LIL BIT OF HESITATION....3800 rpm ??
07-16-03, 11:40 PM
#1
boost on the way(GTU II)
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LIL BIT OF HESITATION....3800 rpm ??
1987 STOCK PORT.....
HEADER /SINGLE EXHAUST/CONE INTAKE.
"all my info "
OK WELL UNDER regular driving conditions such as "not a heavy foot"lol WELL SAY IM DRIVING NORMAL SPEEDS SHIFTING AT NORMAL SHIFTING POINTS.. WELL while ACCELERATING SLOWLY LIKE THAT i feel hesitations in the engine.. sometimes heavy jerks and some times just like the engine is "missing" like maybe a fuel inj is giving not enough fuel or something and the missing and hesitations always stop at exactly 3500rpm( knowing the stock tach is technically 300rpm's off i suggested to myself it was the 3800rpm hesitation) once it stopped at like 4k but only once.......
well on the other hand when i go to hammer the accelerator i feel a different outcome... i fell no "missing" or no "hesitation" at all when i am accelerating quite quickly .
what could that be? ealry stages of the 3800rpm hesitation?OR MAYBE A WHACKED OUT TPS? WEll help me out guys . this post didnt do to well in the 2nd gen sect.
thanks
jack
HEADER /SINGLE EXHAUST/CONE INTAKE.
"all my info "
OK WELL UNDER regular driving conditions such as "not a heavy foot"lol WELL SAY IM DRIVING NORMAL SPEEDS SHIFTING AT NORMAL SHIFTING POINTS.. WELL while ACCELERATING SLOWLY LIKE THAT i feel hesitations in the engine.. sometimes heavy jerks and some times just like the engine is "missing" like maybe a fuel inj is giving not enough fuel or something and the missing and hesitations always stop at exactly 3500rpm( knowing the stock tach is technically 300rpm's off i suggested to myself it was the 3800rpm hesitation) once it stopped at like 4k but only once.......
well on the other hand when i go to hammer the accelerator i feel a different outcome... i fell no "missing" or no "hesitation" at all when i am accelerating quite quickly .
what could that be? ealry stages of the 3800rpm hesitation?OR MAYBE A WHACKED OUT TPS? WEll help me out guys . this post didnt do to well in the 2nd gen sect.
thanks
jack
Last edited by seventhgear; 07-16-03 at 11:45 PM.
07-17-03, 07:45 AM
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Is it a turbo or N/A motor? If its N/A, it could be that the aux ports aren't opening. That or its something to do with the secondary injectors going into batch fire mode. Search the 2nd gen forum cause this happens a lot and there are many good write ups on it. I think you have to check the ground wire off the main harness. If its loose then you it causes this problem. Its normally grounded to the top of the center plate. On S4 models, the EGR valve is there and the ground wire is grounded to that. Don't know about S5 or turbo cars.
Hope that helps.
Hope that helps.
07-17-03, 09:27 AM
#3
boost on the way(GTU II)
Thread Starter
HELPS JUST A LIL THANKS.... its an n/a.. damn i forgot to put that .. im a dumbass ! lol
my aux ports are wired open.... also whats batch fire mode? jw
also the center plate ur talkin about that is grounded by the main harness is grounded on the block . i put it on there before i put the intake on .
jack
my aux ports are wired open.... also whats batch fire mode? jw
also the center plate ur talkin about that is grounded by the main harness is grounded on the block . i put it on there before i put the intake on .
jack
Last edited by seventhgear; 07-17-03 at 09:45 AM.
07-17-03, 09:52 AM
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Ground the car like mad
Check the ECU ground, the coils grounds (they ground via the body), the engine grounds, and put a big fat ground wire from the engine to a clean (bare metal) spot on the chassis.
Check the ECU ground, the coils grounds (they ground via the body), the engine grounds, and put a big fat ground wire from the engine to a clean (bare metal) spot on the chassis.
07-17-03, 05:40 PM
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batch fire mode is when the injectors go from pulse fire to continuous on. Normally, the primary injectors fire in pulses. Front back front back, like that. Under certain loads above a certain RPM, the secondary injectors come on and all 4 injectors fire. I think they either fire at the same time, or they stay on continuously. Do a search in the 2nd gen forum for "batch fire" and I think you will find the thread. Its been a while since i looked into it so I could be describing it wrong.
