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914World.com _ 914World Garage _ Another small idle problem - any help?
Posted by: StarBear Oct 17 2019, 05:14 PM
Lots of idle problem threads in the Garage, but I think this is a new one not previously covered:
1. 1974 1.8 L-Jet; regular points/condenser and dual port vaccuum cannister.
2. Runs flawlessly and reliably; idles about 1000 rpm at startup
3. Just recently, when at a stop, the idle drops back to only 1200 rpm instead of 1000.
4. If I engage the clutch just a tad the idle goes back down to 1000 and stays there (until the next stop). 
I've checked the throttle spring and such. Maybe something with the vaccuum canister or some other little demon hiding somewhere?
In advance, thanks for your knowledge and insights!
Posted by: jcd914 Oct 17 2019, 07:06 PM
I would check that the mechanical advance mechanism in the distributor moves freely.
And lube it while you are checking it.
It takes a drop or two of light oil on the felt pad in the distributor shaft under the rotor.
It is an often missed maintenance item and the the advance sticks.
Jim
Posted by: Mikey914 Oct 17 2019, 07:14 PM
2nd that
Posted by: rjames Oct 17 2019, 09:21 PM
My 2.0 just started doing this. I think I’ve traced it to a bad decel valve that isn’t completely closing since disconnecting seems to correct the issue and allow the idle to drop to 800-900 rpms.
Posted by: Olympic 914 Oct 18 2019, 06:56 AM
have to check that...
My idle is always 1100- 1200. just thought it was the nature of the beast.
I've gotten used to it.
Posted by: StarBear Oct 18 2019, 02:17 PM
I would check that the mechanical advance mechanism in the distributor moves freely.
And lube it while you are checking it.
It takes a drop or two of light oil on the felt pad in the distributor shaft under the rotor.
It is an often missed maintenance item and the the advance sticks.
Jim
Will try it tomorrow and let you know. Thanks!!
Posted by: StarBear Oct 18 2019, 02:19 PM
My 2.0 just started doing this. I think I’ve traced it to a bad decel valve that isn’t completely closing since disconnecting seems to correct the issue and allow the idle to drop to 800-900 rpms.
Hmmm; thought about that but other posts seem think the valve works only on startup or something. Do you knowof any way to check or clean it (just to be sure)?
I appreciate your response and help.
Posted by: StarBear Oct 18 2019, 02:22 PM
have to check that...
My idle is always 1100- 1200. just thought it was the nature of the beast.
I've gotten used to it.
It's my OCD....
And Virgo and (retired) engineer. I'm in long-term recovery... 
Posted by: rjames Oct 18 2019, 03:43 PM
My 2.0 just started doing this. I think I’ve traced it to a bad decel valve that isn’t completely closing since disconnecting seems to correct the issue and allow the idle to drop to 800-900 rpms.
Hmmm; thought about that but other posts seem think the valve works only on startup or something. Do you knowof any way to check or clean it (just to be sure)?
I appreciate your response and help.
Easy: Just block off / plug the connections to/from it (take it out of the loop).
Posted by: StarBear Oct 19 2019, 01:49 PM
I would check that the mechanical advance mechanism in the distributor moves freely.
And lube it while you are checking it.
It takes a drop or two of light oil on the felt pad in the distributor shaft under the rotor.
It is an often missed maintenance item and the the advance sticks.
Jim
Yep, that did the trick! Took a few miles and engine warmup on a great fall afternoon. Again running like a champ!
Thanks ever so much, Jim. I love 914world (and the people in it...)
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