KA-T Misfires and runs rich when cold
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KA-T Misfires and runs rich when cold
first off yes i searched. found alot of stuff but nothing was useful. but heres the problem: one day I go to start my car to go to work and it revs to 1,6-1,800 rpms settles to 8-900rpms and runs super rich and misfires. it smokes an reeks of fuel. as soon as i let it get to normal operating temp poof. runs fine. no issues at all. drives fine, idles fine, boost/pulls fine. this started a few weeks ago and has been doing it ever since. sometimes when I start it up cold it revs all the way to 2,000-2,200 rpms for 20 seconds or so then it settles back to 8-900rpms.. I havent messed with anything or changed anything. just started doing it one morning and has been doing it ever since. my S14 has been boosted for 17,000 miles and never did this before. ill give a little more info on my setup incase it helps:
S14 KA. 172,xxx
SR T-25 At 7psi
FMIC
HKS SQQV
3" downpipe
3" exhaust
BKR6E plugs
Enthalpy Tuned ECU
any input will help. thanks.
S14 KA. 172,xxx
SR T-25 At 7psi
FMIC
HKS SQQV
3" downpipe
3" exhaust
BKR6E plugs
Enthalpy Tuned ECU
any input will help. thanks.
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KA-T.
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Coolant Temperature Sensor & Throttle Position Sensor, you should be running a heat range 7 plug too iirc.
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a bad coolant temp sensor and throttle position sensor would cause it to run like that? im not questioning your knowledge or anything i just didnt know that those would cause that. interesting...
and should i run BKR7E's or BKR7EIX's?
and should i run BKR7E's or BKR7EIX's?
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KA-T.
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The coolant temperature sensor tells the ECU how much fuel to put into the car. If it's not working correctly the ecu thinks the car is cold and floods the cylinders. TPS not being calibrated correctly will make the ECU think that the throttle isn't being depressed when it really is or vice versa or it could even make the car think you are pressing the throttle harder than you really are. The ECU relies on sensors (maf, tps, cts, o2, iat, iacv, aiacv etc.)to tell it what the car is doing. lol
As far as plugs go, the 7e's are copper tipped, and the 7eix's are iridium tipped and pre-gapped perfectly. Iridium will last much longer than copper, so basically throw them in and forget about it (providing your tune is spot on). Do not get the 7eix-11's as they are gapped super high. Has this thing been on a dyno? Mail order tunes are great, but to really get an idea of what's going on you need to run it in ideal conditions with a wideband and log stuff. Changing something as minor as a catalytic converter to a test pipe and not re-checking the tune cost me a $4000 motor.
As far as plugs go, the 7e's are copper tipped, and the 7eix's are iridium tipped and pre-gapped perfectly. Iridium will last much longer than copper, so basically throw them in and forget about it (providing your tune is spot on). Do not get the 7eix-11's as they are gapped super high. Has this thing been on a dyno? Mail order tunes are great, but to really get an idea of what's going on you need to run it in ideal conditions with a wideband and log stuff. Changing something as minor as a catalytic converter to a test pipe and not re-checking the tune cost me a $4000 motor.
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The coolant temperature sensor tells the ECU how much fuel to put into the car. If it's not working correctly the ecu thinks the car is cold and floods the cylinders. TPS not being calibrated correctly will make the ECU think that the throttle isn't being depressed when it really is or vice versa or it could even make the car think you are pressing the throttle harder than you really are. The ECU relies on sensors (maf, tps, cts, o2, iat, iacv, aiacv etc.)to tell it what the car is doing. lol
As far as plugs go, the 7e's are copper tipped, and the 7eix's are iridium tipped and pre-gapped perfectly. Iridium will last much longer than copper, so basically throw them in and forget about it (providing your tune is spot on). Do not get the 7eix-11's as they are gapped super high. Has this thing been on a dyno? Mail order tunes are great, but to really get an idea of what's going on you need to run it in ideal conditions with a wideband and log stuff. Changing something as minor as a catalytic converter to a test pipe and not re-checking the tune cost me a $4000 motor.
As far as plugs go, the 7e's are copper tipped, and the 7eix's are iridium tipped and pre-gapped perfectly. Iridium will last much longer than copper, so basically throw them in and forget about it (providing your tune is spot on). Do not get the 7eix-11's as they are gapped super high. Has this thing been on a dyno? Mail order tunes are great, but to really get an idea of what's going on you need to run it in ideal conditions with a wideband and log stuff. Changing something as minor as a catalytic converter to a test pipe and not re-checking the tune cost me a $4000 motor.
aaaaand so i replaced the Coolant temp sensor and Got BKR7EIX plugs. on the drive home the car drove freaking AMAZING. revved smoothly. idled smoothly, and it pulled so much harder and held power all the way to redline, no breaking up or hesitation at all. my car hasnt ran that good in awhile.. BUT when i started the car up this morning... it still did the same thing.. i havent replaced the TPS yet though.. dont know if it'll change anything..
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Had this problem on a few cars. With a bad coolant temp sensor, the ecu reads the outside temps as 30 degrees Farhenite. It runs rich trying to compensate and get the engine warmed up. If your TPS was bad, then you would have either a bouncy idle and you wouldn't be able to rev very high. If its running rich still on a cold start after you ajust your TPS, check the O2 sensor. If its a 4 wire...there are 2 wires that are a heat circuit to help heat it up, the wiring could be bad.
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Im going with coolant temp sensor as well...
i know this is completely irrelevant, but i had a 96 mazda mx6 v6 swapped it over to klze and my temp sensor wire got snipped....I got the exact same issues your having, and the rev limiter changed to 5500. rewired it, ran great, revved to 8k.
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i know this is completely irrelevant, but i had a 96 mazda mx6 v6 swapped it over to klze and my temp sensor wire got snipped....I got the exact same issues your having, and the rev limiter changed to 5500. rewired it, ran great, revved to 8k.
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^ive already replaced the coolant temp sensor though.. read my post a couple up. im starting to wonder if its a 02 sensor.. ill replace the TPS and 02 sensor and see what happens.
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You don't have to replace the tps, just adjust the voltage to factory spec. Rom tunes are load based.
