semi disgrutled

[tinman22]

ok, did I miss the fine print where it says when running the McRat tune you MUST have a lift pump? i'm suffering from multiple p0087 codes at the track. lol first one I thought might be a high milaged fuel filter but I changed that and tonight I was almost beaten by a POS 1980 something bmw. so here come my questions. what would be the steps to fix this. sicne this is a daily driver i'll assume that the race valve isnt the best choice, nor is it nessecarily the fprv thats the problem. looking at my logs the desired fuel rail pressure is 26107 psi. but the fuel rail pressure falls off as low as 18840 psi at about 2600 rpm. so I saw a set of kennedy twins on a DP members truck and thought they looked nice, clean, simple, efficient. i'm a little leary of the 1792 from some of the new threads I have been reading about them leaking. any input woudl be greatly appreciated. i'd like to see if I can get this fixed up by wed for the next track night ( weather permitting, snow in the forcast)

other than that, i'm not really all that disgruntled. 13.85 at 98 mph with an 8000 psi low fuel rail isnt all that bad. and I kinda figured the fuel system was gonna need help before went in on the efi live .

so :rockon: with the program. and :cussing: for the factory fuel system

TIA for any help

 

[ripmf666]

the 1792 is fine, mine wasnt leaking as bad as we thought, tights bolts on motor think vibrations did it, the only thing we found was that the filter that is built in was sucked shut, As of right now im running the PPE Hot+2 on level 6 with the factory FPRV not shimed and holding 25800 to 26k,

Good Luck

 

[Kat]

We have 1792's on our 3 trucks with no problems

 

[sweetdiesel]

13.85 and your dropping fuel rail pressure i would be pleased as peach
in a cc ,Is this a EFI tune or superchip?

get a fuel pump i dont see many people that race with out them
there all good its how much you want to spend
i just think that positive pressure on the cp3 is a good thing on any pump for that matter


fue race valve i would not have any hesitation on doing either
cheap insurance IMO, Not sure if they are needed on the lbz or not
i just know if i had a choice i would put one on my truck
could do a bottle test to determine if you have a problom with frpv

 

[tinman22]

lol i'm not really disgruntled sweetdiesel, I knew I had a 95% chance of having to go this route. and I am happy with the times. yes its Pats tune with efi live.
kat woudl it be possible to get a photo of the 1792 mounted and plumbed? my dilemma is that I liked the simplicity of the KD twins, but he said that since I plan on adding an extra capacity fuel tank in the future that i'd have to mount it in an alternate location from where it would normally be. i'm curious as to how big the 1792 is. i'm assuming its similar to a holley blue pump.
also i'm pretty sure its not the fprv i'd bet that if I put a guage on my fuel line it woudl be in a vaccum before the stock pump since I go to teh track with barely 1/4 of a tank of fuel to try and keep weight down to make up for the added goodies. so i'm assuming the pump trying to suck through a coffee stirrer straw from the bottom of the tank makes things difficult lol

 

[serpa4]

I was able to squeeze 486 hp/909 tq with mcrate and no lift pump, exhaust, intake, or race valve. It never thew a code for the first month or month and half. However, I'm suspecting I now have a clogged filter. I installed a race valve and KD pumps and now, about a week later, threw my first low rail pressure code, P0087. KD says my pumps may not be primed! I need to check this out tomorrow. My pre vavle, liftpump rail pressure was desired 26,000 actual 20,500 or so. Sure puressure was down, but ran fast and a ton of hp/tq. Very happy. I hope my serious violent surging is due to a clogged filter. I have a new one today and will install tomorrow. Someone gave me a nice tune, tirefryer something. Based on the McRat, but lots more power under 2,000. Love that tune a lot. EFI is sweet, but would really like DSP5 support and TCM support. I miss the Edge J/A combo for its on the fly changes, but the McRat/EFI combo is tops.

 

[tinman22]

hmm so you added the lift pumps and valve and then started having problems? that doesnt sound good.