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  #1  
Old July 20th, 2010, 15:35
91blackbox 91blackbox is offline
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still cutting out

i was piggy backed on another thread but figured i would start another..

issue: ok as i'm driving she will cut in and out.. but only after she warms up....

changed: fuel filter , tps, cps<crank>, cap rotor, plugs, wires, map ...

also the cat was changed a while back so i could pass smog..

any ideas...

i'm not convinced its a fuel issue for the sheer fact that sometimes when she cuts out and kicks back in she backfires....

no problems starting... idles ok.. has alittle shake but nothing extreme...

i did notice some play in the dizzy shaft.. but i have heard play is ok.. its up and down about an 1/8 and side to side about 1/8.....

but again i'm also not convinced its the dizzy cause she runs fine at idle...

I'M BAFFLED!!!!
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  #2  
Old July 20th, 2010, 18:26
joe_peters joe_peters is offline
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Re: still cutting out

Up down, Ok, that is normal. Side to side is NOT Ok. You have a shaft made to spin on its own center axis and it is able to wobble side to side.

When its doing its HULA DANCE a cylinder doesn't get its injector firing pulse--where does the compressed air (minus the fuel it didn't get) go? It is pumped out of course, into the exhaust manifold, where the oxygen mixes with residual hydrocarbons that exist normally in the exhaust (that nasty HC they measure at the emissions testing stations). So, now you have HC, o2, and heated exhaust--ignition. What is the main cause of backfiring? When o2 is getting into the exhaust and igniting with the unburned hydrocarbons.

Any of that sound vaguely familiar?

Good luck.
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  #3  
Old July 20th, 2010, 18:29
JJacobs JJacobs is offline
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Re: still cutting out

Give the rotor a twist, does it turn back and forth more than a couple degrees?
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  #4  
Old July 20th, 2010, 19:38
91blackbox 91blackbox is offline
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Re: still cutting out

Quote:
Originally Posted by JJacobs View Post
Give the rotor a twist, does it turn back and forth more than a couple degrees?

it doesnt move very far... just a bit not even a 1/16
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  #5  
Old July 20th, 2010, 19:39
91blackbox 91blackbox is offline
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Re: still cutting out

Quote:
Originally Posted by joe_peters View Post
Up down, Ok, that is normal. Side to side is NOT Ok. You have a shaft made to spin on its own center axis and it is able to wobble side to side.

When its doing its HULA DANCE a cylinder doesn't get its injector firing pulse--where does the compressed air (minus the fuel it didn't get) go? It is pumped out of course, into the exhaust manifold, where the oxygen mixes with residual hydrocarbons that exist normally in the exhaust (that nasty HC they measure at the emissions testing stations). So, now you have HC, o2, and heated exhaust--ignition. What is the main cause of backfiring? When o2 is getting into the exhaust and igniting with the unburned hydrocarbons.

Any of that sound vaguely familiar?

Good luck.

some but not alot.. it makes sense though
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  #6  
Old July 26th, 2010, 17:15
91blackbox 91blackbox is offline
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Re: still cutting out

btt...

replaced dizzy... no change???
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  #7  
Old July 26th, 2010, 17:44
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cruiser54 cruiser54 is offline
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Re: still cutting out

Have you ever refreshed all your engine bay grounds? Joe probably has a pre-written response on ground refreshing that he could insert into a post. I woulda done it but don't know how. He's more computer savvy than I am, but we both share an emphasis on refreshing grounds as we worked on these things when they were new and the insufficient grounds were a problem back then. I'm sure they haven't improved with age nearly as much as Joe and I have.............
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  #8  
Old July 27th, 2010, 15:23
91blackbox 91blackbox is offline
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Re: still cutting out

i went thru and checked my grounds and they all look good...
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  #9  
Old July 27th, 2010, 15:50
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B.RAIDER B.RAIDER is offline
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Re: still cutting out

Quote:
Originally Posted by 91blackbox View Post
i went thru and checked my grounds and they all look good...
Did you use a DVM to check the grounds to verify this?
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