1994 Pro Boss, Stalls After Starting

Help! I have a 1994 5.8L Pro Boss with the Pro-Tech Injection system (throttle body injection). The boat will start and then die after a minute or two. I just put the boat into the water after taking it out of winter storage. My summarizing routine is to change the oil, oil filter, gas filter and spark plugs (gaps checked).

My first thought was that the gas went bad so I added 6 gallons of premium gas (to bring the tank to full) and added a bottle of HEET and a half bottle of Sea Foam. I removed the gas filter and emptied it to see if I had water and I did not have water in the filter.

Normally, with my engine, when I turn the key to on, the gas pump cycles and it normally squirts gas into the carburetor, it does not seem to do that anymore. The only way I can get it to do that now is to turn the key quickly to start and all four injectors begin to squirt gas into the carb. It takes me a couple of times doing this to get the engine to start.

Once the engine starts, it idles fine, everything sounds good, purrs like a kitten for like I said about a minute or two and then it just dies. The injectors fire gas continuously. (One note, the carb flaps never open unless I rev it.)

I’ve done a visual check and everything looks good, all of the connectors are tight, spark plug wires are snug on both ends, metal air filter is clean.

Anyone have any ideas for me to try?

THANKS!!!

Assuming the engine is okay mechanically, you need to figure out if the problem is lack of spark or a fuel issue...a clip on timing light is the quickest way to verify the spark is good and constant... a fuel pressure test would also be beneficial but I can't remember is that system has a schrader valve for hooking up the guage...

They have ignition problems, the ignition box likes to ground out, look for arching plug wires

Thanks guys. Here's where I'm at. I checked the plugs. They all spark. No arc-ing. The alternator is putting out 18 volts. I also disconnected every connection I could find to make sure there wasn't any corrosion or I had a loose connection. The battery is good. I put a fuel pressure gauge on it (and yes there is a shrader valve on it, right off of the carburetor) and it's putting out 16 pounds at idle and when I rev it. It loads up at 16 when I turn it on, and it holds at 16 pounds for several minutes after I turn it off.

It's hard to start, I have to try 5 or 6 times before it'll kick over. And as I mentioned above, it'll run for about 2 minutes and just shut down regardless of whether it's at idle or rev-ed.

I'm open to suggestions! Thanks again for the help!!!

Did you check for spark still being there when the engine stops running?

Hi!
Well, here's where I'm at. I pulled the boat and took to my mechanic - it's out of my realm now. And now we’re totally perplexed. So, whatever help you can throw at us would be greatly appreciated.

Makomark, you were correct, no spark. He put his spark tester on it and it starts (hard) and runs for about a minute and then the spark quits.

His diagnostic meter indicated the ignition coil packs (R117006) were bad, and I think we found the last two in existence! We changed them out and the meter says everything is working, but it does the same thing; starts hard and then dies, no spark.

We tried calling PCM, but sadly, they were no help.

We checked all of the connections, cleaned them and checked for corrosion, they all look good.

Any ideas or suggestions?

THANKS!!!

There's an outfit in SC (i think) that has a retrofit kit to eliminate the PT ignition system...skidim.com...you may want to do a www search and give them a call.

Hi Makomark,

I really don't want to go that way. I already know about converting to a carburetor:

Carb kit# RF052019/03 and Distributor kit# RK107025A

The problem is the two kits run about $1800 plus labor ($1200 for the Skidim kits).

I’d rather fix the problem if possible. Any other ideas?

I think the big issue, as you have seen, is going to be lack of parts... :-(

You might want to check some of the ski boat forums but I think you'll find the consensus is to convert to something more basic...you may be able to piece out what you know is good (e b a y) and recoup most of the conversion costs...

A more economical way might be to DIY vs buying the kits...not rocket science but a lot less convenient.

Yeah, lack of parts is frustrating (and the cost!)

We think we have the problem narrowed down to two parts, but we can't figure out how to determine which one it is (and they're both $600 and I "think" I've located each of them). Replacing one is a whole lot cheaper then converting over to the old distributed system.

We're getting power in and out of both parts and that's as far as we can test. We haven't been able to determine how to test the two parts so we don't know which, if either is bad. We think it's either the main computer (R116006) or the ignition module (RA107031), and we can't find a diagnostics routine. Anyone have a diagnostics manual floating around?

Any ideas how to narrow it down?