Help me diagnose a rough idle

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audiocontr
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Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Help me diagnose a rough idle

Post by audiocontr »

I could use additional perspectives to figure out whats going on with my truck...

So ive noticed the idle sounds like a 1 cyl miss, especially while cold. It improves when it warms up, though the vibration is still there... just not as pronounced. Here are my observations and details:

I just installed the Pinz ssi ignition system.
Jim rebuilt my carburetors
it has WAY more power than it has ever had! Much earlier in the powercurve,,,
Timing is set 1 or 2 degress advanced beyond the pinz ssi instructions. Setting it on TDC just reduces power, no effect to idle
Idle speed is slower when cold. I do not use the choke now to start it. Idle speed increases once warm.
Smells a little "sweeter" than it did before the SSI
Ive checked the wires, and reseated all plugs. No change
Old plugs appeared pretty even across the board. Same with new plugs
Vacuum gauge is identical on front and rear carbs at idle

The exhaust couplers are the older style, and they have started popping. I need to replace with the flex piping. Would this cause it?

I adjusted the valves and checked compression last year. Everything was within spec. I can try again now if folks think its a good idea.

Produces grayish smoke at startup and hard throttle. Nothing excessive, nothing different than any of my other Pinz.

Any suggestions?
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
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pcolette
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Location: Southwest Wisconsin

Re: Help me diagnose a rough idle

Post by pcolette »

audiocontr wrote: The exhaust couplers are the older style, and they have started popping. I need to replace with the flex piping. Would this cause it?
That's definitely a possibility due to lack of sufficient back pressure. I would give that a try first. I remember a noticeable improvement on 2 Pinz's that had similar leakage/popping.

One other thought - have you adjusted the valves?
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
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audiocontr
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Posts: 1868
Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Re: Help me diagnose a rough idle

Post by audiocontr »

valves were done last year. Will do those when i do the exhaust
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
pinzinator
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Joined: Thu Jul 29, 2004 3:12 pm
Location: Indio, California

Re: Help me diagnose a rough idle

Post by pinzinator »

Advance the timing a few degrees, see if that makes a difference. Also, it the vacuum port plugged OK where the old distributor used to tap (above #2 cyl head)?
Buzz
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Location: Jacksonville, Fl.

Re: Help me diagnose a rough idle

Post by Buzz »

I would treat your gas for water. The seals on top of the gas tank were originally made of cork. If yours have not been changed, I can guarantee there is water in there. In my experience it can make the motor miss.
"It's as stupid and wonderful as owning a pet elephant."
1974 Pinzgauer 710M
1990 Puch G Wagon 230 GE
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audiocontr
United States of America
Posts: 1868
Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Re: Help me diagnose a rough idle

Post by audiocontr »

interesting suggestion! Will try
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
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