Of using a jumper wire in the GND and F/P terminals to prime the fuel system, if turning the key to the "ON" position does the same thing. Atleast that is what I was gathering from reading other posts.

Does a guy have to jump the two on the diagnos box or is turning the key to the "ON" position (obviously without starting it) accompish the same thing?

Oh, and if you do have to jumper the two, which ground do you use or does it matter. I noticed there are two grounds in the diagnostic box.

 

good question, I know some cars wont prime until the computer actually sees air going into the engine, and why are you priming? the fuel system should hold residual pressure from the last time you shut it off.

 

Because last time I shut it off was almost 2 years ago, and that was a different motor. Just going over the last details, and I'm a little scared to jump the fuel pump through the diagnostics box because 2 days ago when i did it, my starter connections started to smoke.

Granted, that had absolutely nothing to do with me putting a jumper wire in and was a pre-existing time bomb waiting to go off because the boot had a hole in it and bare wire was able to touch the metal sleeve on the starter solenoid, but still makes a guy nervous. Shrink tube to the rescue.

Thats why I wanted to know if I just turn the key to "on", if it will do the same thing.


If it helps, I have a power fc.

 

In the case of the 93 that I have, the pump will not run just by turning on the key. Once the key was turned into the start the position, even for just a second, the pump would begin to run and would run for about 4 to 6 seconds.

 

My fuel pump runs in the ON position. Maybe mine is rewired from a previous owner, or maybe they're all like that.

 

Using the jumper method keeps the pump constantly running while ground and FP are jumped, conversely keeping the key in acc/on, will activate the pump only briefly. I can sit in my FD with the key in the 'on' position and watch my fuel pressure stay at 1-2 bar, then slowly bleed off as I sit there. I have the Apexi BNR pump and I can hear it activate for about 1 second or so, but that's it---this with the key in the 'on' position.

 

^Same. When I turn my key on (without starting the car) my fuel pump turns on and pressure jumps to full PSI, where it will hold for maybe a second, then it drops about 5 psi. It will hold there for a moment more than drop slowly but steadily. I've never sat there long enough (and paid attention) to see how low the fuel pressure drops before starting my car.

I would only bother jumping the pump if you have a FPR which you're trying to adjust, and need a constant reading to make sure you've got the pressure right.

 

......or if you just installed a fuel system and/or motor and want to check for leaks before firing her up

 

Good point. I should change my description to say "Still a newb at heart"

 

No leaks in either fuel or coolant. just need to pull the egi fuse and build some oil pressure and check all those areas for leaks, and fire her up. I was going to do it tonight, but at the time I was ready it was almost 11pm and I didn't want to upset the neighbors, even though if it did start they'd probably be happy for me because they've all seen it in the garage for the past 2 years, but this gives me a chance to look things over and say a prayer.

 

Good luck!!! Let us know how she goes =)

 

it didn't go well. I don't think I'm getting spark, but I know I am getting fuel.

this is getting to the point of surpassing frustration........