Fueling?

Bustedsm

Bustedsm

Numbered Car Crazy
When do the fuel pump and injectors come into play when running more boost? The truck right now is knocking pretty crazy and I think it is because of my high IDCs but I'm unsure. Nobody has helped me with my knock post in this area so I figured I'd ask some more questions.

The car currently has a stock pump and stock injectors and it's running right around 15-16psi. I'm also running a mixture of 7 gallons E85 and the rest pump 93 but I still get 7-8 counts of knock.

How often do stock knock sensors go out?
 
S

syclone0209

Member
Re: Fueling?

why are you mixing e85.. It requires more fuel per unit of air to achieve the desired a/f ratio. yes it has a higher octane but your handicapping your already overworked injectors.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

syclone0209 said:
why are you mixing e85.. It requires more fuel per unit of air to achieve the desired a/f ratio. yes it has a higher octane but your handicapping your already overworked injectors.
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I mixed E85 because I'm not aware of how well our trucks would like straight e85 with stock everything. Obviously the injectors and pump can't make up for the extra load but that's not exactly what I was worried about only putting in 7 gallons to finish off the tank.
 
NecroWolf

NecroWolf

lost marbles member
Re: Fueling?

without increasing the fuel tables on your chip aprox 30 percent you'll just burn up your motor if it even runs trying to run straight e85. take the e85 out. if you need more octane get some real high octane.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

NecroWolf said:
without increasing the fuel tables on your chip aprox 30 percent you'll just burn up your motor if it even runs trying to run straight e85. take the e85 out. if you need more octane get some real high octane.
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I've tuned it for the E85, that's not the problem. I'm not new to tuning with E85 as I've been doing it for like a year with my DSM(s).
 
NecroWolf

NecroWolf

lost marbles member
Re: Fueling?

do you have good fuel pressure when you get the knock and what are is your afr then?
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

NecroWolf said:
do you have good fuel pressure when you get the knock and what are is your afr then?
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I've taken the AFR from 10.2x all the way and in between 11.6x. I've posted Tunerpro logs and whatnot in another thread :tup:
 
NecroWolf

NecroWolf

lost marbles member
Re: Fueling?

you tried pulling some spark to see if it helps? you could have carbon build up, a loose tranny line or who knows what else
 
S

SCWolverine

New member
Re: Fueling?

Stock pump??? (1st thing to fix, they have their hands full w/ stock boost).

Injectors shouldn't be an issue unless clogged (filter too).

Swap the knock sensor if you have doubts (be sure to tighten to spec).

Where is it knocking? (shifts?...) (I d/l'd your log from the other post and just see a 12 record loop...)

You said you've tuned it for the E85, did the knock situation change?

You almost seem offended that ppl suggest you ditch the E85, but it's heading in the wrong direction if your fueling system is already overtaxed.

I'd def pull timing and boost until you get sorted.

"Real" race gas will tell you if the knock is false.
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Fueling?

The stock Injectors definately don't have the fuel flow capability to take advantage of the benefits of E85 (ie more boost) The guy running stock turbo/injectors are reaching 100% Injector PW in the 12's (not on E85). The people pushing the limits of the stock injector are having to use high base pressure to compensate.
 
turbodig

turbodig

Active member
Re: Fueling?

Sy#2661 said:
The stock Injectors definately don't have the fuel flow capability to take advantage of the benefits of E85 (ie more boost) The guy running stock turbo/injectors are reaching 100% Injector PW in the 12's (not on E85). The people pushing the limits of the stock injector are having to use high base pressure to compensate.
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What he said. I've had Tys that ran out of fuel with 50# injectors at ~15 psi on E85.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

I'm starting to believe that I'm having issues with phantom knock because I've cranked the timing down and I'm still getting the same amount of knock no matter what. Carbon build up at 155k?
 
WyoSyclone

WyoSyclone

Active member
Re: Fueling?

Bustedsm said:
I'm starting to believe that I'm having issues with phantom knock because I've cranked the timing down and I'm still getting the same amount of knock no matter what. Carbon build up at 155k?
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In the words of a very wise flight instructor.... "always trust your instruments"

You have to work on the premise that you have knock, especially if indicated by DM or TunerPro..

I'd suggest taking a step back, creating a baseline (Premium fuel only, 15lbs boost, 6 degrees advance at WOT).... check the results, then add boost up to your target boost always checking for KR... if none, then start adding some timing. From what I've read so far you're kind of bouncing around without having established a good baseline.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

WyoSyclone said:
In the words of a very wise flight instructor.... "always trust your instruments"

You have to work on the premise that you have knock, especially if indicated by DM or TunerPro..

I'd suggest taking a step back, creating a baseline (Premium fuel only, 15lbs boost, 6 degrees advance at WOT).... check the results, then add boost up to your target boost always checking for KR... if none, then start adding some timing. From what I've read so far you're kind of bouncing around without having established a good baseline.
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The E85 is out of the tank and it's a fresh base of 93 octane. Set for right around 15/16lbs of boost, and timing is way down. I'll have to set another log on the way to class later on.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

? Still have to go with phantom knock but want to get some other opinions on what you guys think.
 
WyoSyclone

WyoSyclone

Active member
Re: Fueling?

Sorry Busted, I'm down in Fort Collins right now... won't be back till tomorrow night, so sometime Tuesday before I can look at your logs.
 
Bustedsm

Bustedsm

Numbered Car Crazy
Re: Fueling?

No problems. I'm possibly going to grab some higher octane gas to toss to see if the knock goes away. If it does then it isn't phantom and I've got some tuning issues on my hand.
 
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