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Discussion Starter · #1 ·
I’ve been having misfire issues for a while now. I thought it was because of a vacuum leak so I replaced all the cracked hoses but the misfire continued. One of the hoses I replaced is pretty kinked but still has air flow, I attached a photo of it (the one that bends downwards in photo) does anyone know if this could be causing a misfire?
138489
 

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Ask long as it’s not allowing air in from the atmosphere I wouldn’t think it would be the source of the misfire issue. It looks solid. Just to confirm this is a random misfire issue correct?
 

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Discussion Starter · #6 ·
Ask long as it’s not allowing air in from the atmosphere I wouldn’t think it would be the source of the misfire issue. It looks solid. Just to confirm this is a random misfire issue correct?
I believe it’s random. I fired it up one day and got misfire cyl 5 and random/multiple then I fired it up a couple days later and had a cyl 6 misfire and random/multiple those are the only codes I had other than a separate issue with my power steering
 

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Mr. Roo
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It might be that you used the wrong type of hose. Since vacuum is "sucky", it needs to be able to withstand being pulled closed. They are usually a lot beefier than positive pressure hoses. I would definitely bet that under heavier throttle (more vacuum) settings, that is pinching closed too much. However, I don't think that would cause a misfire code.
 

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I was checking some of your other posts, you noticed at some point the trac control light and the ABS light were blinking. How’s your battery and alternator? Not having enough power to your coils will definitely cause a misfire. Do you notice rev limiting at lower than normal RPM? I also saw you mentioned cylinder 6’s spark plug wire being too short, has that been fixed?
 

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Discussion Starter · #10 ·
Have you checked the connectors at the coils and if there is any oil in the valley?
I replaced all the connectors and just put a new valve cover gasket in and cleaned everything aswell as replaced the coils and spark plugs

I was checking some of your other posts, you noticed at some point the trac control light and the ABS light were blinking. How’s your battery and alternator? Not having enough power to your coils will definitely cause a misfire. Do you notice rev limiting at lower than normal RPM? I also saw you mentioned cylinder 6’s spark plug wire being too short, has that been fixed?
My battery does keep dying but I figured it was because I left my hood open for a while and I heard that can cause the security system to drain the battery, the battery voltage is also still 13+ volts at idle. I’ll test my alternator though seems like that could be an issue, just seems weird too me considering the alternator was working perfectly well before I parked it to do maintenance

The abs light isn’t flashing anymore just the trac light flashes from the misfire. The car idles at normal rpms but when I took it for a test drive it did seem like there was some rev limiting if I remember correctly.

I fixed the spark plug wire issue I just put the old wires back in because they seemed to be in good shape

I’ll post an update tomorrow after I test the alternator and check again for rev limiting
 

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Discussion Starter · #11 ·
Another thing too note is that my rpms have been sitting a bit high at idle until the engine warms up. I had the idle issue before I got the misfire where sometimes it’d even sit at 1300 rpms, it went away for a while but recently I’ve noticed it sitting at 1100.
 

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Check the connection at the ignitor. Have you checked compression? Check your APP and TPS sensors. Have you checked the cam and crank sensor? Also the reluctor wheel on the crank?
 

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If you added any dielectric grease have you tried cleaning the ends of the spark plug wires where the metal contacts are?

I’ve recently replaced my ignition coil connectors and spark plug wires then had a misfire.Took it back apart cleaned all the connections thoroughly with a cue tip and some alcohol and misfire went away.

You can also test your spark plug wires and ignition coils with a multimeter when you have them off.
 

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Discussion Starter · #14 ·
If you added any dielectric grease have you tried cleaning the ends of the spark plug wires where the metal contacts are?

I’ve recently replaced my ignition coil connectors and spark plug wires then had a misfire.Took it back apart cleaned all the connections thoroughly with a cue tip and some alcohol and misfire went away.

You can also test your spark plug wires and ignition coils with a multimeter when you have them off.
I did add dielectric grease so I’ll give this a try, I just sprayed them down with electrical contact cleaner first so the cue tip should clean it better. Is it bad to add dielectric grease? I just put a small amount on since I thought that was correct
 

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I did add dielectric grease so I’ll give this a try, I just sprayed them down with electrical contact cleaner first so the cue tip should clean it better. Is it bad to add dielectric grease? I just put a small amount on since I thought that was correct
No it’s not bad, I just added too much and I’m guessing some rubbed onto the metal contacts when I installed them. Added some again after I cleaned them but much less and only around the rim of the seal.
 

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Discussion Starter · #16 ·
My alternator isn’t the issue and my revs aren’t being limited, I cleaned all the plug wires but I still got a pending code for random/multiple misfire and it seemed like it was missing. The stepper motor started clicking a bunch could this be contributing to my idle issues since it was idling at about 1200 for the first few minutes of it running but it slowly jumped down to 1000 in park
 

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Discussion Starter · #17 ·
Check the connection at the ignitor. Have you checked compression? Check your APP and TPS sensors. Have you checked the cam and crank sensor? Also the reluctor wheel on the crank?
I haven’t checked compression I was planning on doing that after troubleshooting some more. I’m not getting codes for any of those sensors, and other than new connectors on the TPS and APP I haven’t even touched any of them and the car was working great before so I’m not sure what would cause any of them to fail. I cleaned the igniter and reconnected it but it was connected great before and wasn’t really dirty before I cleaned it with electrical connector cleaner. Shouldn’t I get separate fault codes if there were issues with these sensors?
 

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Discussion Starter · #18 ·
Also my MAF is reading around 6 grams/sec I’m not sure if this is normal or not. my short term fuel trim is in the negatives too, I assume this is because of the misfire but i don’t know for certain.
 

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Discussion Starter · #19 ·
I ran it again and my maf read at about 4.5 g/s instead this time. It was idling lower too though so I don’t know if it’s because of that or if my MAF is having issues
 

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I ran it again and my maf read at about 4.5 g/s instead this time. It was idling lower too though so I don’t know if it’s because of that or if my MAF is having issues
If that is at 4.5 voltage. It is high. Should be around 3 volts. There is a procedure in the factory manual you can do to check all of this stuff. Just download a copy and look it up.
 
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