Bad fuel pressure regulator?

Jason99GSX · Aug 23, 2020

Hey guys having some fuel related issue and can’t seem to narrow it down. The car right now has FIC 2150s and a walbro 450. I was having an issue every time the turbo would start to spool as soon as I hit 5k I just get back firing and breaking up and it’s lean. At first I thought it was maybe just the anti lag turned on and activating. I turned it off via link and the issue remained. I was pretty positive then that maybe just the pump wasn’t holding pressure under WOT. So I drilled out the stock feed and installed a bulkhead fitting and I was pretty sure that would fix it. Still again this issue remains.... it seems like fuel pressure just isn’t rising when I’m getting into boost. Could maybe the regulator be bad? It has an aftermarket Fuel lab regulator. I can’t think of what else it could be. The regulator is about 6 years old. There is no fuel in the vac line. Any help would be great! Thanks in advance.

SasaniFab · Aug 23, 2020

Jason99GSX said:
Hey guys having some fuel related issue and can’t seem to narrow it down. The car right now has FIC 2150s and a walbro 450. I was having an issue every time the turbo would start to spool as soon as I hit 5k I just get back firing and breaking up and it’s lean. At first I thought it was maybe just the anti lag turned on and activating. I turned it off via link and the issue remained. I was pretty positive then that maybe just the pump wasn’t holding pressure under WOT. So I drilled out the stock feed and installed a bulkhead fitting and I was pretty sure that would fix it. Still again this issue remains.... it seems like fuel pressure just isn’t rising when I’m getting into boost. Could maybe the regulator be bad? It has an aftermarket Fuel lab regulator. I can’t think of what else it could be. The regulator is about 6 years old. There is no fuel in the vac line. Any help would be great! Thanks in advance.

You fuel are you running? e85? Does this happen at any boost level? Im assuming your fuel pump is rewired? The car is on stock fuel lines and return?

Jason99GSX · Aug 23, 2020

SasaniFab said:
You fuel are you running? e85? Does this happen at any boost level? Im assuming your fuel pump is rewired? The car is on stock fuel lines and return?

Car is on pump gas right now. Pump is rewired. And yup stock feed and return lines.

SasaniFab · Aug 23, 2020

I had a similar situation where 1 of my fuel pumps came disconnected , the car went lean at high boost but didn't break up. Ive also forgotten to connect the vacuum line to the fpr, car was lean but didn't break up. When you say lean ... what is lean

Jason99GSX · Aug 23, 2020

SasaniFab said:
I had a similar situation where 1 of my fuel pumps came disconnected , the car went lean at high boost but didn't break up. Ive also forgotten to connect the vacuum line to the fpr, car was lean but didn't break up. When you say lean ... what is lean

Hmm ok...and the gauge will go full sweep red. It’s the AEM digital gauge so you get the three dashes.

SasaniFab · Aug 23, 2020

Jason99GSX said:
Hmm ok...and the gauge will go full sweep red. It’s the AEM digital gauge so you get the three dashes.

Is this a wideband gauge? The aem wideband has a digital numbered gauge. The narrow band gauge has dashes ?

I should of asked from the get go , your running the car on fic 2150s on pump gas? These are the fic high z 2150s? First and foremost have you set them up correctly in ecmlink ? Your injector voltages, global and deadtime ?

rabenne · Aug 23, 2020

How do you know its lean? Anything but a wideband and it sounds like you are just guessing.

Are you also just guessing this is a fuel pressure issue? A fuel pressure sensor/gauge could rule all that out in a few minutes. Add a hand pump and you can test the regulator pressure vs "boost pressure".

Have you done a boost leak check? Did you fix all the leaks?

motomattx · Aug 24, 2020

A misfire of any kind even a rich misfire will show lean on a wideband from unused air, a wideband only measures oxygen content remember. You could very well have an ignition problem and be misunderstanding it as a fuel system problem.

Jason99GSX · Aug 24, 2020

SasaniFab said:
Is this a wideband gauge? The aem wideband has a digital numbered gauge. The narrow band gauge has dashes ?

