Idles high after a hard run

[Richard Petersen]

Re: Idles high after a hard run

The last time I ever faced a high smooth idle like yours, was on a car that had a throttle DASH POT. It's purpose is to give a slow closing of the throttle plate the last 1500 to 2000 rpms down to idle. If your carb or linkage has one any where, including one INSIDE the carburator, go after it. Check with Volvo if they have one. DASHPOTS can get dust in their very tiny venturies and do what you have. They look just like any vacum operated valve.

 

[Johnnydeep]

Re: Idles high after a hard run

I didn't mean to turn this into a drug out slamfest, Don I was kind of hopeing you would chime in on this problem, I am pretty sure its probably an air leak at this point I will hit it with carb cleaner( non-flammable) when shes hotand see, although the dist could have some wear. I tend to stay up on things as we put a considerable number of hours on our boat, almost 600 in 2 years, wich brings the engine in at about 750 hrs.<br /> with the heat exchanger problems on top of this I almost would like to swap to a v-8 as a low hour volvo 8 is not really that hard to find, Unfortunatly I have the 275 drive... and we are planning on moving up to a 280 carver or a 300 weekender so I don't want to get into a huge project on a boat that I will only have for another year!.. And no this is not the first time I have laid eyes on an engine and I do as much of the work myself as I possibly can.

 

[Don S]

Re: Idles high after a hard run

To tell you the truth, I'm with a couple of the earlier posts about the vacuum leak or advance problems. Did you put a vacuum gauge on it and see what was happening? No since squirting liquid everywhere if the vacuum reading is ok. You also might check for wear on the timing belt. The teeth on that belt should be as wide as the gaps between them. Worn belt, rusty weights, vacuum leaks, leaky carb......lots of things could cause the problem. Might even be a combination of a couple.

 

[Johnnydeep]

Re: Idles high after a hard run

I kind of agree on that point as the timing belt has a couple hundred hours on it now, and I have been lubing the dist on a regular basis(oilchange every 50hrs), I also suffer from an erratic idle(bumps 50 rpm or so) and a heavy float in the carb( solexs are cheap to rebuild) I guess I will stick ro my plan to do a major service after new years and if that does not clear it up I will dig into that expensive little bosch distributer, Volvos are great engines...just expensive(but well made) parts

 

[Don S]

Re: Idles high after a hard run

Don't be afraid to pull the point plate out of the distributor and look for rust/corrosion on the weights.

 

[Johnnydeep]

Re: Idles high after a hard run

BINGO>>>>just had an epiphany, When I first got the boat I left the strainer lid loose and hosed the distributer with saltwater...Have paid the price for that oversight several times with point/cap/rotor etc... Had the points plate off this summer and noticed some rust on the weights, I hosed it with wd40 and did not think much of it...key words, didn't think(lack of experience)...any ideas on rebuilding that expensive little bugger? should have done it when I found it wet.. I know my starter/alternator guy in Kent does not do distributers...

 

[trog100]

Re: Idles high after a hard run

hmm.. well we aint exactly learned much here have we.. except that the boat with the "problem" has a few other problems.. like worn cambelt.. iffy distributor.. iffy heat-exchanger.. iffy carb.. and is in desperate need of "major service"..<br /><br />yep.. as don tends to imply.. could be almost anything.. he he he..<br /><br />err.. can one buy none flammable carb cleaner.. <br /><br />mery chistmas dudes..<br /><br />trog100

 

[Johnnydeep]

Re: Idles high after a hard run

Deperate... I think not! Iffy...well I am here!! Thanks for the help Don!