Why a 6k wall and huge backfire?
11-23-04, 08:23 PM
#1
Why a 6k wall and huge backfire?
I have had this problem of hitting a 6k wall through any gear.
I asked several rotary people, even chris at pinapple racing, said it was fuel cut.
I got my CDE fuel cut defenser today, installed it, and its still there.
Right after I hit 6k, BAM- huge back fire and no more go. It sounds like its comming from under the hood. I know my exhaust isnt quite sealed up, I did the water treatment for carbon, and saw steam comming out the DP gasket and wastegate plate.
With a mildly ported wastegate and FCD- hitting 9psi and holding it strong is no problem
. However I would like to be able to go above 6k 
. My timing is nearly dead on, new plugs, and cleaned fuel injectors. Mabey my fuel filters clogged?
I asked several rotary people, even chris at pinapple racing, said it was fuel cut.
I got my CDE fuel cut defenser today, installed it, and its still there.
Right after I hit 6k, BAM- huge back fire and no more go. It sounds like its comming from under the hood. I know my exhaust isnt quite sealed up, I did the water treatment for carbon, and saw steam comming out the DP gasket and wastegate plate.
With a mildly ported wastegate and FCD- hitting 9psi and holding it strong is no problem
. However I would like to be able to go above 6k . My timing is nearly dead on, new plugs, and cleaned fuel injectors. Mabey my fuel filters clogged?
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11-24-04, 01:42 AM
#9
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Originally Posted by VietFC
I believe it wouldn't matter since the S4's use a short range TPS. It would just use the value it sees at the pressure sensor
The S5 TPS uses the narrow-range TPS almost the same as the S4 does.
So having the same symptoms will affect both S4 and S5 ECU's.
Too high of a full-open TPS resistance (typically over 6.0k-ohms), this CAN induce high RPM hesitations.
-Ted
11-24-04, 03:06 AM
#10
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Originally Posted by RETed
Please don't reply if you don't know what you're talking about.
The S5 TPS uses the narrow-range TPS almost the same as the S4 does.
So having the same symptoms will affect both S4 and S5 ECU's.
Too high of a full-open TPS resistance (typically over 6.0k-ohms), this CAN induce high RPM hesitations.
-Ted
The S5 TPS uses the narrow-range TPS almost the same as the S4 does.
So having the same symptoms will affect both S4 and S5 ECU's.
Too high of a full-open TPS resistance (typically over 6.0k-ohms), this CAN induce high RPM hesitations.
-Ted
11-24-04, 03:14 AM
#11
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Hey ted, he said "I believe" wich means that its his opinion and not fact. Those kinds of sentence starters are subject to "correct me if im wrong".
rexman, so your tps checked out on all ranges? and when you replaced it the problem went away? dayum.. makes you wonder how to really tell if you do have a bad tps..
rexman, so your tps checked out on all ranges? and when you replaced it the problem went away? dayum.. makes you wonder how to really tell if you do have a bad tps..
11-24-04, 05:09 AM
#12
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Originally Posted by BlaCkPlaGUE
Hey ted, he said "I believe" wich means that its his opinion and not fact. Those kinds of sentence starters are subject to "correct me if im wrong".
Should we break out the lawyers now?
I'm worried statements like that would leave people who don't know better into bad intepretation.
I prefer to not comment on a problem if you're not absolutely sure and/or have direct person experience to back up your claims.
What would happen if we all start suggesting possible fixes that might or might not work?
Oh waitaminute, we already do that on here...
-Ted
11-24-04, 12:02 PM
#13
I will pull the plug and see what happens. I noticed if I adjusted the dsahpot per instructions on my FCD it loweres the cut voltage, and the 6k hesitation is now a 6.2k hesitation. I tweaked it back to origonal, since fuel cut works awsome.
My TPS is recently replaced off a known good running car.
My TPS is recently replaced off a known good running car.
11-24-04, 12:06 PM
#14
Originally Posted by Terrh
intercooler hose blowing off under boost, maybe?
Hurm....
11-25-04, 04:35 AM
#15
yeah man i replaced the tps with a mazdatrix brand new one and it totally went away. the thing is, i know it was the tps because i tried it on a non turbo 88 and a turbo 87 and it did the same thing on both... at wide open throttle it would get around 6k and completely cut out or wall like you're talking about. save yourself some headache and spring for a new one, you won't be disappointed. i never did understand why it would check out ok on a multimeter, but as soon as it's on the car and you hit 6k it would do it every time. i guess using a multimeter to check a tps is not as fool-proof as everyone thinks.
