I've been sorting out all the kinks on my 2.9L build and am getting confused with the last little issue.
Issue:
The engine falls on its face at WOT above 5k rpm. It will continue to pull to redline but it is choppy and not nearly as powerful as 3/4 throttle. It is fine at 3/4 throttle going all the way to redline, and fine at WOT up to 5k. It almost seems like a fuel starvation issue but I cant identify a culprit that would do it ( see below)
Specs:
M20 2.85L ( S50US crank, eta rods, B25 pistons)
Bimmerheads 272 w/ nuk cam gear
IE HD Rockers
IE headers to custom midsection w/ O2 sensor bung
M52 pink top injectors
SSSquid custom chip to above mentioned specs
Potential culprits:
AFM: Potentially? It worked fine on my car before the build, but it has never seen the higher volume of air before that WOT would give. I could certainly see where there is a dead spot because it is not worn in on the higher airflow.
TPS: I tested the resistance and it works fine at idle and WOT
CPS: doesnt make sense with the issue only at WOT
ICV: doubftful because not idle
Vacuum leak: once again, doesnt make sense to me since it works fine at WOT from 4-5k
Chip: Initial instinct, but i had it reflashed for a few small adjustments i wanted to make ( redline and octane) and it still does it. i am doubtful
injectors: it has done the issue with the M52 pink tops, ford injectors, and known good oe b25 injectors, so i am doubtful
Fuel Pump: I installed a new meyle unit very recently, so I'm doubtful. I can T in a fuel pressure gauge and do a pull, but it gave ample psi at idle. Before the new fuel pump the old one would do the same issue
FPR: maybe? mine appears to work fine at all other situations though.
Spark Plugs: New Bosch units, i used the same type on my old b25 and they worked well, and I'm unsure how the WOT would affect this.
Ignition coil: potentially? I believe its still the original one, but it works fine at 3/4 throttle so I'm doubtful.
Does anyone have any ideas?
Thanks!
-Ken
Issue:
The engine falls on its face at WOT above 5k rpm. It will continue to pull to redline but it is choppy and not nearly as powerful as 3/4 throttle. It is fine at 3/4 throttle going all the way to redline, and fine at WOT up to 5k. It almost seems like a fuel starvation issue but I cant identify a culprit that would do it ( see below)
Specs:
M20 2.85L ( S50US crank, eta rods, B25 pistons)
Bimmerheads 272 w/ nuk cam gear
IE HD Rockers
IE headers to custom midsection w/ O2 sensor bung
M52 pink top injectors
SSSquid custom chip to above mentioned specs
Potential culprits:
AFM: Potentially? It worked fine on my car before the build, but it has never seen the higher volume of air before that WOT would give. I could certainly see where there is a dead spot because it is not worn in on the higher airflow.
TPS: I tested the resistance and it works fine at idle and WOT
CPS: doesnt make sense with the issue only at WOT
ICV: doubftful because not idle
Vacuum leak: once again, doesnt make sense to me since it works fine at WOT from 4-5k
Chip: Initial instinct, but i had it reflashed for a few small adjustments i wanted to make ( redline and octane) and it still does it. i am doubtful
injectors: it has done the issue with the M52 pink tops, ford injectors, and known good oe b25 injectors, so i am doubtful
Fuel Pump: I installed a new meyle unit very recently, so I'm doubtful. I can T in a fuel pressure gauge and do a pull, but it gave ample psi at idle. Before the new fuel pump the old one would do the same issue
FPR: maybe? mine appears to work fine at all other situations though.
Spark Plugs: New Bosch units, i used the same type on my old b25 and they worked well, and I'm unsure how the WOT would affect this.
Ignition coil: potentially? I believe its still the original one, but it works fine at 3/4 throttle so I'm doubtful.
Does anyone have any ideas?
Thanks!
-Ken
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