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Author Topic: Engine Misfiring at Idle
Greg Kimble Verified Driver
Member

Region: CFR
Car #: 81
Year : 1994
Posts: 86
Status: Offline
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My 94 1.8L is misfiring at idle. It seems to go away with the application of the throttle. The check engine light does not come on at any time. The mis seems less noticable when the engine is cold vs when it is at operating temperature. This motor has about 80k road miles on it. Prior to using it for a drivers school last month, we changed plugs, wires, all seals and gaskets and the timing belt. Not sure where to start looking, dirty injectors? O2 sensor? Trying to confirm/set timing with it missing is impossible. Any suggestions are appreciated.

Thanks

Greg

Chris Windsor Verified Driver Made Donation to Website Series Champ
windsorcustoms.com

Region: WDCR,
Car #: 38
Year : 1991
Posts: 841
Status: Offline
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Compression and leak down to start, be sure the mechanicals are good

--------------------
2011 Season schedule coming soon
Support, sales, repair or rental
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Champ
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Posts: 18
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Greg,
It sounds like the timing belt wasn't installed correctly or that the timing wasn't set properly. Given that it idles better after it is warm says to me the timing it retarded to far at idle and as it warms up naturally ignites sooner than when cold. When you apply throttle your timing gets advanced, but probably not far enough for maximum power. You should see a significant increase in power after you adjust the timing. A simple re-inspection of the timing might solve your problem.

Do the simple things first.

Good luck

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'99 Miata (1.8l) purchased and dedicated to SM in '09

johnh23
Member

Region: central nj
Car #: under construction
Year : 1996
Posts: 42
Status: Offline
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like chris said check leakdown first then look at injectors it seems like you covered everything else

dsrgr Verified Driver Made Donation to Website
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Region: Las Vegas
Car #: 2
Year : 92
Posts: 156
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Make sure your timing mark isn't off from TDC.
After a slow weekend, checked mine with a dial indicator and found it 6 degrees off....

Greg Kimble Verified Driver
Member

Region: CFR
Car #: 81
Year : 1994
Posts: 86
Status: Offline
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Here is some more info, I went out to start looking into the problem and double check the timing. When I put in the jumper wire I got a code 16 from the computer. I believe that to be an EGR code. Can anyone shed light on what I am looking for, the description seems a little vague.

Thanks

Greg

   

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