2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Timing problem

Old Jun 11, 2011 | 12:31 PM
  #1  
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From: Weirton WV
Timing problem

I have a 1990 GXL/T2 swap. I'm having a problem getting rid of an all speed miss. I don't really notice it too much when accelerating briskly but it is very noticeable when trying to hold speed of accelerating slowly (like in traffic).
When I set the L1 plug to fire on the first mark, the T1 plug fires on almost the same mark and the T2 plug fires almost 90 degrees off. I grounded the test connector and the settings stay the same.
I know the trailing plugs don't add a lot to how well the engine runs but would being that far out of time cause the miss.
What would cause this?
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Old Jun 12, 2011 | 10:17 AM
  #2  
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Sounds normal to me. The rear rotor is about 90 degrees phased from the front.

Sounds like you have a vacuum leak or a TPS adjustment issue. Or both.
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Old Jun 13, 2011 | 08:35 AM
  #3  
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From: Weirton WV
Originally Posted by Aaron Cake
Sounds normal to me. The rear rotor is about 90 degrees phased from the front.

Sounds like you have a vacuum leak or a TPS adjustment issue. Or both.
Isn't the #2 trailing plug supposed to fire at the same time as the #1 trailing plug? Like the #1 & #2 leading plugs fire at the same time.
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Old Jun 13, 2011 | 09:27 AM
  #4  
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Originally Posted by arad99
Isn't the #2 trailing plug supposed to fire at the same time as the #1 trailing plug? Like the #1 & #2 leading plugs fire at the same time.
http://www.rotaryengineillustrated.c...ession-ex.html

heres a link, theres lots of ways to time a car.

l1 l2 are the same, it will fire waste spark.

t1 and t2 have the ability to fire independently.

also google 0 split timing, it is nice to know about.
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Old Jun 13, 2011 | 09:36 AM
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0 split will only happen if the engine is not idling down properly to set the timing. there should be a 15* split at idle.
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Old Jun 13, 2011 | 09:43 AM
  #6  
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From: bel air motel
the mazda factory service manual also recommends you drink from your pimp challis as you set base timing with a analog timing light.
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Old Jun 13, 2011 | 10:28 AM
  #7  
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From: Weirton WV
Originally Posted by Melgibson
http://www.rotaryengineillustrated.c...ession-ex.html

heres a link, theres lots of ways to time a car.

l1 l2 are the same, it will fire waste spark.

t1 and t2 have the ability to fire independently.

also google 0 split timing, it is nice to know about.
Thanks for the link. Very informative. This is my 5th 7 but I've never had to troubleshoot a timing issue. Usually just set L1 and you're good to go.
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Old Jun 13, 2011 | 11:55 AM
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If the CAS was stabbed correctly, there should be no reason for you to move it around afterwards. The timing light should be used to double check that you did it right, not as something to make adjustments with.
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Old Jun 13, 2011 | 01:42 PM
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From: FORT WORTH TEXAS
http://rx7.pw.cx/guides_manuals/coll...ystifying.html
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