Fuel Problem
 

I cant seem to get fuel pressure to the engine or even hear the damn pump come on. I ran a few tests but need some input on if the voltage im getting to the fuel pump is correct.

I disconnected the fuel pump and attached my meter to that connector, turned the ignition on and jumped the FP and GND terminals and I get 2.93 on the voltage meter and I also hear the Circuit Control Relay making a noise at the same time. But when I jump the terminals and get the 2.93 on the meter it only last for a second and than counts down to zero. Is this normal for it to do this? If this normal than tomorrow I will folow your steps in pulling out the pump and checking/test it.

If this voltage is fine should I assume the pump is the issue? BTW the car is in stock form with no fuel mods.

Anything else I should be looking for?

Anyone?

All I need to know is if the voltage going to the pump is correct and if it should be dropping like that. This will tell me if maybe I should be looking at the fuel pump or somewhere else.


Thanks

You should have battery voltage at the connector.

You might want to check you relay and resistor.

Easiest way to check your relay is to swap it with a known good.

The resistor, located under your master cylinder, can be checked by measuring the resistance with a ohmmeter.(.57 - .70 Ohms is spec.)

So even though I can see the relay close, it can still be bad? What sucks is that there arent any Mazda dealers near me. Is there any relay under the hood that can be swapped to test?

just to be sure what reading do you get when you put the test leads on the poss and neg battery terminals? making sure the meter is working and in the right range

I will check that soon as I get home from work. Also should the volts drop like that? When I jump the two terminals the meter goes up to the 2.93v even if on the wrong setting is it normal for it to drop down to zero within 3 seconds?

I'm pretty sure the meter is on the right setting but again I will double check by testing the battery voltage.

What would limit the amount of voltage going to the fuel pump?

Just a heads up the car has been sitting and not started for up to 5 years. I flushed the fluids and changed the plugs and she started right up and Idled perfect that whole day. When I test drove it up the street when accelerating in first gear it would take off well than suddenly feel like the motor stalled and lost power but once It would get down to the lower RPM I would have to go leasy on the peddle to drive it. I thought the pump wasnt feeding enough fuel but when I parked it I was able to rev it with no problems. Could it be a grounding issue maybe from the car sitting?

Thats what it turned out to be with the meter reading 2.93..... Thanks mad_7tist... I thought I had another problem somewhere else, I feel stupid now.

I'm going to pull the pump out this weekend (its too dark when I get home from work) and see whats going on.

Should I replace it with the OEM pump or go with an aftermarket or even the Supra one?

ok so you have a weak/dead battery or a incorrectly set/fubared meter. charge the battery. make sure you are on dc voltage. as for the pump alot depends on your future plans. supra pump is a solid nice toyota stocker. good reliability.

Have you changed your fuel filter recently?

Get yourself a shop manual. The pump only runs constantly with the engine running. When you turn the key it pulses on for a second to charge the fuel line. Low voltage is correct, the resistor mentioned feeds low voltage to the pump when there's low load.

On the diagnostic plug, you can jump 10 (not positive on this number) and GND to run the fuel pump w/o the engine running. Using this method, the workshop manual has a few tests to run.

The Supra pump is ok for moderate mods. I used one for a couple of years but it died not long after I started running constant 13V.

Jack