Been going strong for 6-7 months on a new Vortech V2 kit with tuning help by TimRod. Have a new Walbro 255lph and 3.12 pulley on the way to up the boost soon. AFRs have been steady under 11.5 at full boost (8 psi). Took her for a rip the yesterday and luckily looked down at Innovate Wideband to see AFRs approaching high 13's near 5.5- 6k. Shut it down.

FMU with Auxiliary pump all checked out (pump tested using over 500rpm mode), switch backed to 1500 rpm and 1.1 psi and same issue, changed to over 3k rpm only and same issue.

Have checked all other settings.

Do you think this could be the stock fuel pump going out? Wideband out of calibration (seems close to 14.7 at idle...)? Issue with a stock injector?
Not looking to ditch FMU and Auxilary if I do not have to. Will have Walbro in by end of week.

 

You probably don't have a way to monitor fuel pressure... Maybe you can setup a mechanical gauge, put it somewhere in sight or record it with a gopro etc under load.

I found out I didn't have enough fuel pump by pointing a gopro at my fuel pressure regulator w/gauge and recording it under WOT.

I'm not familiar with the FMU/AUX unit or what you can see in a datalog. I've been working through my own issues and have been comparing datalogs against older known good logs.

 

A few points to consider-
Tim knows his **** about this kit, mb hit him up with questions.
If you're trying to run that V2 on 440 injectors I'd rethink that and go bigger. I see story after story about guys who have to keep upgrading injectors. Your new pump should work for what you're doing.
Another good resource is our new mod bealjk. He writes his own maps, super-helpful guy. GL!

 

Stock injectors are 290cc if you looking to upgrade on the low low, get a set of R35 injectors. Those are 570cc so a little under double the size. That should allows you to hit 500whp on pump. But in the real world you want to just upgrade to 1000cc, 250 or 340 pump and a CJM FRS and call it a day.
I think I have 750cc injectors and they were starting to max out at 550whp. Now that was with 53psi base fuel pressure,I can ramp up my fuel pressure and be on my way, but that is not the right way to fix it.

You are supposed to free air calibrate widebands every 5000 miles or so if running pump gas. It's more often if running E or crazy fuel.

 

Tim definitely knows his stuff! He will chime in when not building that monster .

I have been planning to do the free air calibration, but I’ll be surprised if that does it as the idle is spot on at 14.7 and it drops to 12.5 under WOT and then starts rising as opposed to dipping into the 11s after a couple pounds of boost.

 

Hi Scott,

Did this just happen when you added the 3.12 serpent pulley?
What size injectors? Stock?

The way to verify Lack of Fuel, is to monitor Fuel Pressure, If pressure drops in the higher boost range then you are running out of fuel.
The 3.12 pulley is pushing it with the stock Vortech FMU & Fuel Pump System. Pretty sure we talked about this before.
The 3.12 should have you in the 10psi range, and the FMU is an 8 to 1, so 10psi x 8 = 80psi + plus your Base Fuel Pressure of at least 40, so 80 + 40 = 120psi fuel pressure. ( some kits came with an 6 to 1 and that would drop it about 20psi)
Neither the Walbo or the Vortech Pump work well at these pressures........

The Fix is a Return Fuel System with Regulator, 600cc injectors ( max you want to go with the Split Second Box) and a DW 300 Fuel pump.
Best to do a fuel system with a New Feed line, like a CJM Stage 2 as it has a 1/2" Feed. This will make your life much much easier.

One other thing that people overlook is a Dirty MAF Sensor. If it gets dirty it will read low, thus less fuel. But I pretty sure the problem is you fuel system.
Clean it with CRC electronic Cleaner. Spray it Heavy and let it dry, then do it 4 more time. You need to remove to it from the intake tube.

Hope this helps......
TimRod

 

Hey Tim! Haven’t made the pulley change yet, this is still same setup. Going to try cleaning the MAF today and go from there!

 

Cleaned MAF with CRC cleaner, but it did not look dirty to start. Recalibrated wideband as well, no improvement. It’s seeming like the FMU, factory pump, auxiliary pump, or injectors...

Confirmed that inline runs. Will be putting a Walbro 255 in on Friday.

 

The 255 maybe made a slight difference, but still lean. Auxiliary pump? FMU? Going to get a gauge on it...

 

Take my advice from above, and make it easy on yourself.....

 

Going to throw the tester on tonight. I would love to upgrade the whole fuel system, but in the good old Republic if California that’s an immediate fail on smog.

 

I'm in Commiefornia too... thankfully I'm in a non smog county. If I did have to smog my car... honestly, I'd just remove the Vortech and fuel system to make my car appear stock as possible. If I ever get cited and sent to a ref... this is exactly what I will do. All I need at this point is a un-molested fuel pump basket, factory cats and I could return my car to 'stock'.

 

I am uploading a video as we speak. I am thinking the FMU crapped out. 55-57psi at idle, when I go WOT it goes a touch over 60 before dropping back to 55-57. Not climbing in boost as it is supposed to. No vacuum leaks and the Aux Pump is working.

 

Horrible vid...4:00 and 6:30 best time stamps

 

Scott,

Fuel Pressure should be well past 90 @ 8 pounds of boost.

Stock injectors? Or Larger?

How do you Know aux Pump will flow under Pressure? Wondering how you tested it?

I have an old Vortech Pump if you need it. Had a Vortech FMU but sold it.....

TimRod

 

Tim,

Sent you these. Anyone have any idea what the hell could have happened? I even cleaned the diaphragm off a bit before the picture. I‘m taking the whole thing out to see how it failed....

WTF!?

???

 

You are Right!

FMU is Bad. It’s from moisture in the Fuel.

You can clean the corrosion out, and get a rebuild kit. Try SuperchargersOnline for a better price.

Kit comes with all new insides.

TimRod

 

Special thanks to Jamie at Vortech for getting me a new FMU and getting her ripping again. 11.5 AFR to redline!

 

Thats Awesome Scott!