No fuel pressure at damper.

Alphamythos · 10-27-2019, 05:25 PM

Appreciate any suggested guidance, first time posting.

Quick summary: car stalled on freeway. Wouldn't start , dealer said bad fuel pump. Bought CJ motorsports billet hat, and npt tap for front damper. Aem 340 pump.

Pulled fuel pump , test original pump with 12 volt source and it still worked. �� drilled ventri based on cj tech guide. Put all back together ran fine 100 miles then stalled again , no fuel pressure. Reading zero. When cranking reading zero and doesn't bump at all.

What I did : test ipdm , fuse has power both sides, fuel pump power supply getting power at terminal and power to relay as well. Checked power to hat getting power as when when cranking engine. Can hear pump prime and turn on during cranking.

Any suggestions on how to solve , can regulator in house be bad, car only at 50k. Should I just go to return fuel system ? Trying to avoid more cost, but would like to confirm or solve the issue. Thanks again for ideas

WhiskeyHotel · 10-28-2019, 07:48 AM

Speaking from experience, it's possible to hear the fuel pump prime with key on and still have a "fuel pump" problem, especially if you have had to modify the basket/venturi. I'm running a Stillen SC kit and had a similar issue - car just flat died cruising down the road. Crank, no start. Measured fuel pressure - nothing. Everything else checked out. Finally gave in and pulled the darn thing again.....and yeah, I had screwed up the modifications for the fuel pump. It took about 100 miles for it to catch up with me. Thankfully it was something that could be remedied without a new basket/filter.

Good luck!

Jayhovah · 10-28-2019, 09:23 AM

user phunk (CJM Motorsports) is the resident fueling expert and is generally amazingly helpful to forum users.

phunk · 10-28-2019, 03:37 PM

Did you plug-in the in-tank siphon hose when you reinstalled the fuel pump housing? This is one way I can think of that the car would run and then just not run seemingly for no reason.. unless something came apart in your fuel pump rebuild.

If the pump is turning on, and there is fuel beneath it to pump, the only way it wouldnt be getting to the engine is via a leak either internal to the fuel pump module or external in the fuel plumbing (which would be obvious via a puddle of fuel on the ground).

You will probably just have to diagnose it manually. Make sure there is fuel where the pump is (if not, siphon setup probably isnt connected or venturi not working), make sure the pump is turning on and pumping fuel (if not then bad pump or bad wiring), and then figure out where the fuel is going (if its leaking out then it will be easy to find where).

Alphamythos · 10-28-2019, 04:50 PM

Thanks Phunk I'll check the syphon tonight. I'm pretty meticulous when doing things but could have came lose or didnt fully connect when putting back on. And do a pressure test at the pump internal and hat external, and tank connection to be sure. There's no leaks anywhere externally.

Rusty · 10-28-2019, 11:21 PM

OP, you driving straight down the road, or did you make a right hand turn, when it died?

Jetsimple · 10-29-2019, 12:24 PM

Quote:

Originally Posted by WhiskeyHotel

I had screwed up the modifications for the fuel pump. It took about 100 miles for it to catch up with me. Thankfully it was something that could be remedied without a new basket/filter.

Good luck!

I’m interested in getting specifics on this screw up, as I just modified my pump and will be installing it back in the car today. I will also be running the Stillen SC soon.

10-27-2019, 05:25 PM	#1 (permalink)
Alphamythos Base Member Join Date: Feb 2017 Location: Arizona Posts: 2 Drives: 13 Nissan 370z Rep Power: 8	No fuel pressure at damper. Appreciate any suggested guidance, first time posting. Quick summary: car stalled on freeway. Wouldn't start , dealer said bad fuel pump. Bought CJ motorsports billet hat, and npt tap for front damper. Aem 340 pump. Pulled fuel pump , test original pump with 12 volt source and it still worked. �� drilled ventri based on cj tech guide. Put all back together ran fine 100 miles then stalled again , no fuel pressure. Reading zero. When cranking reading zero and doesn't bump at all. What I did : test ipdm , fuse has power both sides, fuel pump power supply getting power at terminal and power to relay as well. Checked power to hat getting power as when when cranking engine. Can hear pump prime and turn on during cranking. Any suggestions on how to solve , can regulator in house be bad, car only at 50k. Should I just go to return fuel system ? Trying to avoid more cost, but would like to confirm or solve the issue. Thanks again for ideas Last edited by Alphamythos; 10-27-2019 at 05:28 PM.

10-28-2019, 07:48 AM	#2 (permalink)
WhiskeyHotel Track Member Join Date: Nov 2009 Location: Oklahoma Posts: 530 Drives: 2015 GT-R PW Premium Rep Power: 17	Speaking from experience, it's possible to hear the fuel pump prime with key on and still have a "fuel pump" problem, especially if you have had to modify the basket/venturi. I'm running a Stillen SC kit and had a similar issue - car just flat died cruising down the road. Crank, no start. Measured fuel pressure - nothing. Everything else checked out. Finally gave in and pulled the darn thing again.....and yeah, I had screwed up the modifications for the fuel pump. It took about 100 miles for it to catch up with me. Thankfully it was something that could be remedied without a new basket/filter. Good luck! Last edited by WhiskeyHotel; 10-28-2019 at 07:52 AM.

10-28-2019, 03:37 PM	#4 (permalink)
phunk A True Z Fanatic Join Date: Mar 2009 Location: Chicago Posts: 3,668 Drives: 370 Rep Power: 974723	Did you plug-in the in-tank siphon hose when you reinstalled the fuel pump housing? This is one way I can think of that the car would run and then just not run seemingly for no reason.. unless something came apart in your fuel pump rebuild. If the pump is turning on, and there is fuel beneath it to pump, the only way it wouldnt be getting to the engine is via a leak either internal to the fuel pump module or external in the fuel plumbing (which would be obvious via a puddle of fuel on the ground). You will probably just have to diagnose it manually. Make sure there is fuel where the pump is (if not, siphon setup probably isnt connected or venturi not working), make sure the pump is turning on and pumping fuel (if not then bad pump or bad wiring), and then figure out where the fuel is going (if its leaking out then it will be easy to find where). __________________ Charles @ CJ Motorsports : Website \| Facebook \| Instagram \| YouTube Home of the 9 second, stock longblock, stock drivetrain 6MT 370z. 9.91 @ 142mph

10-28-2019, 11:21 PM	#6 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 68 Posts: 35,221 Drives: 2011 Nismo GM 6M Rep Power: 2684438	OP, you driving straight down the road, or did you make a right hand turn, when it died? __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

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10-28-2019, 04:50 PM	#5 (permalink)
Alphamythos Base Member Join Date: Feb 2017 Location: Arizona Posts: 2 Drives: 13 Nissan 370z Rep Power: 8	Thanks Phunk I'll check the syphon tonight. I'm pretty meticulous when doing things but could have came lose or didnt fully connect when putting back on. And do a pressure test at the pump internal and hat external, and tank connection to be sure. There's no leaks anywhere externally.