351W starting problems
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=48293
Printed Date: November-26-2024 at 7:27pm
Topic: 351W starting problems
Posted By: Wilhelm Hertzog
Subject: 351W starting problems
Date Posted: December-29-2019 at 5:52am
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Following my https://correctcraftfan.com/forum/forum_posts.asp?TID=47357" rel="nofollow - fresh water cooling conversion (and in addition to the overheating issue I'm having) my motor also started having trouble starting when it reached operating temperature. The motor would start up fine when cold, but when it reached operating temperature, the starter really struggled to turn the motor over (sounds like the battery is dead, despite it being fully charged), and would often fail to start. When the motor cooled down, it would start up easily again. Last time out on the lake, the motor died when I was coming in to dock (i.e. at idle speed), and now does not want to start at all. The motor turns over (not as freely as perhaps I recall it doing before the recent rebuild and FWC conversion), but just does not start. I moved the distributor rotor around a bit to see if changing ignition timing does anything, but no luck. I pulled the no. 1 spark plug and checked for spark, but could not see anything. This causes me to suspect there is a bad ground somewhere in the ignition system or a faulty part in my distributor. Spark plugs and spark plug leads are new. Any advice as to where to start looking will be hugely appreciated! ------------- 1982 Ski Nautique PCM351W RR II Velvet Drive 10-17-003 1:1 II PerfectPass Stargazer Do not go gentle into that good night. Rage, rage against the dying of the light. |
Replies:
Posted By: MrMcD
Date Posted: December-29-2019 at 2:35pm
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When you switched back to fresh water cooling did you change your thermostat also? Fresh water engines ran at 140 before fuel injection came along while closed cooling systems ran higher temps, 180 maybe. Your starting issue sounds like a new separate issue. Was there damage done when it overheated? I would start with the basics since you know #1 is not sparking. Verify your coil is getting power and then verify your points are set properly and in good shape. Can you verify your battery grounds are clean and tight with not corroded. Would need to check at the battery and at the other end of your cables. The only way to verify a good connection is to remove, clean and reinstall. A little vasoline or dielectric grease will keep any corrosion from starting for the life of your battery. Just a thin film of the vasoline wiped over the battery terminal and the cable ends before connecting eliminates this problem. I have no idea why this actually works but it does. A mechanic told me to do this 35 years ago and many others have verified this trick to me. With a thin film it will look a little shiny but leave no mess to wipe off. Starter having trouble turning the engine over after you had overheat issues, you might pull all 8 plugs and try to turn it over. You may find water sprays out of one or more holes. That would be another issue to track down. Starting issues when hot are sometimes tune up related, timing not set correctly. It could also be the starter is just struggling to spin due to age or rust inside but that is normally true when cold and hot. Your issue is a tough one, runs good then loses spark and the starter will not spin properly then you add in previous overheats to the equation. I don't know of one simple answer that addresses all of those situations. You are probably looking at multiple causes unless water got in cylinder #1, water fouled the spark plug and hydro locked the piston so it was compressing water not air and the starter could not turn it? The thing that goes against this guess would be the fact it starts again when it cools off. If water is in a cylinder it stays there so you will not start hot or cold once water gets in. Bad coils can work when cold and stop working when hot, this has happened to many people over the years. I have seen starters work when cold but slow down when hot, I think they called this heat soak and some, even the factory fixed this issue with heat shields, saw this on Chevy V8 engines. ------------- |
Posted By: Wilhelm Hertzog
Date Posted: December-29-2019 at 6:01pm
Apologies about the confusion: I converted from raw water cooling to fresh water cooling/closed cooling - not the other way around. Thanks for the pointers, I'll be troubleshooting away... ------------- 1982 Ski Nautique PCM351W RR II Velvet Drive 10-17-003 1:1 II PerfectPass Stargazer Do not go gentle into that good night. Rage, rage against the dying of the light. |
MrMcD wrote:Posted By: GottaSki
Date Posted: December-29-2019 at 6:25pm
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Slow hot cranking you describe is too much initial advance ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: KENO
Date Posted: December-29-2019 at 7:29pm
