself. Make darn sure your tank is empty or darn near it. I made that mistake and its a major PIA. Im not sure about fox bodies but i needed a special duckbill tool to remove the lines from the tank. If you have a freind to help lower and raise the tank it makes for a much easier job. Good luck.

[RPM427]

Check your spark plug gap!!! If you have a stock igntion you will need to gap them to about .35 instead of the regular .6 . It may also be wise to get plugs a degree colder as well.

[1jimmy__d]

I will check the gap. Would the gap cause the car to do these "symptoms" as described. If so, would I be better off just changing the plugs and not the pump, or do both?
Are there any other tricks to changing the pump. My understanding is undo the 2 straps lower tank. The pump should be on top. Pull out and replace same as it was. Sound right? The shops around here want 300 dollars to do it!!!

[Lethal5Oh]

Only "trick" to the pump is to get the clips freed. Its either duckbill clips or hair pin, im not sure which is on your car. Id test the fuel pressure before you go replacing the pump. Why do it if you dont have to. Unless you need a bigger pump for the NOS?

[ultraflo]

I'd recommend a new set of Autolite 24's and gap 'em at .035 to start. Next you need to get a fuel pressure gauge hooked up, and it wouldn't be a bad idea to get an adj. regulator, but I'm not sure you even need it yet, it's highly recommended that you monitor your fuel pressure while spraying nitrous. Or suffer the consequences... You shouldn't need an aftermarket/bigger fuel pump for the stage one kit, but it doesn't hurt to have a bigger pump for future mods.

I'm sure your plugs are part of the problem... hard to say, need to know whats going on with your fuel pressure.

[1jimmy__d]

ok, i have the fuel pressure results. it is 32 psi at idle and 40 under load. it turns out that i have platinum plugs in there now. i bought the suggested autolites and will install tomorrow. Is the fuel pressure at good levels, or is the pump bad? Thanks again!
I really want to run the nitrous at least once this year!!!

[jbakes]

It sounds to me like your getting too much fuel. If it is bogging down then smoking tells me there is too much fuel. I am assuming that you have a wet kit am I right? If so, check to make sure that you are spraying NOS. If you arm the system and trip the WOT switch it tell the sylenoids to spray extra fuel and NOS at the same time and if for some reason the NOS is not spraying it is just going to dump a bunch of uneeded fuel to the throttle body making your car WAAAAY rich. Check that. Close the bottle and arm the system, check the sylenoids bye putting your hand on it and tripping the WOT switch. You will feel it click if it is working. I am gonna bet that is your problem. BTW get rid of those platinum plug with the n2o, bad combo. N2O does not like platinum, they react to one another. I just finished my NX kit and put motorcraft plugs in gapped at 35 with timing set @ 11 with 75 shot. Runs perfect. gonna jump to 100 shot tommorow then bye the end of the weekend shoot it with 150.
Your fuel pressure sounds fine by the way.

[1jimmy__d]

it is sprayin the nos bc i went to fill the tank and it was practically empty after hitting it a bunch of times to see if it worked. I had two successful sprays when it was first installed. Then all this crap started happening. If the fuel pressure sounds good to you, then i would have to think it is the plugs (I hope)! But why then would it work the first two times?? 32 is where the fuel pressure should be at? Now remember that it has done the jumping at high rpm's w/o the NOS too. Not nearly as often, but it has done it. I am HOPING it is the plugs.

PS i do have a fuel pressure safety switch on it. it came in the kit. It is the stage 1 NOS from JEGS that sprays in the TB.

[1jimmy__d]

Thanks you to ultra flow and the rest who responded to these posts. I installed the plugs today (PAIN IN THE A**), and hit the nitrous to see what would happen. Well it worked FANTASTIC!! I hope it continues to work (knock on wood). Keep your fingers crossed. I guess the fuel pump is still good. Thanks again, now i can go kick my friends z28 in the 1/4 mile!