1994 PLP multi coil pack testing protocol
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=47190
Printed Date: September-16-2024 at 3:59pm
Topic: 1994 PLP multi coil pack testing protocol
Posted By: Kiwi Dave
Subject: 1994 PLP multi coil pack testing protocol
Date Posted: February-11-2019 at 10:11pm
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Hi I've got a 1994 Ski Nautique with a PLP 5.8 lt Ford motor. This has been getting more a more difficult to start from cold (but runs and starts sweet when warm). I suspect there was a sticky needle valve in carb as it would always eventually stutter to life. Now it wouldn't even splutter. Plenty of power in battery so I've taken the plugs out and discovered a very weak spark so suspect also a fault in the multi coil pack, hall effect sensor (or something associated with this). Can anyone advise a protocol for testing with a multi meter to help eliminate or confirm my suspicions. Cheers |
Replies:
Posted By: Jonny Quest
Date Posted: February-11-2019 at 11:13pm
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Welcome Kiwi Dave. A 1994 "PLP" engine with the 4-pack coils has the Pro-Tec engine management system that PCM developed in the early 1990's. Many PCM engines of that vintage had the Pro-Tec installed. I'm part of the Pro-Tec club as I also have a 1994 Ski Nautique with a "PLP" engine that came from the factory with the Pro-Tec system. The symptoms that you are describing are consistent with a Pro-Tec that is dying. My experience was similar. Start, then no-start. Then for no apparent reason, start again. Eventually, the Pro-Tec on my PLP engine finally died in the middle of a very large lake. I had to be towed back to the marina. No joy there. Now for the fun part...repair parts for the Pro-Tec system are no longer available. I called PCM and spoke with one of their senior technicians who was very familiar with the Pro-Tec EMS. He recommended that I completely remove the Pro-Tec system and retro-fit the engine back to a distributor based ignition. So, that is exactly what I did. As it turns out, several members on this forum have done the exact same retro-fit. The link below will take you to the discussion containing pictures an a tidy write-up of the procedure. http://www.correctcraftfan.com/forum/forum_posts.asp?TID=34338&title=protec-ignition-swap" rel="nofollow - LINK to Pro-Tec Swap-Out Thread Good luck. JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: Smithfamily
Date Posted: February-12-2019 at 8:58am
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Hello and welcome Dave! I suffered the same with my 92 Pro tec. I bought the boat with a bad head gasket, rebuilt the entire engine, put it all back together and it ran great until the Coil pack started to break down. No parts available, and used was a consideration until I started to hear all the similar stories. I would just be waiting for another breakdown! Retro fitted to the old style distributor set up and no worries (8 years now) However make sure you get the high heat coil. Good Luck! We like to see pictures! ------------- Js |
Posted By: rosconole
Date Posted: February-12-2019 at 10:39am
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They quit making PCM kit , I think your 2 options are DUI distributor or MSD marine kit pretty much at this point . It a much happier engine with the old style setup. starting is much improved no random backfires. Make sure you close down the gap when you put new plugs in upon install. its a smaller gap on regular distributor. Just use an earlier year for reference.. Only difference in system is you have low pressure electric carb fuel pump. ------------- 1989 ski nautique ,1991 barefoot nautique, 1993 Mustang Cobra 1998 5.0 Magazine shootout invitee |
Posted By: phatsat67
Date Posted: February-12-2019 at 12:06pm
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MSD and DUI are likely the same or larger plug gap compared to the factory Pro-Tec ignition. Plug gap is set based on the power output of the coil used in the ignition system. DUI is the cleanest easiest setup and likely most reliable. |
Posted By: Orlando76
Date Posted: February-12-2019 at 12:10pm
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I believe DUI wants a .055 gap. ------------- Please support The Cystic Fibrosis Foundation 1976 Ski Nautique 351 Escort 1993 Ski Nautique purple and black 351 HO PCM |
Posted By: phatsat67
Date Posted: February-12-2019 at 12:13pm
| From memory I believe that is what they recommend. Install instructions will tell you when you get it. Stock Pro-Tec is .045 |
Posted By: JPASS
Date Posted: February-12-2019 at 12:36pm
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DUI gap recommendation is 0.050 - 0.055 ------------- '92 Correctcraft Ski Nautique |
Posted By: 8122pbrainard
Date Posted: February-12-2019 at 1:08pm
Ross, Before someone makes a mistake after reading this, could you confirm the plug gap? It sounds like others have a different idea. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
rosconole wrote:Posted By: KENO
Date Posted: February-12-2019 at 2:05pm
Roscoe You once again have a gap in your info A ProTec 454 had an electric fuel pump to supply the carburetor, a ProTec 351 with a carburetor has a mechanical fuel pump Another distributor choice is a complete Pertronix marine distributor for a 351w (only for normal rotation like Kiwi Dave's PLP engine. |
Posted By: KENO