Couple of things needing some clarifying here, first one fresh water cooling is the same thing as closed cooling. and then there's raw water cooling that most people on CCF are accustomed to I know you understand that Wilhelm, but somebody else doesn't  Second, there aren't any points to look at in your HEI distributor, I figure you know that too. You can find troubleshooting procedures for your HEI system in various places on the internet with direction on testing the ignition coil and the pickup coil in the distributor. The module takes a specialized tester but you can eliminate everything else and narrow things down to a bad module if everything else is good. I don't know what you mean by saying you moved the rotor Wilhelm. Did you loosen the hold down clamp and rotate the distributor to change the timing? Or maybe just wiggle the rotor to see that the advance works? Like GottaSki said, a slow hot crank sounds like your initial timing is too far advanced. It can start easy when cold and struggle to start when warm. You could also have a weak starter , but knowing where your timing is set would be a big help So..................What do you have your timing set at? |
Posted By: KENO
Date Posted: December-29-2019 at 8:43pm
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If you click on the link and go to Topic 3 you'll have the DUI troubleshooting instructions for a no spark condition The wire colors should be the same and the specs for the coil and magnetic pickup should all be the same or real close also. and the procedure is the same even though yours isn't a DUI version of the distributor. Yours and the DUI are both copies of the original GM HEI .from the 70's The modules are probably different internally but any GM HEI module with the same terminal arrangement will work in them to get you running again if you have a module problem, some perform better than others https://performancedistributors.com/professional-tips/" rel="nofollow - link |
Posted By: MrMcD
Date Posted: December-30-2019 at 4:50am
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Advanced timing can certainly cause hard hot starts no question but advanced timing will not affect spark quality. Did not see the previous post about his engine upgrade. An 82 would have a standard distributor normally. A DUI is usually very reliable for spark quality. Maybe he is losing voltage when hot affecting the DUI and the Starter? Keep us posted you have an odd situation. I used an HEI on my 87 Malibu for 20 years trouble free, good cold starts and always performed well with zero maintenance. Maybe we could use the Terms: Closed System and Open System to describe the cooling options for clarity. ------------- |
Posted By: KENO
Date Posted: December-30-2019 at 9:58am
Then what would you call the raw water pump? |
Posted By: Wilhelm Hertzog
Date Posted: November-18-2020 at 8:59am
To follow up, after doing the following, the hard starting issue is hugely improved:
By and large, the engine starts easily now. On occasion the engine still struggles to start when hot though (turns over easily, but takes a few seconds to start up). I did notice fuel dripping from one of the primary boosters after shutting off the engine on one occasion, which I suspect may be the cause of the remaining occasional hard starting. I'll clean out the needle and seat assembly and perhaps lower the float level a touch to see if that resolves the dripping. By the way, I have read here on the forum that because of the angle at which direct drive engines are mounted, carb float levels as recommended by Holley may not be optimal. How should the primary and secondary floats be adjusted (raised/lowered) for optimal performance in a direct drive marine application?
------------- 1982 Ski Nautique PCM351W RR II Velvet Drive 10-17-003 1:1 II PerfectPass Stargazer Do not go gentle into that good night. Rage, rage against the dying of the light. |
Posted By: MrMcD
Date Posted: November-18-2020 at 5:41pm
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You would need to slightly lower the floats to avoid flooding due to the angle. Glad your making progress. Mark ------------- |
Posted By: Wilhelm Hertzog
Date Posted: November-19-2020 at 1:56am
Will the angle not mean that the fuel level is higher against the front/primary metering block and lower against the rear/secondary metering block, so a slightly lower front float level and slightly higher rear float level than normal will be required? ------------- 1982 Ski Nautique PCM351W RR II Velvet Drive 10-17-003 1:1 II PerfectPass Stargazer Do not go gentle into that good night. Rage, rage against the dying of the light. |
Posted By: KENO
Date Posted: November-19-2020 at 7:07am
What you're thinking sounds good, but most people will adjust the front float slightly lower and leave the rear float alone and have no problems. If you really want to adjust the rear, raising the level a slight amount like you said would be the right way to go
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Posted By: GottaSki
Date Posted: November-19-2020 at 7:51am
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Consider changing the battery sooner than later, i predict you will be startled how fast it turns over with the right juice. Our regrets not inquiring about your battery immediately, there was a rash of starting inquiries last year and we probably began sounding like parrots; squawk, no deep cycle, squawk, no fish motor batteries ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |