I get in the water for about 10 minutes. warm up, full speed only 1 time for about 20 seconds. Temp = good. oil pressure = good. everything looks like it is going to be a normal day. I go back to dock, pick everyone up and cruze out of no wake.
hit the throttle and... 1800-2000 rpm's it starts to cut out. it feels like it is starving for fuel. temp = good. oil = good.
we swim around for the day... boat never runs right agian that day. i did idle around the swin area. only idled around for maybe 30 minutes.
(to the shop) fuel pressure test = Fail Replaced both the high flow and low pressure fuel pump due to low pressure. still having problems. they pull and rebuild the "Fuel Reservoir vapor Separator" Float and pin were old and flakey/dirty.
1500.00 bucks later, (800 in parts) I get the boat back and the Mech says "Green light running good". all smiles at me.
i repeat the same thing above... in the water. full speed, 3-4 times and for about 10-15 minutes for testing. no problems at all, and it really did feel like a fresh tune up.
back to dock, grab everyone, idle out, 1st tube in the water. maybe 30 seconds into the 1st tube ride, and same issue. about 1800-2000 rpm's is all it will do until it starts to cut out.
My idea is . . . that it is an RPM limiter issue. It has become heat sensitive and once the engine warms up it is limited for the day. It is supposed to protect the engine when shifting, but sometimes it gets screwed up or becomes faulty.
This happened to a friend of mine and it was a bugger for the shop to diagnose. (i.e. they couldn't fix it) He took me for a ride and I told him it was doing the RPM limiting thing. The shop then replaced some sort of 'module', problem solved.
Edited by tpenfield (06/14/0804:14 AM)
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tpenfield 1991 Formula 242SS
I had a similar problem that turned out to be loose exhaust flappers. They came loose from their mounts and were wedged farther downstream in the exhaust, blocking exhaust flow. It started out as an intermittent problem then became a full time problem. It would run fine up to about 2,000 rpms, then really struggle to gain rpms after that. I could nurse it up to about 3300 rpms or so, but it was hard to get the boat up on plane and the boat had a funny high pitched exhaust note at higher rpms.
It sure felt like a fuel problem to me as well, but my fuel pressure checked out. Three mechanics looked at it before they figured out what the cause was.
"loose exhaust flappers" could be... i dont think so, because when the boat is cold... i can get up to full speed. (until the boat seems to get 160) also, I just got a new gimbal berring at the beginning of this year. and when they were doing that they DID find the Exaust flap, all weaged in there in the wrong spot. the Pin that holds it in place had fallen out. So new pin and new flap and big $$$ Labor.
"RPM limiter issue" is 'heat sensitive and once the engine warms up' this i would agree with. because the engine feels starved for fuel or like it is missing real bad. when you say, "The shop then replaced some sort of 'module', problem solved." i wonder if they meant the Eletronic Control Assembly(ECA)? That is the Brain of the EFI from what I understand. $900 part
I had another person say it could be the "Throttle Position Sensor." This may have water in it, so when it warms up it shorts out, causeing the motor to go all goofy. Any thoughts on that?
Registered: 07/10/06
Posts: 1412
Loc: Eastern Washington
I would check the ECA. The RPM limiter will allow you to get to 1800 RPM or so and then drop out cylinders until the RPM falls below that point. The more gas you give it, the worse it will run in order to keep the RPMs down.
It's a safety device designed to let you limp home in case of an overheat or other engine problem.
Sorry you had to spend $$$ on parts that did not fix your problem, however it sounds like you needed the fuel pumps anyway. Low fuel pressure can make it run lean and then it goes BOOM.
I would check the ECA. The RPM limiter will allow you to get to 1800 RPM or so and then drop out cylinders until the RPM falls below that point. The more gas you give it, the worse it will run in order to keep the RPMs down.
i have a battery Switch. A B Both and off.
when i got done, I did as normal, turned this off. will the ECA keep the Error code? or will it drop out due to no power at all. I'm sure i could just hit the lake again, and make this happen again.
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