P0300 misfire. Meth related???
Aug 2, 2006 | 10:08 PM
#21
The instructions that came with my Snow kit say:
"Nozzle size may have to be adjusted up or down depending on air fuel ratio(smaller nozzle if starting at richer than 12.5:1) and concentration of methanol(smaller if less than 50% methanol is used). Introducing water/methanol before 4-5 psi boost could result in quenched combustion and engine misfire. The amount injected can be adjusted by pump pressure adjustment.
..............If onset point has to be set too high to avoid misfiring(some detonation experienced before onset), reduce the injection quantity(and I assume lower the onset point). This can be accomplished by lowering pump pressure, reducing nozzle size, or using fresh methanol(less than 1 month since exposed to atmosphere)."
Not that I've tested any of this yet. I finally pulled the kit out of the box after having it sitting on my workbench for almost a year. Just installed the pump, reservoir and nozzle tonight. Thought I had better get the meth installed first after seeing what a 2.75 pulley does for boost.
"Nozzle size may have to be adjusted up or down depending on air fuel ratio(smaller nozzle if starting at richer than 12.5:1) and concentration of methanol(smaller if less than 50% methanol is used). Introducing water/methanol before 4-5 psi boost could result in quenched combustion and engine misfire. The amount injected can be adjusted by pump pressure adjustment.
..............If onset point has to be set too high to avoid misfiring(some detonation experienced before onset), reduce the injection quantity(and I assume lower the onset point). This can be accomplished by lowering pump pressure, reducing nozzle size, or using fresh methanol(less than 1 month since exposed to atmosphere)."
Not that I've tested any of this yet. I finally pulled the kit out of the box after having it sitting on my workbench for almost a year. Just installed the pump, reservoir and nozzle tonight. Thought I had better get the meth installed first after seeing what a 2.75 pulley does for boost.
Last edited by DrX; Aug 2, 2006 at 10:30 PM.
Aug 3, 2006 | 09:41 AM
#23
Launching!
Joined: Jan 2006
Posts: 226
Likes: 0
Originally Posted by DrX
The instructions that came with my Snow kit say:
"Nozzle size may have to be adjusted up or down depending on air fuel ratio(smaller nozzle if starting at richer than 12.5:1) and concentration of methanol(smaller if less than 50% methanol is used). Introducing water/methanol before 4-5 psi boost could result in quenched combustion and engine misfire. The amount injected can be adjusted by pump pressure adjustment.
..............If onset point has to be set too high to avoid misfiring(some detonation experienced before onset), reduce the injection quantity(and I assume lower the onset point). This can be accomplished by lowering pump pressure, reducing nozzle size, or using fresh methanol(less than 1 month since exposed to atmosphere)."
Not that I've tested any of this yet. I finally pulled the kit out of the box after having it sitting on my workbench for almost a year. Just installed the pump, reservoir and nozzle tonight. Thought I had better get the meth installed first after seeing what a 2.75 pulley does for boost.
"Nozzle size may have to be adjusted up or down depending on air fuel ratio(smaller nozzle if starting at richer than 12.5:1) and concentration of methanol(smaller if less than 50% methanol is used). Introducing water/methanol before 4-5 psi boost could result in quenched combustion and engine misfire. The amount injected can be adjusted by pump pressure adjustment.
..............If onset point has to be set too high to avoid misfiring(some detonation experienced before onset), reduce the injection quantity(and I assume lower the onset point). This can be accomplished by lowering pump pressure, reducing nozzle size, or using fresh methanol(less than 1 month since exposed to atmosphere)."
Not that I've tested any of this yet. I finally pulled the kit out of the box after having it sitting on my workbench for almost a year. Just installed the pump, reservoir and nozzle tonight. Thought I had better get the meth installed first after seeing what a 2.75 pulley does for boost.
Hehe... if Doc kept reading he would find the recommended spray points for different setups.... I believe Snow recommends a 1 psi setpoint for start of spray... (on a centrifugal)
My spray starts at 1 psi and goes full at 10 psi with a 625ml..500 hp nozzle...
It took me about 45 minutes to tune the controller... I tried the 375ml nozzle but it wasn't enough....
If you increase the meth content you will loose the cooling effects you are looking for and need... as you are aware...your fueling is fine... you need the water... with my (fresh) 50/50 mix I can drop IAT temps from 135* to 80*and have it climb to 100* by the end of the pull.....Of course I will qualify that with I have absolutely zero experience with a 100% meth concentrate....The mix if tune properly will satisfy your needs. BTW there are numerous logs of mine on HP Tuners that reflect the cooling effects mentioned here....
I think you have found your issue in the controller... we have suspected that for days now... you just have some supporting evidence now to start testing ways to fix it...
Last edited by FlaBouy; Aug 3, 2006 at 09:48 AM.
Aug 3, 2006 | 09:57 AM
#24
Launching!
Joined: Jan 2006
Posts: 226
Likes: 0
Figured I would add this since it was relevant:
Directly from the Snow Forums:
Answered from SnowTech2 in response to wanting to know mix ratios in a 10 psi enviroment.....
"Besides cleaning out carbon, the water turns to steam in the intake and helps remove heat lowering intake charge temp. Nozzle size is a function of boost psi and HP."
and then:
"For your hp and boost start with the 625 nozzle at full pump pressure.
A/F should drop (richen) by about 1/2pt with 50/50 mix, more with more methanol."
Here is a link to their tuning threads:
http://www.snowperformance.net/forum...cf23a768273f6c
Directly from the Snow Forums:
Answered from SnowTech2 in response to wanting to know mix ratios in a 10 psi enviroment.....
"Besides cleaning out carbon, the water turns to steam in the intake and helps remove heat lowering intake charge temp. Nozzle size is a function of boost psi and HP."
and then:
"For your hp and boost start with the 625 nozzle at full pump pressure.
A/F should drop (richen) by about 1/2pt with 50/50 mix, more with more methanol."
Here is a link to their tuning threads:
http://www.snowperformance.net/forum...cf23a768273f6c
Aug 3, 2006 | 10:39 AM
#25
Originally Posted by FlaBouy
Figured I would add this since it was relevant:
Here is a link to their tuning threads:
http://www.snowperformance.net/forum...cf23a768273f6c
Here is a link to their tuning threads:
http://www.snowperformance.net/forum...cf23a768273f6c
Anyone interested in meth injection should check that out. On another note. I just got my new nozzle.
Aug 3, 2006 | 10:03 PM
#28
Originally Posted by FlaBouy
Hehe... if Doc kept reading he would find the recommended spray points for different setups.... I believe Snow recommends a 1 psi setpoint for start of spray... (on a centrifugal)
Aug 3, 2006 | 10:20 PM
#29
Well, the 10GPH jet is in. The kit is set to start spraying at 1.5 psi and hit full spray at 10 psi, verified on the bench. I now have the worst of both worlds. 
My misfire problem is still there but the log is only showing about 1/3rd as many misfires. Maybe 50 instead of 150. So, it sounds like I'm heading in the right direction but I also saw my IAT hit 170 deg. with my timing pulled back to about 14 degrees because of the high IAT.
I'm open to suggestions.
My misfire problem is still there but the log is only showing about 1/3rd as many misfires. Maybe 50 instead of 150. So, it sounds like I'm heading in the right direction but I also saw my IAT hit 170 deg. with my timing pulled back to about 14 degrees because of the high IAT.
I'm open to suggestions.
