Fuel pressure on M8PGT Boonie

[GF2]

My sled runs perfect at 5 to 6 # when I turn up the boost higher it is cutting out on the upper end , one cylinder will go really cold say 900 in one side and 4 or 5 in other , if I let off the gas the other cylinder will catch back up in a couple of seconds. at times when there is very little load I can get it to clean up at 8 or 9 pounds or so and it will rip , my numbers are 22 35 46 I have added and subtracted on the 46 with no change .

I had brand new plugs gap are .20

Is there any way to reduce fuel pressure on this system Im assuming that mine is to high at 45 # and adjustment might be wasteing my time and race fuel.

Has anybody had this fuel pressure issue on there pgt need a solution.

 

[oys]

Same exact issue on mine. 07 M8 with the brand new BD PG EBC W/ intercooler. Seems to run better at 4-5 lbs. When I try to clean up the top end, no luck. Wondered about fuel pressure as well. EGT's have run cool the whole time, no codes until last ride when it threw a 23 and then lost power. Sled fires up but sounds horrible! Now I get to tear it down and see what happened. Be careful of the whole "runs cool" thing. Mine was the same way right until something let go.

I'll keep you posted on what I find. Good luck on yours.

 

[mynewuseddoo]

If it's running too lean it will run cool also.

 

[Woody67]

if the det protection system is activating it can easily be mistaken for a fueling issue. The ecu is adding fuel and retarding the timing and causing the misfire to keep the motor from burning down.

This may not be your issue but on my sled 1/2-1 lb can be the difference between perfect running and misfiring. No fueling adjustment will cure it but if I turn the boost up anymore it goes past the misfire and throws the ECU 21 det code.

I have tested this on numerous conditions and always the same result too much boost for fuel/elevation/compression and misfire will occur bring it down a 1/2 to 1 lb and runs sweet.

 

[GF2]

I was running 50 / 50 110 and 91 at 6000 ft so detonation was prob not my issue because this issue happens even at 6.5# of boost never any codes .

I run koso guages and my highest temp wa 1220 and that was a long pull full throttle in 18 " of fresh.

Oh my duty cycle was 86 % output so good there also.

Has any one put in a inline fuel regulator in ?
Mallory makes one for fuel injection application with a guage port also , and is adjustable from 30 psi to 70 I believe .

Has anyone else had stock fuel pump pushing 45# fuel pressue or is mine extremely high , and did you have any luck tuning at that pressure.

 

[MCIVER]

I know you said it has new plugs but, pull them out, grab another set and make the gap .18. I have had many sets of new bad plugs and this is the quickest thing to change. this is something that is always over looked by many.

 

[JHG]

What year and how many miles on the sled? How old is the turbo kit?

 

[GF2]

This is a 09 with 2200 miles 200 miles on turbo and the turbo kit is a 09 kit with a ada controll box.

keep in mind the sled runs flawless at 5 to 6 # s so reeds I think are fine . and compressoin is good within a pound or so.

I will change the plugs and re gap them yes cheap and easy thing to do.

 

[YETIms]

you need to replace the pump with a new generation walbro. and use a pressure regulator.

7 is the limit for oem pump

 

[glassman]

I have a rg kit and my fuel pressure at idle is about 39 lbs. I have an external regultor with an aftermarket fuel pump. I checked the factory manual and the stock pressure is 42.8 lbs. My 09 runs perfect on the top end with similar tuning numbers but is a little flat on the bottom end so im going to turn it up to 42 lbs. I can run it on pump at elevation without the extra injectors and only get to 7.5 lbs at 6000 ft before i run out of injector.
It seems you really have to have your starting pressure proper for the 1 lb - 1lb boost factor on the top end. That being said if these kits are designed to piggyback the stock fuel system and only add fuel for boost, why dont all the kits use the stock fuel pressure as a starting point? If you are at 45 lbs, and are trying to add more fuel on boost, your factory fuel pump will probably run out of fuel, and you should be close to running out of injector.

 

[jgw50]

Its the crappy BD $.99 FPR! I just replaced mine and it was all corroded under the copper cap. My fuel pressure was at 45. Brought it down to 37 and my bottom end is AWESOME, now I just need to drop boost a little as I get less fuel for same duty cycle and I am border line. I might try 39 psi too.

I used the MSD 2222 regulator and it works great. I bet BD's budget regulator causes a lot of people out there a lot of grief!