fuel pump question

[SupraBro]

so i went to start my car for the first time today after my build and no luck:3d_frown:.......everything seems good but no fuel. this is my first time cranking the car, the guy i bought it from drove it home and parked it for like 3 years because of a blown h/g....so i turn the key on and you dont hear the fuel pump at all....im not a noob whean it comes to wires so i got my meter and started checking things...i notice that there is no 12v going to the fuel pump relay....so i went from the batt strait to the rear of the car to the fuel pump with a 15amp and it just sparks and pops fuse...so i guess my question is if the fuel pump is broke or locked up is that normal?...and is there something before the relay that sences the fuel pump is bad and stops sending 12v to the relay...all fueses are good...put my fluke on ohm's and the all read great...just wanting to make shure something else is not messed up because that relay is not getting 12v...thanks for taking the time to read this, need help!!

 

[supradjza80]

Don't quote me but I am pretty sure that unless you are cranking the car the fuel pump does not receive power. To send power to the pump you need the key in the ON position and need to jumper Fp and +B terminals in the diagnostic block. See if you pump gets power by doing this.

 

[SupraBro]

well i went strait to the fuel pump with 12v....it just pops my fuse...so im shure my pump is out...but my question is since that relay is not getting power is something else out as well??....does something go in protect???..does the relay only get 12v during crank and not with just the key to the on position??....^^^^thanks for your help!!!

 

[supraguy@aol]

I believe that the relay will get power during cranking and for a second or two after. But if the car does not start, the power to the pump drops off.(JetJock can tell you for sure)
I would say that if you're sure the current pump is bad (which it does sound like), replace it, then see if all trouble had been resolved.
PS- If you're replacing the pump you'll want to upgrade to a MK 4 pump or Walbro- in the interest of future upgrades.
: )

 

[jetjock]

Listen to these guys, they know of what they speak. On a GTE the pump doesn't run until the key is turned to start. It's done by the starting coil in the dual coil Circuit Opening Relay. If the engine starts the pump will continue to run. That's done by the running coil in the COR which is energized by the ECU after it's satisfied the engine started. It's all in the schematic, which is usually the first place those who're are not noobs when it comes to wires look when they have a problem...

 

[SupraBro]

Guys....thanks for you help....you answerd all of my questions...what I was doing was turning the key on and trying to see 12v at the relay....my fail...and yes I'm doing the fuel pump upgrade...again thanks for your help!!!

---------- Post added at 11:25 AM ---------- Previous post was at 11:13 AM ----------

Jetjock....I guess since I'm mecp certified, and I do remote starts and alarms for a living I think I'm not a noob...lol...and your right...I should have done my search a little harder instead of just posting up...but thanks for your help...I respect your skills!

 

[89supra7mgte]

I would imagine that after sitting for 3 years the gas went bad which i have seen cause fuel pumps to short out and what not, might be the reason why you blow the fuse, or you are hooking it to the wrong wire? And unless you did the "mod" the fuel pump does not recieve 12v, i think it is around 10 or so due to the fuel pump resistor. Not sure if the resistor is before or after the relay, just for futrue reference, if you check voltages and see that.