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-   -   cold start problem (https://www.rx7club.com/1st-generation-specific-1979-1985-18/cold-start-problem-970978/)

Colbskee 09-26-11 12:38 PM

cold start problem
 
When i start my car after it has been sitting over night or for about 5-6 hours, it starts great, idles good for about 30 seconds, then sounds like it's running on one rotor. After i give it some gas and let it warm up for about another minute or two and start driving, it sputters and wants to die, then suddenly starts running fine. only does this when i FIRST start it and drive it. no other times. I seafoamed it today and bought new plug wires, if that doesnt make a difference, i'll post in here.

Please note: Plugs are NGK with about 2 weeks driving on them, and plug wires are also NGK and i put them in this morning. Checked out cap and rotor and they dont seem to bad at all.

DarkDrakeX 09-26-11 02:11 PM

It could possibly be a stuck spring on one of the seals. essentially a collapsed apex seal till some gas/oil gets in there and loosens it up. Do a ghetto compression test when its cold and hasnt been started when u assume its going to happen (pull lower spark plug on 1 rotor turn by hand and listen for 3 poofs) do same for the other rotor.

7aull 09-27-11 03:11 AM

yeah - my SA does the same thing on cold-starts - would LOVE to know what's up. always fine once it warms up, never a problem the rest of the day's start/stops.
weird...

Stu Aull
80GS
Alaska

Colbskee 09-27-11 11:49 AM


Originally Posted by DarkDrakeX (Post 10801347)
It could possibly be a stuck spring on one of the seals. essentially a collapsed apex seal till some gas/oil gets in there and loosens it up. Do a ghetto compression test when its cold and hasnt been started when u assume its going to happen (pull lower spark plug on 1 rotor turn by hand and listen for 3 poofs) do same for the other rotor.

Will try that today before i go anywhere. If it is a stuck spring, how do i repair that without pulling the motor apart?

Sgt Fox 09-27-11 07:04 PM

Take the plugs out and have a look. I've had new plugs foul like that.

Colbskee 09-28-11 12:04 AM

well.. It seem's that the spark plug wires made a difference. Although, the leading plugs looked to be a little white. That means it's running lean right? And they should be a chocolate brown?

t_g_farrell 09-28-11 07:22 AM

My SA does the same thing if it has been sitting for more than a week without
starting it. My theory is one rotor gets washed with a pure gas mix and doesn't
seal until the MOP gets enough oil up into the carb to mix in. I know its not an
ignition or wire issue abd it only happens in the above situation. As longs as I drive
or start it once a week or more it never happens.

Colbskee 09-28-11 10:30 AM


Originally Posted by t_g_farrell (Post 10804068)
My SA does the same thing if it has been sitting for more than a week without
starting it. My theory is one rotor gets washed with a pure gas mix and doesn't
seal until the MOP gets enough oil up into the carb to mix in. I know its not an
ignition or wire issue abd it only happens in the above situation. As longs as I drive
or start it once a week or more it never happens.

I premix my gas so i dont see that being the problem with my car. it still does it ever so slightly, so i think cap and rotor are next on the list of things to buy.


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