351 PCM runs well but won't idle
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=47550
Printed Date: April-28-2024 at 7:03pm
Topic: 351 PCM runs well but won't idle
Posted By: schmisw
Subject: 351 PCM runs well but won't idle
Date Posted: June-04-2019 at 10:52pm
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I just purchased a 1985 SN 2001 w 351 PCM w/ 4 barrel holley. - I had it running 2 different days in my drive; and then took it to the water a different day- started great - ran 25-32 mph very well; at that point engine died when I went to neutral - seemed to be running rich; couldn't' get re-started so we waited for an hour or so (skied on buddy's boat); came back started up and ran for another 20 minutes pretty well; then from here on out I couldn't idle any more - it would die right away; only by luck did I once get it shifted quickly enough from start to engage forward to get it back to dock; I couldn't keep it running to load it; Is this related to dirt on the needle/carb? or poor fuel? aka - should I only be running non-ethanol? Previous owner said he ran wasn't picky about what he ran. Being a new to me boat; is best step to flush all the fuel, run non-ethanol only, replace plugs, have someone tune the engine? replace all fuids? what should floats be? What other steps to consider? what items don't matter? |
Replies:
Posted By: MourningWood
Date Posted: June-05-2019 at 1:03am
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Good friend experienced exact same symptoms w/ his '83. Replaced carb, freshened ignition system...still same. I detected vacuum leak. removed intake manifold and replaced gaskets/seals. Voila. ------------- 1994 Ski Nautique "Riot" 1964 Dunphy X-55 "One 'N Dun" 'I measured twice, cut three times, and it's still too short!" |
Posted By: rebel skier
Date Posted: June-05-2019 at 10:06am
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Do you have the old fram fuel filter in the long black metal cup? You can go to skidim and see what it looks like. I wonder when it was last replaced. It starts to disintegrate over time. Replace that and add some sea foam before doing all you said about the fuel system. Look at the clear tube from the fuel pump. Make sure it is not dumping excess fuel into the carb and chocking off your idle. Run with the flame arrestor off, and watch and see what is occuring at the carb. Better people than me will come give you more tips. Nothing better than an 85 Ski Nautique! When was the last carb rebuilt? ------------- Hotty Toddy lets go skiing! |
Posted By: rebel skier
Date Posted: June-05-2019 at 10:08am
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Just saw yours in the diary section. Damn nice looking boat. Looks well cared for too. Get some info from the previous owner on the last filter replacement / carb rebuild ------------- Hotty Toddy lets go skiing! |
Posted By: sayoung68
Date Posted: June-05-2019 at 12:56pm
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I am having the exact same problem with my 80 SN with same set up. Just replaced plugs and fuel filter to no avail. The idle issue seems to happen after the motor has warmed up. I followed advice to look into the carb while idling to see if it was spitting excess fuel. No fuel visible. I will monitor this post with interest. Fortunately I have my 04 Nautique 226 here too  ------------- 80 Ski Nautique 04 226 Sport |
Posted By: KENO
Date Posted: June-05-2019 at 1:26pm
One other leak to look for would be the gasket between the manifold and the carburetor spacer and also the gasket between the spacer and the carburetor Maybe you'll find something there and it's a lot easier to cure than taking the manifold off  Check the link below for some info http://www.correctcraftfan.com/forum/forum_posts.asp?TID=43335&title=stalling-at-idle" rel="nofollow - link |
MourningWood wrote:Posted By: shierh
Date Posted: June-05-2019 at 1:26pm
| rebuild the carburetor. |
Posted By: KENO
Date Posted: June-05-2019 at 1:33pm
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Whatever you decide to do, the gaskets in the link work real good at sealing both sides of the spacer. If you're gonna take the carburetor off to rebuild or whatever, these gaskets are pretty much an item to replace if you don't know how old the ones that are in place are https://www.skidim.com/prodinfo.asp?number=RM0054B" rel="nofollow - link And don't forget to think about the ignition system as a possible cause. |