Date Posted: February-12-2019 at 2:07pm
It's the Amsoil gap Pete 
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Posted By: rosconole
Date Posted: February-12-2019 at 4:06pm
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I have seen some that had an electric low pressure pump so , maybe in the change over year to year. .035 on the plug gap NGK usually comes out of the box around .036. , .050 is a little much for good idle quality from ones I have seen run. Maybe the DUI runs hotter and that is alot for any naturally aspirated engine, but I would bet if you close it down you would be suprised. I didn't recommend Pertronix because they have been not as reliable for me and a few other people. Its a decent product , Just support and reliability is not as good. I talked to them personally at trade show and they were not focused on marine market. ------------- 1989 ski nautique ,1991 barefoot nautique, 1993 Mustang Cobra 1998 5.0 Magazine shootout invitee |
Posted By: 8122pbrainard
Date Posted: February-12-2019 at 6:50pm
Ross, Sounds like you still are off on the gap especially with the "maybe" in your comment. So, I did a quick search on what is recommended. Here's what I found on the DUI: "Improved performance comes from our 50,000 volt coil and high dwell Dyna-Module. The coil allows spark plug gaps to be opened up to .055″. The increased dwell within the module makes the coil produce a longer duration spark. The combination of the two will provide the most complete burn of the fuel mixture possible." We sure don't want anyone gapping their plugs wrong after installing a DUI and getting surprised! ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: phatsat67
Date Posted: February-12-2019 at 6:55pm
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Ross presents good info to show folks what not to do. So there's that? Would be safe to say read the recommendation then do the opposite and you're golden, |
Posted By: rosconole
Date Posted: February-12-2019 at 7:11pm
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its ok I can make instructional youtube videos for all you guys think I am full of it and everything on the internet is real life. ------------- 1989 ski nautique ,1991 barefoot nautique, 1993 Mustang Cobra 1998 5.0 Magazine shootout invitee |
Posted By: KENO
Date Posted: February-12-2019 at 8:05pm
Rosco You've seen an electric fuel pump on a carbureted ProTec 351W, but......I've seen Elvis a few times myself.. I have to admit, I went out and looked at my old truck that has plugs gapped at .060 factory spec. I was looking for a supercharger or maybe a turbo that I never knew was there It wasn't there, what gives? By the way, I'll give you extra points for entertainment value, not many but a few. You do keep me laughing after all. |
Posted By: rosconole
Date Posted: February-13-2019 at 1:56am
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You should open your own Marine mechainic shop since you are all know on everything. You old truck with rust holes in the floor boards? Or was it a F150 that shoots spark plugs through the hood. Atleast I know why they have lifetime warranty on spark plugs now. Ordered your commemorative Elvis plates for Christmas. ------------- 1989 ski nautique ,1991 barefoot nautique, 1993 Mustang Cobra 1998 5.0 Magazine shootout invitee |
Posted By: 8122pbrainard
Date Posted: February-13-2019 at 6:06am
 ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: KENO
Date Posted: February-13-2019 at 9:41am
We'll give you one more point for entertainment value,
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Posted By: desertskier
Date Posted: February-13-2019 at 12:19pm
The coil kept the plug in the hole so no hood damage. Don't ask me how I know that! Also, I may have a couple of working protec units available this summer. I just ordered the parts for a DUI conversion. Boat still runs fine but I retired a few weeks ago and needed a project. I would prefer to give the parts to someone with an EFI boat since the carbed boat conversion is pretty cheap and easy. I will post them when I finish the swap. |
Posted By: Kiwi Dave
Date Posted: March-18-2019 at 12:43am
   Just to close the loop here with before and after photo's. Boat all fixed with power pack replaced with distributor and coil. I also managed to screw out the reductive starter motor prior to this all unfolding (a stupid design with tiny little plastic cogs used to drive the starter mechanism,) so replaced with an old school direct drive starter - bolted straight in. Installed two relays (one for power to new coil as was having voltage drop, and one for solenoid for starter as now drawing heaps more amps with the direct drive starter). Motor starts sweet as now, but yet to try it in anger on the river - hopefully this coming weekend. Thanks everyone for your comments and support Kiwi Dave |
Posted By: desertskier
Date Posted: March-18-2019 at 12:14pm
| I think the relay for the ignition is a good idea. When I do the swap I plan on adding two relays for the ignition voltage. One N.O. in series with one that is N.C . The N.O. relay will be closed by the key switch voltage probably similar to what you did. The N.C. will be connected to the existing over temp and low oil pressure switches. If one of them detects a fault then the engine will shut down. The switches are open until they detect a fault then they connect to ground so the connection would be to the low side of the relay control. |