Popping sound and 100% Injector Duty?
Popping sound and 100% Injector Duty?
Well I just got back from racing and while racing everyone there said that my car sounded fucked up. They said it was popping alot from around the 1/8 mile mark until the 1/4 mile mark. I was hitting 100% Injector Duty while racing and .89 boost via my PFC. I don't have an air/fuel ration gauge which I should but could it just be that my car was running incredibly rich? I have never heard it before when I raced but I even heard it this time inside the car. I have raced numerous times with the exact same setup but this is the first time I ahve noticed this sound. I don't always hit 100% when I race and I have never paid attention on the times that I do hit 100% if my car pops. I am ordering some larger secondary injectors and a fuel rail soon so that I can keep my Duty Cycle down. What else could it be? Is it anything serious? It sounds like it's coming from the exhaust because the sound was coming through the passenger window. My boost held constant on my gauge and my knock readings were all normal. Any help would be great. Thanks, Scott
That is what I was thinking but I wanted to be sure before I do something wrong and blow my motor. Just cruising back from the race it was running fine and my injector cycles were normal. I need to get my PFC tuned badly but I am afraid to try myself and I also want it dynoed once I put in the larger injectors. So I figured I would have it dyno-tuned at that point.
kortez
Joined: Mar 2001
Posts: 437
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From: Thousand Oaks Ca
If you have ever seen anyine dial in a carburated rotary, they start out rich and jet down from there. When they start out the cars pops/missfires like crazy. They basically lean it out until it doesn't pop and they have power through the RPM band. Sounds to me like you are too rich abd the popping is missfires. Hard to say without watching the run.
Well I have the run on video if I could figure out to host it. You can hear it on the video. XS tuned my PFC for my mods when I bought it but it was just a rough tuning, nothing exact, but I know it is tuned really rich to be on the safe side. Way, way, on the safe side. I need to retune it but I have heard I could blow up my car if I don't know what I am doing so I will wait and have a professional tune it for me.
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Rotary Enthusiast
Joined: Aug 2001
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From: Memphis, TN - wishin' i was back in Ft Worth
wait a minute, is ohio in there somewhere? i've been to new england like 50 times, but i go through tn,va,nj,md and so on.
yeah, def def, definitly ohio.
underwear at k-mart yeah, k-mart
yeah, def def, definitly ohio.
underwear at k-mart yeah, k-mart
Passenger
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With your mods your ar so damn rich it is not even funny. You need to get tuned or grabs some maps of this forum. With your mods there is no need for 1300cc inj. Send out your 850cc to get cleaned. You fuels system with a supra pump is good for 365 or so. I would not spend a bunch of money on INJ. because you dont need them yet. or unyil you go single.
IMO
-Rikki
IMO
-Rikki
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From: CT
rikki..i disagree. My mods are full exhaust, intake, and power fc amd if i run .89 boost i hit 95% duty cycles. Dave at kd dynoed tuned my car at 12 psi to a 11.2 afr. So i know i am not rich, but just perfect. My thesis is that the fd can not run more than 12.5 psi on the stock fuel system.
Well I guess I need to get a hold of KDR for a dyno session. I am planning on going single before next summer, hopefully in the spring so I might as well upgrade my injectors now. Also, is it possible to upgrade my secondaries to 1600cc and swap my stock 850cc into my primaries? Is there any difference between the stock primaries and secondaries like impedence or anything which would not allow for a swap like that? This way I could have 850 primaries and 1600 secondaries. Just a thought. I am looking into a larger single so I assume I will need alot of fuel.
But everyone so far seems to be agreeing about the popping being due to running rich? Would that hinder my performace much? I think my car feels a bit sluggish on the top end. Could just be me and not enough mods. Who knows?
But everyone so far seems to be agreeing about the popping being due to running rich? Would that hinder my performace much? I think my car feels a bit sluggish on the top end. Could just be me and not enough mods. Who knows?
Passenger
Posts: n/a
Originally posted by matty
rikki..i disagree. My mods are full exhaust, intake, and power fc amd if i run .89 boost i hit 95% duty cycles. Dave at kd dynoed tuned my car at 12 psi to a 11.2 afr. So i know i am not rich, but just perfect. My thesis is that the fd can not run more than 12.5 psi on the stock fuel system.
rikki..i disagree. My mods are full exhaust, intake, and power fc amd if i run .89 boost i hit 95% duty cycles. Dave at kd dynoed tuned my car at 12 psi to a 11.2 afr. So i know i am not rich, but just perfect. My thesis is that the fd can not run more than 12.5 psi on the stock fuel system.
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From: CT
rikki....i said there is NOT enough fuel to run more then 12.5 BOOST you are saying there IS enough fuel to run 350 RWHP. We are talking about two different things, no?
My experienmce shows that i am correct while your experience shows that you are correct..which is ok. our experience doesnt show conflicting innfo
My experienmce shows that i am correct while your experience shows that you are correct..which is ok. our experience doesnt show conflicting innfo
fart on a friends head!!!
Joined: Mar 2002
Posts: 4,104
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From: sheppard AFB, TX
i had some problems with that same sort of thing. i was setup like you are. i redid my injectors. send them to rc engineering and get them upgraded (for future use). replace the FPD. replace the lines. its really easy if you go ahead and get rid of your emissions equipment. . . the powerfc doesnt even use that ****. get a block-off kit and do it all at once. redo your vacuum lines also if you havent already. it is very worth it to do this at one time. youll thank yourself in the longrun.
paul
paul
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From: CT
to further the discussion..i think wade has tested to prove you dont need more fuel or an upgraded ecu if you keep boost at stock levels. Thus the real issue when tuning is boost levels not rwhp. One can make great power reliable too if you keep boost under control and at 10 psi or in your case 11 psi.
Passenger
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Originally posted by matty
rikki....i said there is NOT enough fuel to run more then 12.5 BOOST you are saying there IS enough fuel to run 350 RWHP. We are talking about two different things, no?
My experienmce shows that i am correct while your experience shows that you are correct..which is ok. our experience doesnt show conflicting innfo
rikki....i said there is NOT enough fuel to run more then 12.5 BOOST you are saying there IS enough fuel to run 350 RWHP. We are talking about two different things, no?
My experienmce shows that i am correct while your experience shows that you are correct..which is ok. our experience doesnt show conflicting innfo
-Rikki
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Joined: Mar 2001
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From: CT
so rikki...pleae help me...how can i get more rwhp w/o upgrading the inj's. My duty cycles are 95% wiht my current set up. I am afraid to upgrade the IC as i think it will push up my already dangerous duty cycles.
You see i really dont want to run bigger inj cause of all the horror stories that i have read here.
You see i really dont want to run bigger inj cause of all the horror stories that i have read here.
Passenger
Posts: n/a
Matty, What were your dyno numbers? How much HP did you make? It just seems that there is too much fuel for 12 or 13 psi IMO. I did notice whrn I went NON-SEQ that the Duty% did go down. maybe that is why. I had the same problem with SEQ. It would go high or even read MAX on my keypad(PMC).
-Rikki
-Rikki
fart on a friends head!!!
Joined: Mar 2002
Posts: 4,104
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From: sheppard AFB, TX
ive had no probs with my 1300cc/min injectors. what kind of probs have been out there? the only things ive seen are the 1600's tuned with the powerfc. . . get a haltech if your gonna go that big. . . there problem solved. . . or an electromotive. . . or a motec. . . or some other high-end ecu.
paul
paul