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Long story short, dropped a new fuel pump into my car today, turned the key to ON, not hearing it prime. Car cranks and cranks but wont start. Checked all the fuses, plugs have less than 15k on them, gutted cat for about a year now, new coiles and wires. Cleaned the MAF.
Jumpering the two pins sticking out in the fusebox does nothing either, don't even hear the pump kick on. I'm getting juice at the plug on the wire harness that plugs into the fuel pump assembly. So far I am at a loss. Is there anything else that could be interfering with this pump turning on? Maybe something I'm missing?
If electricity is getting to the pump and it ain't pumping then you need to put the old pump back. Its either DOA or you messed up the install somewhere.
you are missing the obvious. Please see the schematic I edit-added to the prior post.
I did check the resistor. However i'm not sure if this harbor freight multimeter is just screwed, or if i'm doing something wrong. Pics Below.
The Mazda service manual says the resister should read between 0.304-0.336 ohms. the reading I am getting when I check the two terminals on the resistor is on the display. What confuses me is, the manual for the multimeter says i should be getting 0 when I short the test leads together, and i'm not. So I don't know if the reading I get when I test the terminals is accurate as well.
Heres my reading i got when measuring the terminals on the resistor.
Leads in the terminal:
Electrical is not my expertise, but I hope someone can chime in if they have any insight as to if im doing something wrong, if my multimeter is set wrong or just not measuring right, or if the resistor is actually bad.
You just have one of the cheapest multimeters in the world. (Those are at Harbor Freight and places for a whopping $1.00 here) Massive errors are expected.
When in doubt borrow one from someone (or spend the $30 and get a pretty good one that will last forever). The Innova brand is good, I wouldn't recommend flukes or anything like that unless you're going to do really complicated or accurate stuff.
That multimeter is only accurate at high impedances. And I am using the term "accurate" very loosely here.
Find another multimeter that has a "20" setting on it, as it will read out to two decimal places. It is much more difficult to read small impedance values than compared to large values.
You just have one of the cheapest multimeters in the world. (Those are at Harbor Freight and places for a whopping $1.00 here) Massive errors are expected.
When in doubt borrow one from someone (or spend the $30 and get a pretty good one that will last forever). The Innova brand is good, I wouldn't recommend flukes or anything like that unless you're going to do really complicated or accurate stuff.
I found the Innova brand in stock at Autozone, going to pick it up today.
That multimeter is only accurate at high impedances. And I am using the term "accurate" very loosely here.
Find another multimeter that has a "20" setting on it, as it will read out to two decimal places. It is much more difficult to read small impedance values than compared to large values.
Think the one I linked in my previous post will be sufficient?
That is a nice unit. You should be able to get a decent on at Home Depot, etc. I have a nice Klein multimeter and I got it at Lowes (not sure where you are from). Fluke brand meters are nice as well.
Well something doesn't make sense here. If you have voltage at the pump (and a good ground), and the pump works then it should pump when voltage is applied then it should be pumping.
Either the pump is pumping and you aren't hearing it, or there isn't power to it. Please recheck the power at the pump.
Think the one I linked in my previous post will be sufficient?
Anything is better than the one you currently have. I have no experience with the one you linked though, so not sure.
Have you checked to make sure that the wire terminal ends are seated properly in the harness plug? I have had experiences with the metal clips sliding out of the plug and not making contact with the pins. You will see voltage if using a multimeter though since you will stick the probes into the plug end and reach the terminal ends.
Anything is better than the one you currently have. I have no experience with the one you linked though, so not sure.
Have you checked to make sure that the wire terminal ends are seated properly in the harness plug? I have had experiences with the metal clips sliding out of the plug and not making contact with the pins. You will see voltage if using a multimeter though since you will stick the probes into the plug end and reach the terminal ends.
Oookay, went with the Innova multimeter from Autozone.
Touching the two leads together, this one actually reads zero like it should.
However, when I measure the resistor, here are my readings.
I've seen it fluctuate from as low as .5 to as high as .7 if I move my hands a bit,
Factory service manual says it should read 0.304-0.336 ohms
Would I be correct in assuming this resistor needs to be replaced and may be the culprit? And if thats the case, would someone be kind enough to post that part number?
It may or may not be safe to say that. I think that's probably the issue.
Before you do that, if you want to confirm it, I would recommend powering the high pressure relay coil so that it skips the resistor altogether. If it still doesn't work after that then you can rule out a bad resistor.
The part number is 056777-0770 from Denso. I think they're kind of expensive, but an aftermarket one of similar resistance or one from a part out would be sufficient. They don't fail often.
It may or may not be safe to say that. I think that's probably the issue.
Before you do that, if you want to confirm it, I would recommend powering the high pressure relay coil so that it skips the resistor altogether. If it still doesn't work after that then you can rule out a bad resistor.
The part number is 056777-0770 from Denso. I think they're kind of expensive, but an aftermarket one of similar resistance or one from a part out would be sufficient. They don't fail often.
How would I go about powering the high pressure relay coil? Or at least finding the instructions on how to do so?
Edit: are you sure thats the part number? I mean, thats whats written on mine as well, but when I try and search by part number via onlinemazdaparts, nothing comes up.
I think this has turned into a wild goose chase. Reading less than an ohm on a multimeter accurately is a little tricky so I doubt its the fuel pump resistor. The fuel pump only runs for a second to prime when the ignition turns on (in high speed) and again while cranking (I believe that is in slow speed.) Even if the resistor was bad you would still have the engine sputter and die while cranking.
The options left are either the pump, the wiring/connections or the ecu. Use the jumper in the fuse box to force power to the pump then check for pump noise or voltage at the pump. this problem is not that complicated.
I think this has turned into a wild goose chase. Reading less than an ohm on a multimeter accurately is a little tricky so I doubt its the fuel pump resistor. The fuel pump only runs for a second to prime when the ignition turns on (in high speed) and again while cranking (I believe that is in slow speed.) Even if the resistor was bad you would still have the engine sputter and die while cranking.
The options left are either the pump, the wiring/connections or the ecu. Use the jumper in the fuse box to force power to the pump then check for pump noise or voltage at the pump. this problem is not that complicated.
I've already tried the jumper. with the OEM pump in, and this Delphi. It doesnt do anything.
I've already tried the jumper. with the OEM pump in, and this Delphi. It doesnt do anything.
I saw that, but were you checking voltage at the pump? Did you have two people so one person could listen for the pump turning on? Could you hear the pump turn on before you did anything to it? And the big question. Was it running fine before you replaced the pump?
If all the facts in this thread are correct then the pump should work and the car should start. Obviously we've missed something.
I saw that, but were you checking voltage at the pump? Did you have two people so one person could listen for the pump turning on? Could you hear the pump turn on before you did anything to it? And the big question. Was it running fine before you replaced the pump?
If all the facts in this thread are correct then the pump should work and the car should start. Obviously we've missed something.
I am getting voltage at the connector that plugs into the pump assembly.
Had my girlfriend turn the key to on with my ear on the fuel pump cover, no noise.
The original pump wasn't priming, neither is this one.
And no it wasn't running fine, car died getting on the highway, had no throttle response, pulled over, barely idling, shut it off, Car hasn't started since.
04-01-2015, 12:14 PM
