Sai Li Fuel sysem and dropping rail pressure (2018)--Log attached

[gimmie11s]

Im in the middle of tuning my 2018 car with twin turbos and noticing rail pressure dropping to 35 psi or less under low boost. Has anyone else had this issue? Tuner thinks one pump might not be working but the install of this system is pretty straight forward and I don't see how I could have fumbled this up during the install.

Any ideas guys?

I tried to attach a log but it wont let me upload a .csv?

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[3beeps]

You can use this site to upload the log for us: https://datazap.me/

I have that fuel system for my 2017 and I had one of the fuel pumps die in under 2000 miles. He replaced it for me but it could have caused catastrophic damage since the car runs fine on one pump until full boost.

 

[gimmie11s]

I verified both pumps are running. I pulled one fuse at a time out of the pump harness with my ear next to the pumps and verified both are working. I also got a drop in fuel pressure at the regulator after pulling a fuse.

Here is the log.. thanks for the datazap.me info.

https://datazap.me/u/gimmie11s/log-1547846617?log=0&data=1

 

[drumstick]

Are you with Lund?

 

[gimmie11s]

Are you with Lund?

Yep.

 

[Tommy V]

Take a volt meter and put it in the dc volt scale.Check u grounds and make sure u dont have anymore then 0.01 volts going through your ground.I used the ground at the fpm and had .05 volts running through my ground.Pumps went lean before 6k rpm.Also check battery voltage and make sure u dont have serious voltage drop across your postive wire at your pump.

 

[gimmie11s]

Take a volt meter and put it in the dc volt scale.Check u grounds and make sure u dont have anymore then 0.01 volts going through your ground.I used the ground at the fpm and had .05 volts running through my ground.Pumps went lean before 6k rpm.Also check battery voltage and make sure u dont have serious voltage drop across your postive wire at your pump.

This will be a good exercise. Thank you and will do.

 

[Tommy V]

This will be a good exercise. Thank you and will do.

If u need any other help pm me,i went through the same thing with my setup.

 

[SolarFlare]

Buddy of mine went thru this with his Paxton, Boss manifold S197. Tons of tweaks and troubleshooting later he dropped the kit for a Fore dual pump system, perfect ever since.

 

[gimmie11s]

Buddy of mine went thru this with his Paxton, Boss manifold S197. Tons of tweaks and troubleshooting later he dropped the kit for a Fore dual pump system, perfect ever since.

Yeah, that’s the obvious answer. I am going to invest the sweat equity and make this one work.

No reason it doesn’t support the power it’s quoted as being able to support.

Probably going to upgrade my rails too. There are 2 “rails” on the 18+ cars. The rail connected to the fuel pump feed goes directly to the high pressure pump.

The rail the port injectors are connected to is fed by that high pressure rail with a super tiny single feed off the top rail.

I think this might be why the system can’t maintain higher pressure on the port rail.

 

[Tommy V]

90% of the problems i see guys have with this system is in the wiring!!!

 

[10r80]

I’m installing the kit (with rails) on my 18 right now as well-

Just got the fuel hat in and ran the lines to the engine bay for far

 

[Mustanggt5.02011]

You can use this site to upload the log for us: https://datazap.me/

I have that fuel system for my 2017 and I had one of the fuel pumps die in under 2000 miles. He replaced it for me but it could have caused catastrophic damage since the car runs fine on one pump until full boost.

Nothing against that fuel system by any means but that is exactly why I would never have a multi pump system run my car. You could be racing under heavy load and have one pump give out. You won't know until its to late. It happens.

 

[SolarFlare]

Nothing against that fuel system by any means but that is exactly why I would never have a multi pump system run my car. You could be racing under heavy load and have one pump give out. You won't know until its to late. It happens.

So you would never run a return system in a mustang?

 

[gimmie11s]

I’m installing the kit (with rails) on my 18 right now as well-

Just got the fuel hat in and ran the lines to the engine bay for far

Definitely report back on your port rail pressure under boost!

I’m sure the rails are gonna clean up my issues (hopefully).

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