- Joined
- Mar 22, 2017
- Messages
- 285
stock fuel rails? 800rwhp is around the limit on those I read somewhere... or did you upgrade fuel rails with the rest of the system?
14 GT Paxton New P.B.
- Thread starter Gruca
- Start date
Fuel rails were upgraded to VMP. I ended up taking the fuel pumps out and tested them in a bucket of fuel. I noticed only one was turning on. I switched the plugs and then the one that wasn’t on before was on this time but not the one that worked originally. I went and checked the wiring and a wire was loose enough for me to pull it apart. I soldered those together and verified both pumps were running. Installed it all back in the car and drove it around to warm up. I did a WOT data log to 6,500. It’s now 5-13% lean from 2,000 all the way to 6,500. Both pumps are now on and it got way worse! What in the ****.
I’d really like to burn it to the ground, with me in it, right about now...
Sent from my iPhone using the svtperformance.com mobile app
- Joined
- Mar 22, 2017
- Messages
- 285
Sorry but none of your lean conditions make any since man! Wish I could be of more help.
Sent from my SM-G930P using Tapatalk
Sent from my SM-G930P using Tapatalk
Maybe the pumps are being maxed out? They might be running but maybe not at %100. But Im with TTUhouston, I dont know enough to of more help.
V.C
V.C
I dumped 5 gallons of E85 in the hole the fuel pump goes in before I installed the pumps back in. Then I went and datalogged and got the back STFTs. So I decided that I should fill the tank since maybe one side didn’t get any gas in due to where I dumped in the gas. All theory here...
I filled it up 3/4ths of the way and drove for a bit. Did some low rpm WOT pulls and they weren’t going straight to 10% lean. So I went a little higher, same deal. STFTs were staying close to 1.0. Did a pull to 7,500 and same thing. It did get to 1.05 at one point which I didn’t like.
Sent from my iPhone using svtperformance.com
I filled it up 3/4ths of the way and drove for a bit. Did some low rpm WOT pulls and they weren’t going straight to 10% lean. So I went a little higher, same deal. STFTs were staying close to 1.0. Did a pull to 7,500 and same thing. It did get to 1.05 at one point which I didn’t like.
Sent from my iPhone using svtperformance.com
Didn't you go with the rodeheaver fuel system? If so i would check voltage at both pumps, this system uses dual FPCMs if I remember correctly so i would check it pre and post FPCM and make sure you have the voltage you need. Try checking it with just key on and then key on WOT. It sounds like your pumps are staying on the low voltage setting and not getting the extra juice when you go WOT, hopefully its as simple as a bad FPCM or another loose wire.
Keep us updated were all pulling for you!
Keep us updated were all pulling for you!
I didn’t even think about the voltage. I’m going to check that tomorrow. Thanks man!
Sent from my iPhone using the svtperformance.com mobile app
That is why I like this site. Collective thoughts to try and solve an issue. Good luck.
I was testing the fuel pump wiring harness for resistance from the ground to the battery (negative side) and found that the pin in the wiring harness would push out when pressure was applied. So I watched the wire as I plugged it in to the fuel pump and sure enough, the wire would move out of the connector as the male end moved into it. I tried everything to get that pin to stay in the connector but failed. $60 for a new one 
Sent from my iPhone using svtperformance.com
Sent from my iPhone using svtperformance.com
I was testing the fuel pump wiring harness for resistance from the ground to the battery (negative side) and found that the pin in the wiring harness would push out when pressure was applied. So I watched the wire as I plugged it in to the fuel pump and sure enough, the wire would move out of the connector as the male end moved into it. I tried everything to get that pin to stay in the connector but failed. $60 for a new one
Sent from my iPhone using svtperformance.com
At least you found that before killing the new motor!
After fixing the multitude of issues my fuel system had, I found one more. I was testing the pumps by unplugging the FPCMs, one at a time, while the car was on to see if it would die. I noticed when trying to unplug one that the ground wire was sparking where it connected to the car. The nut for it was loose. I tightened that down and went for a ride.
All of the logs came back good, consistently. I THINK I’ve finally fixed all the issues....hopefully....
Sent from my iPhone using svtperformance.com
All of the logs came back good, consistently. I THINK I’ve finally fixed all the issues....hopefully....
Sent from my iPhone using svtperformance.com
Last edited:
dude the shit is nuts ..i am around 6 months into boost and i am finally getting some reliability finally from all the ****ing mistkaes the shop made i had to correct last 6 months .... but once its sorted it will be worth it so u gotta keep going
I’m still having fueling issues. I took the fuel pressure regulator apart and noticed the 3 o-rings were eaten up (probably from over tightening them). I replaced those and I’m still not getting the correct 1:1 increase in fuel pressure while in boost. I still need to check the pump voltage at WOT to see if it increases. It’s 14.85v while idling. After that, the only thing left I can think of is the pumps themselves. If they worked correctly, they should be able to supply enough fuel for my setup. I’m getting the injectors cleaned out tomorrow just to rule it out, even though I don’t think they would cause my issues.
Both from earlier today. This shit is driving me crazy...
4th gear WOT pull:
3rd gear WOT pull:
4th gear WOT pull:
3rd gear WOT pull:
I tested both my FPCMs’ voltage and at partial throttle they are around 14.3 and at WOT voltage drops to 13.8...
I did the test at each plug that goes into the FPCM. Now to figure out what’s causing the issue.
- Joined
- Mar 22, 2017
- Messages
- 285
Have you called rodeheaver yet? They may know just by symptoms if they are as good as fore innovations was with my problems.
Isn't that a non-return system that needs a voltage increase at WOT? Like a boost a pump?
Users who are viewing this thread
