No power to Fuel Pump!

[1badtsiawd]

Hello everyone,

I had a post going on this awhile back and i still have the same issue. I have no power to my fuel pump. I put direct power to it and the pump kicked on. I changed the ecu and the mpi relay and nothing changed. My personal feeling is that it has to do with the mpi relay. It seems to be getting power into it just not coming out of it. I tested it and got the same numbers on both of the mpi relays i have. now this makes me want to buy another relay, but at the same time they are not cheap new and i really don't want to buy another used one and risk getting a bad one.

If anyone has any experience with these relays or knows what the test results should be on them, i would appreciate the help. The only test numbers i have to go off of are my own and they both turned up the same. Also if there is something else that could be the culprit please let me know.

thank you
patrick

 

[97 4G63]

Why not just do a fuel pump rewire??
take a look under fuel..
http://vfaq.com/index-main.html

 

[tbonitz301]

+1 on the rewire.

 

[1badtsiawd]

i already did the fuel pump rewire mod, with that you still have the power coming from from the mpi relay to kick on the relay you put in for the rewire mod. You could bypass the mpi all together i suppose and put in a switch to manually turn on and off the fuel pump. This to me is only bypassing the real problem though and i would not want to have to flip a switch every time i get in the car.

 

[kenamond]

The fuel pump doesn't turn on until you start the car. It doesn't turn on if you just go to the "on" position. Maybe that's not your problem, but I thought it was worth mentioning.

 

[1badtsiawd]

My fuel pump has always primed when i turn it to the run position. Further more when i crank over the engine and then check to see if there is any signs of gas at the injectors, i get nothing. I have a upgraded fuel pump so i could always hear it before.

 

[steve]

My fuel pump has always primed when i turn it to the run position.

But it's not designed to. The only things that turn on the fuel pump on a 1G are the starter circuit and the ECU when it sees CAS pulses. It seems that a few cars out there glitch the CAS signals when they turn on and that triggers the ECU but it's not by design to work that way.

What exactly are you looking for in this thread that you weren't provided in your prior thread on this subject?

http://www.dsmtuners.com/forums/problem-diagnosis/283361-please-help-me-fuel-problem.html

 

[1badtsiawd]

Well my car has always primed the fuel pump so that is all i am used too. If thats not how it is supposed to work that is fine, but i still don't have any power to the pump when i am turning the engine over.

Further more i am looking for something else that may be the problem that was not given in the previous thread. I'm not saying that thread was not a help but it also did not solve my problem, so i am looking for more input on the matter. There is one thing i would like to know, if anyone happens to know the answer. When you test the resistance between the coils on the mpi relay, what are the numbers supposed to be? I can't seem to find a answer to that anywhere.

 

[92awddsm]

Did you fuse the power wire when you did the rewire? If so, have you checked the fuse?

 

[1badtsiawd]

yes i did put a fuse in the rewire and i did check that. It's okay

thanks

 

[steve]

I'm not saying that thread was not a help but it also did not solve my problem, so i am looking for more input on the matter. There is one thing i would like to know, if anyone happens to know the answer. When you test the resistance between the coils on the mpi relay, what are the numbers supposed to be?

It's up to you to solve the problem, all we can do is provide some help.

I pulled the MPI relay out of my parts car and posted the measurements in the other thread.
Since there isn't any difference in the problem the two should be merged.

 

[92awddsm]

yes i did put a fuse in the rewire and i did check that. It's okay

thanks

Just making sure. Usually, the simplest things are overlooked.

 

[1badtsiawd]

Just making sure. Usually, the simplest things are overlooked.

Thats cool. Also these are the sort of things that i am wanting to make sure i did not over look because the simplest things are the easiest to overlook and may be causing me my problem.

It's up to you to solve the problem, all we can do is provide some help.

I know it is up to me to solve my own problem, and i thank everyone that has put in some input. I just have not been able to find the source of my problem and i have been racking my brain trying to figure it out and i am still looking for some help. I though maybe someone would have gone through this before and knew what it might be that i haven't thought of or checked yet.

thank you for posting the results from the mpi relay test.

 

[cody_miller_13]

i have the same problem put brand new relays in and still no power and hooked it up to the battery and it worked but wont start with it hooked up i still have not found the prblem but once i do i will let u know