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APEX TURBO MISSES AT FULL THROTTLE fuel problem?


Just tried pressurizing the mcx box to 16 psi and it floods the engine. But my pressure goes down to 30 psi. idles at 40 psi. I will try to go for a rip and see if it really drops. If it does then I have pump issues.
 
ok, so I just checked the fuel pressure at idle and its 43 psi. When it boost on the launch master its all over the place. 20 to 60 back and forth so fast u cant see the needle. Actually I am having a hard time making boost with the launch master. It will start to pop and make boost and then just dies to no boost and stays like that till I let off and try again. I have to try really hard to make boost and when I do it drops off after 2 sec to 0 boost. Man I am having a dam hard time with this sled.
 
The 2-step will do that if there is too much fuel or not enough residual heat in the exhaust header to light off the unburned fuel, causes the boost to drop out. So if you were trying the lanuch master before you were up to temperature...
Keep in mind that your fuel pressure regulator is manifold pressure sensitive, so if the pressure (aka:boost and vacuum) is fluctuating all over the place (like what you described when you are on the launch master...) then so will your fuel pressure. Just so you aren't chasing a ghost...
 
Nope, won't hurt a thing... I've over 3 seasons running that tight of a gap, no issues, no cold fouling, etc.
This is the gap I was told to run by Justin at Full Power Performance, it's what he sets all his boosted motors up at (with the stock ignition) due to the tighter gap is shielded more from the turbulent combustion chamber or something like that which prevents the spark from blowing out under boost.
mbarryracing said:
Very well could be electrical and not fueling at all... Something rather simple but have you tried new spark plugs? Could be one or more is actually loosing the spark (blowing out) when the cylinder pressure and turbulance really comes up at WOT loads, I had this very issue on the dyno... drove me nuts trying to find it.

What plugs are you currently running? Don't ever use the dual electrode plugs because they are definitely more susceptible to misfire under boost, run the stock plugs and try gapping them at 0.018"
Click to expand...
I don't know much but I do know this much... it made a night and day difference between misfiring and not for me. I tried the dual gap plugs that stick out into the chamber more, because I didn't listen to Justin, and I had absolutely terrible misfiring... Duh, waste of dyno time $$$ on my part.
 
The little things makes it work. I run a tight gap as well, I have to because running at 22 lbs on water/alcohol to control detonation, the meth tends to put out the fire if I don't, causing misfire at wot.
Glad you got it fixed :)
 
.018 is what I run and what most Gage there plugs to when running boost. You r good to go
 
redrider18 said:
Not to get off topic, but do any of you guys with boost run the CR10EK's?
Click to expand...

mbarryracing said:
Nope, won't hurt a thing... I've over 3 seasons running that tight of a gap, no issues, no cold fouling, etc.
This is the gap I was told to run by Justin at Full Power Performance, it's what he sets all his boosted motors up at (with the stock ignition) due to the tighter gap is shielded more from the turbulent combustion chamber or something like that which prevents the spark from blowing out under boost.
mbarryracing said:
Very well could be electrical and not fueling at all... Something rather simple but have you tried new spark plugs? Could be one or more is actually loosing the spark (blowing out) when the cylinder pressure and turbulance really comes up at WOT loads, I had this very issue on the dyno... drove me nuts trying to find it.

What plugs are you currently running? Don't ever use the dual electrode plugs because they are definitely more susceptible to misfire under boost, run the stock plugs and try gapping them at 0.018"
Click to expand...
I don't know much but I do know this much... it made a night and day difference between misfiring and not for me. I tried the dual gap plugs that stick out into the chamber more, because I didn't listen to Justin, and I had absolutely terrible misfiring... Duh, waste of dyno time $$$ on my part.
Click to expand...
 
redrider18 said:
Not to get off topic, but do any of you guys with boost run the CR10EK's?
Click to expand...
Not off topic, already touched on these above.
Yeah, one word... DON'T!
Basically they extend out into the combustion chamber further (reason they produce more HP on a NA motor, AKA more compression) and hence suffer from what actually caused this whole topic...

mbarryracing said:
...
This is the gap I was told to run by Justin at Full Power Performance, it's what he sets all his boosted motors up at (with the stock ignition) due to the tighter gap is shielded more from the turbulent combustion chamber or something like that which prevents the spark from blowing out under boost.
mbarryracing said:
Very well could be electrical and not fueling at all... Something rather simple but have you tried new spark plugs? Could be one or more is actually loosing the spark (blowing out) when the cylinder pressure and turbulance really comes up at WOT loads, I had this very issue on the dyno... drove me nuts trying to find it.

What plugs are you currently running? Don't ever use the dual electrode plugs because they are definitely more susceptible to misfire under boost, run the stock plugs and try gapping them at 0.018"
Click to expand...
I don't know much but I do know this much... it made a night and day difference between misfiring and not for me. I tried the dual gap plugs that stick out into the chamber more, because I didn't listen to Justin, and I had absolutely terrible misfiring... Duh, waste of dyno time $$$ on my part.
Click to expand...
 
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