I should of asked from the get go , your running the car on fic 2150s on pump gas? These are the fic high z 2150s? First and foremost have you set them up correctly in ecmlink ? Your injector voltages, global and deadtime ?

Yes it is a wideband gauge. And that wideband will read 3 dashes at any point if to rich or lean for the gauge to read it will just show three dashes. Yup car has the High z Fic 2150s on pump right now. I’ve attached a photo for what my injector voltages are at. As far as global fuel that is at -77.7% and global deadtime is at 145.

SasaniFab · Aug 24, 2020

Jason99GSX said:
Yes it is a wideband gauge. And that wideband will read 3 dashes at any point if to rich or lean for the gauge to read it will just show three dashes. Yup car has the High z Fic 2150s on pump right now. I’ve attached a photo for what my injector voltages are at. As far as global fuel that is at -77.7% and global deadtime is at 145.

I’ve never seen a wideband without a numerical readout. The narrow band gauge has dashes.

Jason99GSX · Aug 24, 2020

SasaniFab said:
I’ve never seen a wideband without a numerical readout. The narrow band gauge has dashes.

It has the numbers haha. It’s a normal digital AEM wideband. It displays the numerical readout. But like I mentioned if it goes either to rich or lean for What the gauge can display it will show three dashes instead of numbers till it’s back in range. As far the the voltages and global deadtime etc how do those numbers look?

Vegas Smith · Aug 24, 2020

Just post a log............

Jason99GSX · Aug 24, 2020

Vegas Smith said:
Just post a log............

Vegas Smith · Aug 24, 2020

There is something likely wrong with how your wideband is hooked up. How is it setup to be run in the rear o2 and not the front o2? I've never seen that before. If it is indeed hooked up to the front o2 pin then it needs to be setup like that in link.

Jason99GSX · Aug 24, 2020

Vegas Smith said:
There is something likely wrong with how your wideband is hooked up. How is it setup to be run in the rear o2 and not the front o2? I've never seen that before. If it is indeed hooked up to the front o2 pin then it needs to be setup like that in link.

Does that look like that might be the issue? Right now I have the wideband sensor under the drivers seat area in the test pipe.

jpmxrider489 · Aug 24, 2020

If your trying to rule out a bad regualtor, if you have a free imput, log linear fuel pressure. Your fuel pressure should be your base plus your boost. I personally log fuel pressure as well as a in car gauge.

I would replace your plugs also.

I cant look at the log right now, but my wideband is up front simulating narrowband.

Jason99GSX · Aug 24, 2020

jpmxrider489 said:
If your trying to rule out a bad regualtor, if you have a free imput, log linear fuel pressure. Your fuel pressure should be your base plus your boost. I personally log fuel pressure as well as a in car gauge.

I would replace your plugs also.

I cant look at the log right now, but my wideband is up front simulating narrowband.

Yeah I’m running a fuel pressure in car as well. So I’m able to see it. Another thing I noticed was if I use link with car off and activate fuel pump my pressure will sit right at 43. Then I turn the car on and the pressure is at like 47-48psi back and fourth At idle, is that normal??

jpmxrider489 · Aug 25, 2020

Jason99GSX said:
Yeah I’m running a fuel pressure in car as well. So I’m able to see it. Another thing I noticed was if I use link with car off and activate fuel pump my pressure will sit right at 43. Then I turn the car on and the pressure is at like 47-48psi back and fourth At idle, is that normal??

No, with the engine on, pulling vacume, gauge in the car is 37-38.

Jason99GSX · Aug 25, 2020

jpmxrider489 said:
No, with the engine on, pulling vacume, gauge in the car is 37-38.

what do you think would cause that issue I’m having then with the pressure? I pulled one of the plugs and this is what is looks like right now.

jpmxrider489 · Aug 25, 2020

I would read over this link. It was a huge help for me and its good info to learn. Something has to be up with the regulator itself. Does it have its own vacume source or is it tied to something else?

https://www.sixsigmatuning.com/fuel...xt=Kick the fuel pump on in ECMlink, Misc tab.

