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Unread 06-17-2012, 09:49 AM   #1
Billyjoebob007
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Cylinder 1 miss fire issue :(

About once every couple weeks the check engine light comes on and with code reader it shows miss fire at no.1 cylinder. I dont detect anything that would be a miss fire like dieseling/sputtering/ ect. still runs nice and strong. Even after a complete tune up new everything it still occurs. What could possibly be causing this issue ?

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Unread 06-17-2012, 12:17 PM   #2
Billyjoebob007
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Also on the code reader i get a red led light for the emissions, after clearing the code out i get an amber light. So maybe somewhere the cylinder mis fire code is emission related ?
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Unread 06-17-2012, 12:28 PM   #3
JasonStebbins
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The three main causes of a misfire are a loss of spark, fuel/air ratio too far out of balance or loss of compression.

If you did a complete tune up I would suggest replacing the fuel injectors next. That is a common misfire problem. Did you replace the ignition coil/rotor as part of the tune up? When was the last time you replaced the upstream/downstream o2 sensors?
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Unread 06-17-2012, 01:30 PM   #4
Billyjoebob007
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Quote:
Originally Posted by JasonStebbins View Post
The three main causes of a misfire are a loss of spark, fuel/air ratio too far out of balance or loss of compression.

If you did a complete tune up I would suggest replacing the fuel injectors next. That is a common misfire problem. Did you replace the ignition coil/rotor as part of the tune up? When was the last time you replaced the upstream/downstream o2 sensors?
I did rebuild all the fuel injectors before the tune up, but before and after that i still got the code. I did install a new coil also. replaced o2 sensor last summer.
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Unread 06-17-2012, 01:35 PM   #5
JasonStebbins
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Hmm. The emissions will have nothing to do with the misfire. The evap system just recycles fuel vapors.

Have you ever replaced the fuel pump? Lack of fuel could cause a misfire, but it probably wouldn't be intermittent.
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Unread 06-17-2012, 04:12 PM   #6
gearheadnick
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You should do a compression test to rule out the possibility of loss of compression. Testing is free, just takes a bit of time.
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Unread 06-17-2012, 05:09 PM   #7
Billyjoebob007
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Quote:
Originally Posted by JasonStebbins View Post
Hmm. The emissions will have nothing to do with the misfire. The evap system just recycles fuel vapors.

Have you ever replaced the fuel pump? Lack of fuel could cause a misfire, but it probably wouldn't be intermittent.
Along the lines of a fuel issue, i have noticed for quite some time that when i turn a corner sharply i get a loss of power like fuel starvation. Its like if you have an old camero with a 4 barrel carb and the same thing occurs like the floats miss aligned causing fuel starvation when cornering sharply, but why would this occur in a fuel injected system ? fuel tank slosh preventing fuel pump from getting fuel ?
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Unread 06-17-2012, 05:21 PM   #8
JasonStebbins
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Quote:
Originally Posted by gearheadnick View Post
You should do a compression test to rule out the possibility of loss of compression. Testing is free, just takes a bit of time.
If he had low compression I don't think it would be an intermittent issue.

Quote:
Originally Posted by Billyjoebob007 View Post
Along the lines of a fuel issue, i have noticed for quite some time that when i turn a corner sharply i get a loss of power like fuel starvation. Its like if you have an old camero with a 4 barrel carb and the same thing occurs like the floats miss aligned causing fuel starvation when cornering sharply, but why would this occur in a fuel injected system ? fuel tank slosh preventing fuel pump from getting fuel ?
After reading this I am pretty certain you have a bad fuel pump. The same thing occurred in my Ford Escort. Whenever I turned a corner sharply the car would sputter and almost die if I had less than a quarter tank. Problem went away after I swapped in a new pump.

It's a pricey place to start, but that's the only thing you really haven't replaced. And you stated that you've replaced almost everything else that would cause a misfire.
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Unread 06-17-2012, 08:44 PM   #9
Billyjoebob007
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Quote:
Originally Posted by JasonStebbins View Post
If he had low compression I don't think it would be an intermittent issue.



After reading this I am pretty certain you have a bad fuel pump. The same thing occurred in my Ford Escort. Whenever I turned a corner sharply the car would sputter and almost die if I had less than a quarter tank. Problem went away after I swapped in a new pump.

It's a pricey place to start, but that's the only thing you really haven't replaced. And you stated that you've replaced almost everything else that would cause a misfire.
I usually keep a full tank or at least no more than 3/4 tank before refill. I have had my ZJ for exactly 2 years and its done the power/fuel loss cornering since i have had it, i would think if the fuel pump was bad it would have completely gone out by now, i dunno. I had a fuel injected Trans Am GTA that did the same thing.
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Unread 06-22-2012, 05:07 PM   #10
Billyjoebob007
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Now that i have posted this thread its happening more frequently, check engine light on again this afternoon. Misfire at cyl. 1
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Unread 06-22-2012, 06:41 PM   #11
JasonStebbins
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Does it actually misfire or is the ECU just throwing the code?
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Unread 06-22-2012, 07:14 PM   #12
edpmedic
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Quote:
Originally Posted by JasonStebbins View Post
Does it actually misfire or is the ECU just throwing the code?
That's what I was going to ask. Do you feel it miss? Also like mentioned above I would do a compression test dry and wet. Does it do it on a turn in both directions? I would also check the plug wire to see if it is secured and check the resistance.

Does the light go on at about the same amount of driven miles?
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Unread 06-22-2012, 09:00 PM   #13
Billyjoebob007
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Originally Posted by edpmedic View Post
That's what I was going to ask. Do you feel it miss? Also like mentioned above I would do a compression test dry and wet. Does it do it on a turn in both directions? I would also check the plug wire to see if it is secured and check the resistance.

Does the light go on at about the same amount of driven miles?
Dont feel or hear any miss at all before or after the engine light comes on. Plug wire is good, just replaced with new ones and same issue. As far as the fuel starvation issue, i think that it only does it on right hand turns.
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Unread 06-22-2012, 09:03 PM   #14
Billyjoebob007
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Quote:
Originally Posted by JasonStebbins View Post
Does it actually misfire or is the ECU just throwing the code?
At this point i think it may be the ecu, i dunno . When i can i will do a compression ck on no.1 cyl.
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Unread 06-26-2012, 02:34 PM   #15
GunnyA
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Silly question what kind of plugs are you using? I had the same issue with my 98zj after changing all kinds of valves and sensors I was one step away from changing the ECU. I was scanning the threads and ran across some bosch spark plug bashing. I had new bosch plugs in there so I never thought they would be the problem. They were gapped correctly and looked fine. I decided to change them out for a cheap pair of champions. Go figure it cleared it right up. Could have saved me a couple of hundred dollars in parts I didn't need.
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