Fuel pump harness

[ninjadave]

Hey everyone, so I'm trying to start my build for the first time and It won't crank and I don't hear my fuel pump coming on. I did the rewire kit and know everything is hooked up correctly I triple checked. I'm getting 12v to the relay from the battery but there's no voltage going to the relay from the harness that originally connected to the pigtail that attaches to the fuel pump assembly. Do I need to check my mpi fuse also even though I rewire my fuel pump? The no crank is next to diagnose after the fuel. Thanks guys.

 

[Talyn]

Fuel pump doesn't come on with ign power, it comes on when you crank the engine(Only car I've ever owned that does that), so its very possible the two problems are related. That said, there is a jumper wire on the firewall that will allow you to test operation of the pump.

 

[kenamond]

Not much to add here. You can apply 12v directly at the pump relay and see if the pump activates. If not, either the relay or pump is bad. I imagine there's a way to hotwire the pump and bypass the relay, but I know not how to do this.

As Talyn already mentioned, the pump doesn't come on unless (IIRC) the cam position sensor (CPS) detects engine rotation. Turning the key to "on" doesn't fire the fuel pump, so don't let that derail your diagnosis...the engine has to be rotating for the pump to actuate, so any problem that keeps the motor from rotating (dead starter as an example) will keep the fuel pump from activating.

In theory, it could be the CPS. In reply mode, I can't see your profile, but if you have a 2gb, it's easy-peasy to change the CPS...one 10mm bolt on the passenger side of the valve cover on the intake cam end...and a sensor plug, but it's a bit expensive - $80 when I did mine about 5 yrs back. If you have a 2ga, it's a PITA (CPS is "securely nestled" amongst the timing belt and pulleys on the front of the motor, I believe also on the intake cam end). No clue about the 1gs, but I vaguely recall that they're more like the 2gb. No clue on 2ga or 1g CPS cost.

Bottom line: until you get the motor to turn over, don't look at fuel as the cause.

 

[poteau]

Should be paying more attention to the starter relay which is under the steering column (I believe, at least it's there on the EVO) that relay should be clicking to apply the ground signal to the starter to cause it to crank.

 

[ninjadave]

Thanks for all the replies everyone. Yeah I did a bunch of testing and found that it was a starter issue. I was always use to the fuel pump priming itself so not hearing that initial "hum" kinda worried me. I did notice it activates with the motor turning over so I'm content with the pump now. Yeah I'll take a look at that cps sensor and see of it's damaged or anything at all. Thanks guys