Jump to content

Recommended Posts

I have a 2000 626 V6 m-trans with 157K miles.

Grey626 ... thanks for the time-saving thread below and the helpful pics!

http://mazda626.net/...it/#entry337545

I've learned a lot on this forum from thoughtful contributors such as Snailman and NickR (and others) ... and I really appreciate contributors who take time to post helpul info like you've done here. If I end up having to replace the fuel pump, it your post will be a big help.

Now to my problem. My car failed to start at the gas station after refueling. No prior warning ... it was running fine and had 1/4 tank of fuel when I stopped to add a few additional gallons. When it failed to start after adding fuel, I suspected contamination in the fuel I had just added. However, there were many other cars there refueling from the same set of pumps without problems ... plus, the owner of the station was there and immediately pumped some into a clear glass jar to check it (no obvious contamination indicated).

I had the car towed to my house and have been working on it since. The engine cranks fine and has good spark but won't start (although it occasionally seems to "try" to start). Based on what I've read in this forum, the failure to start is probably due either to (a) bad fuel pump, or (b) bad crankshaft position sensor.

The crankshaft position sensor measures correct resistance on the ohm-meter so I assume it's OK (per test in Haynes manual). However, I can't seem to get fuel to the engine. The diagnostic procedure in the Haynes manual is a little vague but seems to be leading me to the fuel pump. Here's what I've done so far.

1. replaced fuel filter

2. checked fuel system ("EGI") fuse

3. checked EGI relay

4. have assistant turn ignition on so I can listen at fuel tank filler neck for 1-2 seconds of fuel pump noise indicating pump is working (no noise)

5. remove EGI relay and try to turn the pump on manually by jumper wire from the "30" terminal to ground. I assume ignition is supposed to be on and the relay isn't supposed to be plugged in while conducting this test. Anyway, I don't hear the fuel pump running, even with jumper wire in place.

6. checked for power at fuel pump connector at top rear of fuel tank when assistant turns igntion on (no power). It's this test that leads me to doubt my conclusion that fuel pump has failed; based on my understanding of the way the fuel system is supposed to work, I think I should have 1-2 seconds of power at this connector when ignition is switched on.

Here are my questions.

1. Is there something else I should check before replacing the pump?

2. My fuel tank registers 1/2 full, which means it has apprx 65 lbs worth of fuel in it. If fuel pump needs replaced, how can I drain it the tank?. There's no drain plug. I've seen a post elsewhere in the forum where Mityvac through filler neck is recommended bu I'm unable to pass even a tiny hose through the filler neck into the tank so I assume it has an anti-siphon device of some sort that will keep the Mityvac (or any other kind of siphon) from working. The rear end of the car is jacked high on jackstands, so I think I can replace the fuel pump without fully removing the tank (as shown in the link pasted above) but I don't want to release the tank straps and struggle with the tank without emptying it.

Can any forum member advise? Thanks!!

Link to post
Share on other sites

It wouldn't be the crank shaft position sensor due To the fact that once the crankshaft hits a certain degree of revolution the cps( crankshaft position sensor) tells tells the computer system when to fire the spark plugs and also when to inject fuel into the cylinders via fuel injectors, therefore getting no fuel or spark. Get a voltmeter and test for voltage all the way down to the fuel pump to make sure you are getting power, I have had times where power was getting cut off at the fuel sending unit due to a bad circuit.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...