yellow light and red temp light when I let off throttle?

[FLYBYU]

What high pressure pump do you have also? Also watch out after you unpinch return line as it will be under pressure!!

 

[MRFUSION]

Sounds like a silly question but do you have a tether system on it?

 

[sledfvr]

I do have a tether, but I bypassed it as a test and had no change. It doesn't seem to be flooding out, it just cuts out for a moment when I let out of throttle under boost and the warning lights come on then it comes back to life right away. I'm going to go try a different o2 sensor. I know that when I let off throttle my afr's go really lean, all five of my turbo yammi's have done this. I know the prologger will slam open the wastegate if it thinks that it is too lean.

 

[MRFUSION]

Okay, we had some relays failing on tethers causing momentary flashing of lights on dash at wide open and deceleration. Sorry no help. Shad

 

[FLYBYU]

Mine had a really weird throttle response when letting off throttle. I can 99 % say that is your problem. You have options here either go back to stock fpr or go aftermarket fpr

 

[sledfvr]

I just tested antoher impulse apex identical to mine other than the fuel tank. The fuel pressure on it reads 47-48psi too. I'm thinking my gauge just reads a little high. This thread is getting long winded so I'm going to swap some parts and post my results. Thanks again flybyu and mr. fusion for the ideas.

 

[MRFUSION]

My Nypex goes lean as well I figured it was from my O2 sensor being close to my exhaust outlet and sees air coming in once you dump it. Good luck. Shad

 

[FLYBYU]

Does it have the boost it system also? That would make sense for higher pressure.

 

[MRFUSION]

It does, but it did it with the Boondocker box as well. my O2 sensor is about 9 inches from where it exits into my tunnel, figured it was getting forced air once dumped.

 

[FLYBYU]

I still say there's something wrong with his fuel pressure regulator. I have 1000 c.c. injectors and it still idles at 38 psi.

 

[Northernboy]

If you are running Boost-It XIC make sure the Lean Warning is disabled. If it sees a lean reading it will dump in a bunch of fuel.

 

[sledfvr]

lean warn is disbled. Anyone want to trade me a hallman rx or aem ebc and aem wideband for my prologger? I have never logged a run with it and I wouldn't mind cleaning up the wiring under the hood. Cost $699 new.

 

[FLYBYU]

I went to the boost it site to learn more about it and it says they won't sell directly to USA no more. That's scary. Does the boost it injectors have a return line to them? Or just a feed line? 42 psi is max it should have in fuel line. You could have even more injectors. The fuel pressure regulator will still maintain that 38 to 42 psi max at idle. Any more or less than that your going to have problems. Check the vacuum line for the fuel pressure regulator. that can blow off.

 

[sledfvr]

Well I went thru all the settings on the prologger and put a new o2 sensor in it. Took the sled for a short run and it worked great. It is amazing how many things you can adjust on the prologger, way more than I need for mountain riding. I did a pressure test on the charge system and found that one of the throttle body boots was leaking a little bit around 12-14lbs of boost. I had to pull the spacer out of the clamp and grind it down a bit so it would clamp tighter. A pressure test every few rides is not a bad idea. Once a year isn't enough. Thanks again for all the suggestions.

 

[sledfvr]

Boost it is the probably the #1 fueling system for mountain riders in the Northwest. They are so busy just with Canadian buyers that they can't keep up, that's why they quit selling to the U.S. Neil, from Boost it is at the top of the game around here. There's lots of extra power to be had by leaving the stock fueling system alone and running external standalone injectors. I had to add weight to my primary and gained 20 miles to a tank of fuel.