half thottle bogging
#1
half thottle bogging
before I begin let me say I have read every thread on bogging hesitation on here.
ok my issuse is anything over half thottle my car boggs hard. i have an apexi neo as soon as I hit 100% any more on the pedal just boggs
car: 88s4 na
mods are:
tb mod, emission delete, no aux sleeves,slight ported intake manifolds. hot wired fuel pump, premix, no omp
things I have done: set tps, fixed a fuel leak, fuel filter, new plugs,tried 2 differant sets of plug wires, cas was stabbed correctly by rotary mechanic, fixed vac leaks, I have a fuel pressure gauge in line sits at 40 psi.
basicly I am running out of ideas, any other ideas are welcome.
this is the same setup I had on my other engine be fore it blew. and I never had this issuse .this engine is a rebuilt street port, I have about 220 miles on it and it hasnt been redline or abused. the way it drives is half thottle up to 3k to 4k.
ok my issuse is anything over half thottle my car boggs hard. i have an apexi neo as soon as I hit 100% any more on the pedal just boggs
car: 88s4 na
mods are:
tb mod, emission delete, no aux sleeves,slight ported intake manifolds. hot wired fuel pump, premix, no omp
things I have done: set tps, fixed a fuel leak, fuel filter, new plugs,tried 2 differant sets of plug wires, cas was stabbed correctly by rotary mechanic, fixed vac leaks, I have a fuel pressure gauge in line sits at 40 psi.
basicly I am running out of ideas, any other ideas are welcome.
this is the same setup I had on my other engine be fore it blew. and I never had this issuse .this engine is a rebuilt street port, I have about 220 miles on it and it hasnt been redline or abused. the way it drives is half thottle up to 3k to 4k.
#6
Moderator
iTrader: (1)
Is your fuel pump stock or not? If it is then disconnect the vacuum hose to the FPR after the car has been idling and warmed up some and see if there is vacuum coming from the hose or not. There should be vacuum and if there isn't then the FPR solenoid is not working properly. If there isn't vacuum then the fuel pressure gets bumped up from a normal 30 psi to about 40 psi which can be too much for the car. In a normal situation, the pressure should be close to 30 psi and removing vacuum from the FPR causes the pressure to rise to 40 psi.
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#13
Sharp Claws
iTrader: (30)
probably not with the emissions delete. probably ran to the wrong port on the UIM pre-throttle body. that is about the only place where there won't be a vacuum signal. that or the fuel pressure regulator is bogus.
but yeah, if it's giving vacuum to your FPR port and the pressure isn't changing at all then your regulator is poop. still won't really explain the bogging issue though as that pressure is fine for a load, will be slightly rich out of load.
i'm still betting the AFM setting for the neo got defaulted somehow or the wiring was done improperly. in some cases you can drive the car without the AFM but it won't enrich the fuelling as needed when accelerating. so if the AFM wire patch was unsuccessful or the settings improper, yeah... no fuel no go.
but yeah, if it's giving vacuum to your FPR port and the pressure isn't changing at all then your regulator is poop. still won't really explain the bogging issue though as that pressure is fine for a load, will be slightly rich out of load.
i'm still betting the AFM setting for the neo got defaulted somehow or the wiring was done improperly. in some cases you can drive the car without the AFM but it won't enrich the fuelling as needed when accelerating. so if the AFM wire patch was unsuccessful or the settings improper, yeah... no fuel no go.
Last edited by RotaryEvolution; 12-11-11 at 05:07 PM.
#19
talking head
try taking the tps off the car,, then test it throughout the stroke
,, you are looking for a point that is open circuit or a short that is in the mid stroke of the tps
this bad spot on the reostat wiper will make the the stock ecu freak out and run with these issues
my guess is open circuit and when the signal restores
then the ecu interprets this as the initial off idle signal
and gives the engine a squirt of extra injection timing thinking the motor requires the accelerator pump shot
,, you are looking for a point that is open circuit or a short that is in the mid stroke of the tps
this bad spot on the reostat wiper will make the the stock ecu freak out and run with these issues
my guess is open circuit and when the signal restores
then the ecu interprets this as the initial off idle signal
and gives the engine a squirt of extra injection timing thinking the motor requires the accelerator pump shot
#21
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a few other things, the bat terminal on the alternator may not be tight. your fuel pump hotwire may be iffy (rewiring it is cheap and easy), yes the battery terminals, or a bad battery may be the issue, knock off or broken fpr?, theres alot of those. and if you got it from ebay, have it checked to see if it funtions proper) faulty tps, a anolog meter works really well for checking for a bump. another common issue is the O2 sensor circut, try unplugging it and see if problem persists. bag plugs??? vaccume leak?
#22
so for any one who said neo settings you were right, i knew i set the mode car type things like that. but i guess it didnt take so the other night i reset everything , woke up the next morning and bam it revs fine i can open my secondary thottles with no problems.
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