1996 Gt-40 Heat Soak
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=27017
Printed Date: May-15-2024 at 6:30am
Topic: 1996 Gt-40 Heat Soak
Posted By: Captain Ken
Subject: 1996 Gt-40 Heat Soak
Date Posted: July-17-2012 at 11:18am
| Twice in the last week I have skied for two hours and then turned the engine off for an hour while we swam. The engine would restart, run slightly rough for about 30 seconds and die. It would not restart. The red light indicating overheating came on for a minute or so, but then went off. The temperature gauge indicated only slightly elevated operating temperatures below 200. I suspect some sort of heat soak problem. When the engine cooled down completely, it ran fine again. |
Replies:
Posted By: Captain Ken
Date Posted: July-17-2012 at 1:06pm
| I checked the impeller in the water pump, the thermostat, and the water strainer. They are all fine. |
Posted By: Bri892001
Date Posted: July-17-2012 at 1:39pm
|
Is the engine actually overheating? It sounds like it's not, right? I'm thinking this could be a fuel pump relay problem. Are your fuel pumps priming when you turn the key... after it's hot? Look through this thread, and at the linked spreadsheet, and see if anything clicks: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25584&PN=1&title=poor-mans-gt40-diagnosis" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25584&PN=1&title=poor-mans-gt40-diagnosis |
Posted By: Captain Ken
Date Posted: July-17-2012 at 2:09pm
| When I turn the key half way, I can hear the low pressure pump come on. Could it be vapor lock? Both days it was 96 degrees out. |
Posted By: TRBenj
Date Posted: July-17-2012 at 2:15pm
|
I believe Jody has confirmed that some of the early GT40's were in fact susceptible to heat soak. Does your boat have a FCC? ------------- |
Posted By: Captain Ken
Date Posted: July-17-2012 at 2:16pm
| Yes it does. |
Posted By: Bri892001
Date Posted: July-17-2012 at 2:17pm
|
Would you normally hear the high pressure come on as well? Does this have a Fuel Control Cell? That is supposed to help with vapor lock among other things. Others could comment more on vapor lock, it's usually dismissed, but at least one experienced guy has said it's possible. Look at Jody's (Fl Inboards) post in this thread: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=21949&title=vapor-lock-fix" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=21949&title=vapor-lock-fix |
Posted By: Captain Ken
Date Posted: July-17-2012 at 5:09pm
| I telephoned PCM and they say it should not vapor lock if the fuel system is operating properly. They say check for a weak or bad low pressure fuel pump, a restricted fuel filter, or a corroded fuse in the Keep Alive Wire near the battery. |
Posted By: lewy2001
Date Posted: July-17-2012 at 9:47pm
Ken check this thread out about the http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25723&KW=&title=gt40-retrofit-computer-power" rel="nofollow - "Keep Alive Wire" "you can make both pumps run by shorting the end terminal of the STO connector to ground (ECC Test connector above relays). You should have 39 +- 3psi with key on engine off and 31 +- 3psi at idle. With the vacuum hose removed at regulator and engine running you should see max pressure mine reads almost 44psi. I would also check the volume of fuel the low pressure pump puts out." From the http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25775&KW=&title=99-sn-gt40-fuel-supply" rel="nofollow - GT40 Fuel Supply Have a look at that thread it goes into some more detail. ------------- If you're going through hell, keep going http://www.correctcraftfan.com/diaries/details.asp?ID=2999" rel="nofollow - 89 Ski <a href="http://www.correctcraftfan.com/diaries/details.asp?ID=5685" ta |
Captain Ken wrote:Posted By: levinmark
Date Posted: July-17-2012 at 10:05pm
|
I'm going to chime in since the vapor lock theory was stated. I swear I get in my 96' if I do not lift the doghouse after sets, however it is carb'd. Ill try to make this short. In Arkansas it was hot as heck the first day we were there, made some runs as did the wife, shut it down (did not open the doghouse), sat for about 20-30 min. Went for a run and about 8 seconds in, boat started to bog down but did not die ran fine after a couple minutes. I always lift the doghouse in between sets to help with cooling, but did not this time. After the bog down I lifted the doghouse everytime we shut it down for an extended period of time and never had another issue for the rest of the week, and it got hotter (105,107,etc.) Since then I have had no issued what so ever. Last week, I went for a couple runs and after one of them we shut it down for about 20-30 minutes and I did not lift the dog house. I had a suspicion that the bog might return, as wouldnt you know it, right as I get pulled out of the water gaining speed, she starts to bog down again. Opened the doghouse anytime we stopped after that and never had any issues. Call me crazy, but I believe in the vapor lock theory. Mark ------------- levin |
Posted By: Bri892001
Date Posted: July-18-2012 at 12:55am
| Mark, does running your blower during shut downs help the same as lifting the doghouse? |
Posted By: levinmark
Date Posted: July-18-2012 at 9:13am
|
When I shut down changing skiers I turn the blower on, but usually lift the doghouse when we are going to be sitting for a while. I have never tried the blower for an extended period of time. Kind of puts my mind at ease to really "air" it out after runs. It makes it hot as heck in the boat, but we jump in anyway so no one is really unconfortable from it. ------------- levin |
Posted By: Bri892001
Date Posted: July-18-2012 at 1:12pm
| Mark, sounds like any kind of restrictions (such as a dirty fuel filter or anti-siphon valve or degrading fuel line) on the SUCTION side of your fuel pump, could create conditions for vapor lock. |
Posted By: Captain Ken
Date Posted: July-18-2012 at 4:05pm
|
Update on GT-40 Heat Soak and possible Vapor Lock: I took my boat to the dealer. The low pressure fuel pump tested okay. The fuel filter inside the FCC was very dirty. The line into the FCC was loose. The fuse on the "Keep Alive Wire" was not corroded, but since 1999 PCM recommends re-routing it to the 60 amp breaker at the back of the engine. ------------- 1996 CC SN GT-40 |
Posted By: Bri892001
Date Posted: July-18-2012 at 4:13pm
| Definitely let us know if the fixes help. |
Posted By: levinmark
Date Posted: July-19-2012 at 11:38pm
|
Brian, I think your on to something regarding the fuel line. I am almost certain that the fuel line is the original one, so degrading definetly could be an issue. I have cleaned the anti-siphon valve a couple times and have replaced the fuel filter. I guess I will add a new fuel line to the project list. Thanks for the input ------------- levin |
Posted By: mdvalant
Date Posted: August-07-2012 at 2:59pm
|
Hey Ken, do you remember the Valant's from Bellevue with our 1990 red and black Nautique? Just noticed your boat in the for sale here in Dubuque!!! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=5009 - '90 Ski (sold) http://www.correctcraftfan.com/diaries/details.asp?ID=5479 - '00 Sport Mississippi River - Bellevue, IA |
Posted By: mdvalant
Date Posted: August-07-2012 at 3:00pm
Sorry, not "for sale" but in the diaries!  ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=5009 - '90 Ski (sold) http://www.correctcraftfan.com/diaries/details.asp?ID=5479 - '00 Sport Mississippi River - Bellevue, IA |