GT-40 Suddenly Died
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=51097
Printed Date: November-22-2024 at 9:38am
Topic: GT-40 Suddenly Died
Posted By: MI-nick
Subject: GT-40 Suddenly Died
Date Posted: April-14-2023 at 8:27pm
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Beautiful day...about ready to strap my board on...boat was idling fine then died suddenly. No stumble, no sputter...went from a smooth idle to dead and would not restart. A couple times seemed like it would almost catch, but nothing. I pulled a plug and verified I had spark. Tried to connect my code reader, but it would not initiate a test, so I don't really know what that means. Starting this thread while I dig into past threads and the service manual. Any advice is appreciated as always. '99 SAN with GT-40. ~1200 hours. Put the boat on the lift last friday. It fired up fine and ran fine last friday, saturday, sunday. Fired up fine today. Warmed up for about 5 minutes, idled to my start spot for maybe 10 minutes. Dead. Wont restart. Cranks fine. I'll also add that I can hear the LP pump run when I first turn the key. FCC filter was replaced last fall. ------------- As far as I can tell, I'm not quite sure... |
Replies:
Posted By: bwinn
Date Posted: April-14-2023 at 8:55pm
| I’d start with a fuel pressure reading at the rail. |
Posted By: JamoJones
Date Posted: April-15-2023 at 12:03pm
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Kind of off your topic, but could you tell me how I find out if I have GT 40 heads or not? I bought an '87 SN project that came with a rebuilt 351W from Marshall's Marine. I have no idea what heads. Still a Ford block. Thanks... Jamo ------------- 1986 Silver Nautique #49 of 82 1987 Ski Nautique 2001 |
Posted By: KENO
Date Posted: April-15-2023 at 1:35pm
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Look at your heads for markings like the picture below. 3 bars would be gt40, (there were also some early gt40 heads with 2 bars) 4 bars would be gt40P no bars, just smooth in that spot, would be standard cylinder heads The markings are on the front and back of each head https://ibb.co/k1xhDGJ" rel="nofollow">
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Posted By: JamoJones
Date Posted: April-15-2023 at 4:49pm
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Thanks Keno...just checked, mine are standard heads... ------------- 1986 Silver Nautique #49 of 82 1987 Ski Nautique 2001 |
Posted By: KENO
Date Posted: April-15-2023 at 7:03pm
| Back to our regularly scheduled programming, how's that fuel pressure Nick? |
Posted By: MI-nick
Date Posted: April-15-2023 at 9:32pm
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Spent a couple hours testing things today and I think it's the HP fuel pump. Here is what I checked. - New EEC-IV tester. could not get the ECM to enter test mode. same as with old tester. - Replaced both ECM/Fuel pump relays and re-tried the test. Still nothing. Jumped the STI to ground, still nothing. - Checked fuel pressure with key on, ignition on. 0 PSI - Depressed valve on fuel rail and barely a few drops came out. - Jumped STO to ground to run fuel pumps. HP pump not running. - Confirmed 12V at LP pump and 12V at HP pump with STO jumped to ground. - Confirmed FCC full of fuel. Seems pretty cut and dry to me that the HP pump is my problem. I'm a bit bothered that I couldn't get the ECM to enter test mode, but I don't really know what that means. Thoughts?
------------- As far as I can tell, I'm not quite sure... |
Posted By: winniskier
Date Posted: April-15-2023 at 9:50pm
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Check the kill switch. ------------- Jim |
Posted By: KENO
Date Posted: April-16-2023 at 8:00am
Seems pretty cut and dry to me too, since it has 12 volts supplied and it's not running  Maybe there's a slim chance it's running and the little connector hose inside the FCC just plain fell apart............maybe however slim I guess the FCC will be coming apart soon
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MI-nick wrote:Posted By: MI-nick
Date Posted: April-16-2023 at 8:22am
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yep, that's my next step. I'm going to go ahead and order an new HP pump though. If it's simply the connection inside the FCC, then i'll have a spare. spare parts help me sleep good at night. ------------- As far as I can tell, I'm not quite sure... |
Posted By: MI-nick
Date Posted: April-16-2023 at 8:40am
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any thoughts on why I can't get the code reader to run the KOEO test? ------------- As far as I can tell, I'm not quite sure... |
Posted By: bwinn
Date Posted: April-16-2023 at 9:08am
Walbro has a hp pump available at a fraction of the cost just need to order a plug with it. |
Posted By: bwinn
Date Posted: April-16-2023 at 9:19am
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Walbro GSS340 $57 on Amazon currently HiSport wiring plug harness connector 94-615 $6 Fuel filter RP080026 $33 Hope this helps |
Posted By: MI-nick
Date Posted: April-16-2023 at 9:31am
well, it would have been if I hadn't already ordered  . oh well, i'm sure this will be helpful for others that need a new pump------------- As far as I can tell, I'm not quite sure... |
Posted By: MI-nick
Date Posted: April-16-2023 at 5:33pm
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well, I took the FCC bowl off this morning to find the power lead the HP pump disconnected. the spade connector was very loose so I squoze it a bit re-attached. 38 psi with key on. fired right up. Went for a quick ride before the wind and rain. cancelled my pump order. wish I would have checked fuel pressure friday night...i got hung up on the code reader not working and starting thinking worst case... ------------- As far as I can tell, I'm not quite sure... |
Posted By: KENO
Date Posted: April-16-2023 at 8:11pm
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You get one of these 
Now from one spare parts guy to another, you need to get the cheaper HP pump for a spare and a cheap LP pump to go with it, just to insure that you won't need them for a long time........but when/if you do they're right at your fingertips.
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Posted By: NCH20SKIER
Date Posted: April-17-2023 at 7:18am
To Keno's point above when my '96 sport suddenly died the small black hose inside the FCC failed (~3/8 split) in it. Replaced that and it was good to go ------------- '05 206 Limited '88 BFN |
Posted By: MI-nick
Date Posted: April-17-2023 at 7:59am
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i definitely have the FCC hose in the spare parts cupboard. going to look into that cheap HP pump for a spare. I have my old LP pump as a spare. it was still working when I replaced it, just not functioning due to being clogged up with junk. the BIG question is do I want to give Nautique Parts the $900 they want for a spare ECM? ------------- As far as I can tell, I'm not quite sure... |
Posted By: Gary S
Date Posted: April-17-2023 at 9:36am
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It's all been gone over here before. Perhaps if you'd do a search.... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: MI-nick
Date Posted: April-17-2023 at 12:05pm
the ECM question, you mean? I've gone over many of those threads previously. i think the ECM options are basically try to find a donor in working order, buy a similar Ford ECM and re-program or have it re-programmed, or buy one that's already been re-programmed (Nautiqe parts, GT40 Marine, Miami Ski Nautiques...maybe others?)? are there other options? ------------- As far as I can tell, I'm not quite sure... |
Posted By: KENO
Date Posted: April-17-2023 at 6:43pm
Perhaps a search won't do a whole helluva lot of good right about now, since the Moates people closed the doors and retired in Nov of 22 and trying to get parts like the f3v2 chip (that the tune gets burned to and then gets put into the donor ECM) is probably kinda tough. A price check in aisle 1 says that the price at NP is 1150, but you can get a 10% discount and gt40 marine is 999 and ol' gt40 Mikey is looking for someone to solve his lack of chip issue.
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