11-25-04, 04:36 AM
#16
yeah man i replaced the tps with a mazdatrix brand new one and it totally went away. the thing is, i know it was the tps because i tried it on a non turbo 88 and a turbo 87 and it did the same thing on both... at wide open throttle it would get around 6k and completely cut out or wall like you're talking about. save yourself some headache and spring for a new one, you won't be disappointed. i never did understand why it would check out ok on a multimeter, but as soon as it's on the car and you hit 6k it would do it every time. i guess using a multimeter to check a tps is not as fool-proof as everyone thinks.
11-25-04, 04:37 AM
#17
yeah man i replaced the tps with a mazdatrix brand new one and it totally went away. the thing is, i know it was the tps because i tried it on a non turbo 88 and a turbo 87 and it did the same thing on both... at wide open throttle it would get around 6k and completely cut out or wall like you're talking about. save yourself some headache and spring for a new one, you won't be disappointed. i never did understand why it would check out ok on a multimeter, but as soon as it's on the car and you hit 6k it would do it every time. i guess using a multimeter to check a tps is not as fool-proof as everyone thinks.
11-25-04, 04:37 AM
#18
yeah man i replaced the tps with a mazdatrix brand new one and it totally went away. the thing is, i know it was the tps because i tried it on a non turbo 88 and a turbo 87 and it did the same thing on both... at wide open throttle it would get around 6k and completely cut out or wall like you're talking about. save yourself some headache and spring for a new one, you won't be disappointed. i never did understand why it would check out ok on a multimeter, but as soon as it's on the car and you hit 6k it would do it every time. i guess using a multimeter to check a tps is not as fool-proof as everyone thinks.
11-25-04, 05:42 AM
#19
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Originally Posted by rexman13b
i never did understand why it would check out ok on a multimeter, but as soon as it's on the car and you hit 6k it would do it every time. i guess using a multimeter to check a tps is not as fool-proof as everyone thinks.
Do you know how to even use a DMM properly?
-Ted
11-25-04, 06:05 AM
#20
yes i do, and you can't tell me that using a multimeter is a %100 way of checking whether or not a tps is bad. because even with the bad tps, it checked out fine with a dmm, but the true test was on the car and it was crap. i know you seem to be the man about this ****, but you don't need to cop an attitude with me and i don't appreciate it.
11-25-04, 06:06 AM
#21
and if using the dmm is the right way, why didn't mazda dealships use one? they have special tools for that, and i'm sure they can determine whether or not a tps is bad better than a dmm. that's all i have to say about it, i'm not gonna argue with a guy 2000 miles away.
11-25-04, 09:12 AM
#22
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Originally Posted by rexman13b
yes i do, and you can't tell me that using a multimeter is a %100 way of checking whether or not a tps is bad. because even with the bad tps, it checked out fine with a dmm, but the true test was on the car and it was crap. i know you seem to be the man about this ****, but you don't need to cop an attitude with me and i don't appreciate it.
Sorry, it's a big pet peeve of mine.
Set the DMM to resistance - your DMM can measure resistance up to 10k-ohms, right?
Measure TPS on black and green wire.
Allow TPS to to go to full maximum travel.
If it's above 5.0k-ohms, it's suspect.
If it reads under 5.0k-ohms, the TPS cannot induce hesitations at WOT.
Anything over 6.0k-ohms is guaranteed it's bad.
Anything in between 5.0k and 6.0k-ohms might or might not trigger hesitations.
I detail this on my web page - click the link in my .sig
And that's how to tell your TPS is bad at WOT...
You can drop the vulgar swearing; you're not impressing anyone.
How you like it if I say "bitch"?
-Ted
Last edited by RETed; 11-25-04 at 09:15 AM.
11-25-04, 09:14 AM
#23
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Originally Posted by rexman13b
and if using the dmm is the right way, why didn't mazda dealships use one? they have special tools for that, and i'm sure they can determine whether or not a tps is bad better than a dmm. that's all i have to say about it, i'm not gonna argue with a guy 2000 miles away.
They have enough competence to read the FSM and follow instructions.
I'm sure there are others who can agree that the Mazda dealer is not the best place to take your RX-7 to.
That was a pretty weak argument.
-Ted