07-17-03, 05:47 PM
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Here, I found this description which may make more sense.
originally posted by NZConvertible
"Below 3800rpm the primaries fire sequentially. Above 3800 all four batch fire at half the pulsewidth the primaries were firing at before the changeover. So for example if the primaries are opening for 10ms just before 3800, all four will fire for 5ms just after 3800. This means the total amount of fuel being injecting doesn't actually change during changeover."
"Below 3800rpm the primaries fire sequentially. Above 3800 all four batch fire at half the pulsewidth the primaries were firing at before the changeover. So for example if the primaries are opening for 10ms just before 3800, all four will fire for 5ms just after 3800. This means the total amount of fuel being injecting doesn't actually change during changeover."
Last edited by Project84; 07-17-03 at 05:49 PM.
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07-17-03, 10:32 PM
#8
boost on the way(GTU II)
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i have a bunch of grounds dude... i did ground like MaD yO ! 
well i have a tranny groun... a few engine grounds. trailing coil ground.. umm and more but i forget where else. well i get what batch fire is now but why does my car malfunction and "batch" fire? what can i do to fix ity... i just searched and found no answer to n e of those questions except by using an aftermarket ecu...
well thanks for all ur help man
jack
well i have a tranny groun... a few engine grounds. trailing coil ground.. umm and more but i forget where else. well i get what batch fire is now but why does my car malfunction and "batch" fire? what can i do to fix ity... i just searched and found no answer to n e of those questions except by using an aftermarket ecu...
well thanks for all ur help man
jack
07-18-03, 09:42 AM
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Batch firing is not the problem. All rx-7's do it, well the ones we are speaking of, and there is nothing wrong with running our cars like that. Have you ever had your injectors cleaned? Have you tried setting the TPS or checking it? Since it is under light throttle maybe the secondaries are sticking open and flooding the engine a tad. This might be why when you mash it there is no problem. I would pull the secondaries and clean them.
07-18-03, 04:40 PM
#11
boost on the way(GTU II)
Thread Starter
tps has been set numerous times. NUMEROUS !
i have never taken the inj to be cleaned at all..... but i wouldnt mind givin them a good cleaning..... soak them in kerosine, am i correct? i will try swapping ecu's with my spare one.... ..thanks
jack
i have never taken the inj to be cleaned at all..... but i wouldnt mind givin them a good cleaning..... soak them in kerosine, am i correct? i will try swapping ecu's with my spare one.... ..thanks
jack
07-19-03, 12:11 AM
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there are places you can send the injectors to be cleaned. Its way better then soaking them in anything. Check out this site, they have the cheapest prices I've seen for this service.
www.cruzinperformance.com
Click on fuel injector cleaning on the top left. The last time I called them, they were so busy they weren't taking any more injectors. Good info on what they do with the injectors and how they do it.
If your TPS won't stay set, you might need a new one.
www.cruzinperformance.com
Click on fuel injector cleaning on the top left. The last time I called them, they were so busy they weren't taking any more injectors. Good info on what they do with the injectors and how they do it.
If your TPS won't stay set, you might need a new one.
07-19-03, 02:54 PM
#13
boost on the way(GTU II)
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well i switched the sec, inj. with 2 i had in another fuel rail that i know worked fine and they did not do the job . i still have that pesky hesitation.... something tells me this prob is electrical.
damnit i hate electicity sometimes
jack
damnit i hate electicity sometimes
jack
07-19-03, 11:40 PM
#15
boost on the way(GTU II)
Thread Starter
ohh hell yea......damn hesitation is fucklin up my rotation...lol dont ask me what that means...???? lol
but it sometimes looks like i dont know how to drive .....especially in a parking lot looking for spaces.... going real slow in first ..people look at u like ur dumb... n e ways
jack
but it sometimes looks like i dont know how to drive .....especially in a parking lot looking for spaces.... going real slow in first ..people look at u like ur dumb... n e ways
jack
07-21-03, 10:23 AM
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Have you tested your TPS? Make sure there are no spikes in it? You could set it way out of whack, that's what I did when mine was busted, and you car will idle like a camm'ed 454 but you could just try it and see what happens.
Dunno dude.
Dunno dude.
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