Jason99GSX · Aug 26, 2020

jpmxrider489 said:
I would read over this link. It was a huge help for me and its good info to learn. Something has to be up with the regulator itself. Does it have its own vacume source or is it tied to something else?

https://www.sixsigmatuning.com/fuel-system-troubleshooting#:~:text=Most people will simply start,run it by your tuner.&text=Kick the fuel pump on in ECMlink, Misc tab.

It has its own vac source from the intake manifold. I had someone else say it could be that the stock return is restricting and that’s why I’m having issues. Idk if that could be a possibility. But I feel like plenty of people have used stock feed and stock return without issues. I read through that article and I’m starting to think maybe the stock feed and return lines need to be upgraded?

jpmxrider489 · Aug 26, 2020

Jason99GSX said:
It has its own vac source from the intake manifold. I had someone else say it could be that the stock return is restricting and that’s why I’m having issues. Idk if that could be a possibility. But I feel like plenty of people have used stock feed and stock return without issues. I read through that article and I’m starting to think maybe the stock feed and return lines need to be upgraded?

When I first upgrade tons fpr and bought the tank to rail kit from extreme psi and went with 8an. At that time I actually used the factory feed line as the return since its already ran. That would open open the inner diameter of your return as well as the feed.

But at idle, the fpr should always keep pressure at what we said above. But at idle, even with the pump upgrade, your only flowing the same pressure as stock. The stock return would only be restricted at higher boost.

But since you got massive injectors and pump. I would say your fuel lines are your next restriction. But at idle, it doesnt explain why your seeing higher pressure because the regulator should be controlling it. Have you tried the link above?

I have ran a -8 and using the factory feed as a return with my 20g for some time. Then when I cleaned up some lines, I ran a -6 for return. Hope that helped you. But since were trying to rule out a regulator issue, would pull it and do what the link above said.

This is my current fuel line setup.

jpmxrider489 · Aug 26, 2020

After a quick look at your log, it looks like our aemwb and afrest are way off the whole time. So something isnt calibrated right. That same link above, on his site, he talks about aemwb. I could be wrong on this part, but if your wb is in the rear, why are you simulating narrowband? I run mine up front and simulate it, not using a rear o2 at all. I also dont see any misfure related stuff due to the rpm not being jumpy. Is there a way you can log fuel pressure using the MDP input assuming its free on your car?

Since I am simulating narrbowband. My WB switch point is 2.80. I think you are fighting two issues here. I cant tell a fuel issue based on the log since Its not logged.

Jason99GSX · Aug 27, 2020

jpmxrider489 said:
After a quick look at your log, it looks like our aemwb and afrest are way off the whole time. So something isnt calibrated right. That same link above, on his site, he talks about aemwb. I could be wrong on this part, but if your wb is in the rear, why are you simulating narrowband? I run mine up front and simulate it, not using a rear o2 at all. I also dont see any misfure related stuff due to the rpm not being jumpy. Is there a way you can log fuel pressure using the MDP input assuming its free on your car?

Since I am simulating narrbowband. My WB switch point is 2.80. I think you are fighting two issues here. I cant tell a fuel issue based on the log since Its not logged.

Hmm...okay. I’ll checked that link and searched for the wideband info. A lot of info in there. I honestly don’t even know where to start to verify this is setup right. Is there a way I can verify the calibration? Should I change the way the wideband is setup? I followed a write up on here back when I installed it. I didn’t think it would be a problem to run in the rear as I’ve seen many do that before without any issues.

jpmxrider489 · Aug 27, 2020

https://www.ecmtuning.com/wiki/v3narrowbandsim
https://www.sixsigmatuning.com/wideband-o2-sensor-info

Remember, the fpr issue appears to be separate from the wide band issue. I would fix the fpr and then look into the wb. If you weren't 4 hours away, i would totally help out. Everhone has their own way of the switch point.

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