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Fuel pump dead?

Posted: March 30th, 2011, 4:03 pm
by _lithium_
Ok, the other day when I came to a complete stop at a light, I took off and thought I mis-shifted because the car nearly died and would barely take off and was jolting. Once my car got up past about 2500RPM it seem smooth and fine but any lower it felt really jolty and sounded like it wanted to die. Today, I went to my car and started it fine, backed up, and then it sputtered and died and will not start but sounds like it is wanting to start but just can't. Could this be a bad fuel pump? My gauge for fuel hasn't been working for about 6months and only works once I fill my tank up completely full and from there it will just drop to zero after I drive for about 40-60 miles.

I'm going to try and test the PSI here in the next few hours but what should the PSI be like and where is the attachment? I can't think of any other parts dying that would cause this but feel free to shoot.


Also, I'm not sure if this is even anything that'd matter or cause that (i doubt it) For the past few months, I've had to manually add coolant into my Filler cap every 3-4 days (only about 1/10 of a bottle at a time or less) but the Resevoir is just completely full up to the cap and won't be sucked into the radiator at all. What would cause this?

I drive a 1992 Mazda Mx-3 GS (V6) - no mods whatsoever

Re: Fuel pump dead?

Posted: March 30th, 2011, 4:30 pm
by Daninski
First off where do you live? Someone may live near you and might have a spare fuel pump to swap out just to see. When my fuel pump went it just died, my son had the same thing happen. Remove the fuel hose leading into the injector rail and point it into a container or plastic bag and have someone crank the engine over. The fuel should give a good solid spray so watch out. i would advise you just go to the wreckers and get another fuel pump assembly just be careful removing the screws on your car. Use lots of penatrant first and put a Philips bit into your ratchet/socket so you can really push down to get those screws out.
As for the coolant try replacing your rad cap.

Re: Fuel pump dead?

Posted: March 30th, 2011, 5:58 pm
by PATDIESEL
Not that Dan needs a +1, but I would check it pretty much the same way. Take the hose off the rail and crank the car over. Quick way to check for pressure.
PS- remove the gas cap to relieve pressure (then put it back on) before taking the hose off the fuel rail. Otherwise you risk a squirt of fuel in the eyes when remove the hose from the rail.

Re: Fuel pump dead?

Posted: March 30th, 2011, 6:08 pm
by _lithium_
I'll probably end up doing it that way, but my dad has a fuel pressure gauge and wants to use it lol. Where would one hook up on it?

Re: Fuel pump dead?

Posted: March 30th, 2011, 6:14 pm
by _lithium_
Does anyone have a spare Sending Unit (for the gas pump gauge in the car) that they'd sell to me? I'll cover shipping of course, just need one that works is all.

Re: Fuel pump dead?

Posted: March 30th, 2011, 6:26 pm
by Daninski
If the weather holds I plan on going to the picnpull tomorrow. I was going to pull a pump anyway so if I get one it's yours. Probably be like $5 bucks then $5 for me driving to the Post Office then shipping. Unless you feel that's too steep a price?. :P

Re: Fuel pump dead?

Posted: March 30th, 2011, 6:58 pm
by _lithium_
Haha that'd be a great price, as long as it works.

Just a question though: If my Fuel pump was going out, wouldn't it just either work or die, no in between?

My car started and is working, but is SUPER hard to get started, it takes about a minute of cranking for it to actually start. Also, when I drive it is extremely rough driving

Re: Fuel pump dead?

Posted: March 30th, 2011, 9:05 pm
by Daninski
Once you check for fuel its good possibly the coil/disty next. You do have a spare disty don't you or do I have to grab one of those two. :P Unless the weather turns ugly I'll be going to the yard tomorrow in the am.

Re: Fuel pump dead?

Posted: March 30th, 2011, 9:58 pm
by _lithium_
I don't think it'll be the disty, my brother that owned the car previously had replaced it twice. I'm going to try and test the pressure here in the next day or two whenever I get time but I am actually hoping it is the fuel pump.

Re: Fuel pump dead?

Posted: March 31st, 2011, 10:32 am
by Daninski
i'd start spraying penetrant on the fuel pump screws now, they can be very difficult to remove without breaking them off. Tapping and drilling out screws on an open fuel tank is not my idea of a good time.

Re: Fuel pump dead?

Posted: March 31st, 2011, 1:10 pm
by davmac
lithium your symptoms really sound more ignition related than fuel related. Still not a bad idea to check your fuel pump to eliminate it from the mix. You jumper the F/P and GND terminals under the diagnostic box and the fuel pump will run with the ignition switch turned to the on position. Installing a fuel pressure gauge and measuring max pressure can be found here and other fuel pump tests in adjacent pages in the manual.

Keep in mind that before you disconnect any fuel hoses to connect your gauge or to replace the fuel sender you should disconnect the fuel pump electrical connector under the rear seat while the car is running and wait for it to stall and them open the tank by removing the gas cap.

Re: Fuel pump dead?

Posted: March 31st, 2011, 1:54 pm
by Daninski
I went to the pic n pull today and sorry, no fuel pump. The gas tank was removed and the pump assembly was laying in the trunk buried under a pile of junk. All the other MX's he had are crushed. :(

Re: Fuel pump dead?

Posted: March 31st, 2011, 5:31 pm
by _lithium_
Well it is getting worse (or seems like it) Just for the hell it here is a symptoms list: (and Dan, thanks for trying though!)

- When idling at a light, the idle is rough (bounce between 700RPM and 1100RPM)
- In first gear, take off is EXTREMELY rough, car jolts back and forth and fights to stay on and not stall.
- When on interstate, going 60MPH and trying to floor the gas pedal, the car accelerates but you can feel it jolting (not very rough but noticable and you can see a small jump in RPM's).
- While sitting in the parking lot without the clutch down or anything and car idling, sometimes it will fall in RPM's so low that it stalls.

- I've had problems with my coolant not pulling out of the reservoir at all (and in fact, it is all the way to the top cap of the reservoir) and i have to put in coolant every 4 days or so with about 1/6 of a bottle of coolant in the Filler cap. (I found a leak under the other cap that is near the Intake. This cap sits on a plastic housing that is screwed onto the plastic thing of the Radiator.)

Also, I have http://shop.advanceautoparts.com/webapp ... 2020A_____ this for a fuel pressure gauge and that page that you mentioned above, would this gauge fit that manual? I don't see any port on my Mazda that looks like that and have heard i have to take out the fuel filter and put a line on each side.

Re: Fuel pump dead?

Posted: March 31st, 2011, 8:35 pm
by _lithium_
OK.... new problem that actually solved the past one...WTF!



Me and my brother were messing with it once it wouldn't turn on, it just kept cranking but no start. He pulled the spark plug wire on the front left (when you are looking directly down at it) and the car turned on and still felt normal rough idle and rough feeling, he gently just laid the plug wire into the socket where you can hear it sparking the spark plug and wah lah, the car runs smooth again, then if you press the wire into the socket to where it is where it is supposed to be (pressed into the socket and where they are made to sit) the car dies almost immediately, WTF...I can't figure out why in the hell this would happen???


::EDIT:: and I was able to drive it home while it sounded and felt absolutely normal (except a few misses that i expected since the plug wire is practically loose in the socket). But when I get home and press the wire to where it sucks onto the spark plug and is depressed down, it dies...

Re: Fuel pump dead?

Posted: March 31st, 2011, 8:56 pm
by Ryan
could be cracked plug insulation or bad lead. Both happen often enough.

Your cap may also be bleeding spark between leads, try replacing that