View Full Version : Engine Trouble

07-21-2006, 02:44 PM
Ok Gang Working on the 'rents Maristar 210 with the 5.7 TBI engine.


Was ran out of gas once and runs alot with less than 1/4 of a tank.
About 3 weeks ago it was running and the alarm went off, cut it back to idle and limped it back home. I was not there and they thought it was the impeller, needed replacing anyway so they did that. Took it out and it happened again. Bought a new fuel pump and my brother installed it today. It cranks and idles fine, it will run WOT but if you back off of the throttle the alarm comes back on and it is unhappy. If you shut down the engine, and restart it will crank right back up and run fine until you decrease the throttle and the same thing happens. I am on my way over there in the morning and am taking a bottle of seafoam as there might be some bad gas in it. They are going to run the gas out of it and put some fresh in. Like I said, it will run WOT just gets upset when you drop the throttle. They are going to put some fresh gas in it tonight and I will sea foam it up just as a cleaning procedure tomorrow.

Anybody got any thoughts on this? Really don't want to have to take it to a dealer this time of year.

07-21-2006, 02:56 PM
put a fuel pressure gauge on it, think about the map or TPS, I doubt bad gas because WOT is ok.

check engine light on ?


07-21-2006, 03:14 PM
Don't know for sure about the check engine light, but I think it comes on after the alarm.

Are MAP and TPS sensors hard to get and are the expensive?

07-21-2006, 03:21 PM
pulling ecm codes might make your life easier, map and tps are not expensive but I don't recommend throwing parts at it, get some help with diagnostics or tow it to reputable shop.


07-21-2006, 03:24 PM
Well we are going to the throwing parts at it route for the time being. There are going to be about 50 upset people if it is not running tomorrow. They are at NAPA now buying new plugs, new pcv valve, Throttle Position Sensor and MAP sensor. Throwing parts at it is fun when it's not my dime. :D

07-21-2006, 04:36 PM
if parts changer it is, do them one at a time, do a battery reset on every repair, [disconnect the battery].

anyone in your group own a volt meter and know how to use it ?

of-course start by making sure your battery connections are clean and tight.


07-21-2006, 04:42 PM
Several Volt meters, (We do some work as part time electricians).

Sadly, or not to say I think we/they have found the problem.

Apparently one of the screws in the impeller housing cover was missing and water would shoot out under pressure causing the engine to overheat.

Now we/I am trying to find a replacement screw.

And no this isn't like JRandol where They is me.

Somebody got a receipt?

Thanks for the help!

07-21-2006, 09:31 PM
sorry to hear about your overheating, if it overheated enough to run poorly that cannot be good. keep us apprised, I hope for the best.


07-24-2006, 10:40 AM

Learned several things this weekend.

1) Don't try and troubleshoot mystery boat issues over the phone with family members that don't work on them.

2) Don't let anybody else work on boats that you are maintaining

3) Teach the other drivers of the boat how to look at the temp gauge

They tell me that it just quit running right and wouldn't go over idle, knowing it has been run out of gas, thought fuel pump, but said hey why don't we replace the impeller first to see if that is it. Sent a moron to change it, he broke the head off one of the screws that holds the cover on, didn't tell anybody. Took it out for a test drive, ran fine (until it got hot and the limp back home mode kicked in), on the test drive we apparently didn't look at the temp gauge. So we replace the fuel pump, took it out for test drive, this time we notice that it is in fact running better than before, but then it over heated, so it is observed that a screw is missing on the water pump. They go all over town looking for a screw, I call a MC dealer and see if they have one, no dice, finally find something that will work. (wouldn't you want to keep screws like that around if you were a dealer?) Try to put one in and see that the old screw is broken off in the pump. It is now determined that the impeller and the housing was the issue all along. I go and get a water pump from an inboard boat dealer and head to the lake. Install the water pump and take her out for a test drive, overheats again. I am now for the first time troubleshooting this boat first hand, pull the t-stat cover and pull out the thermostat, replace the cover and crank the boat, (also noticed that there hadn't been any water in the hoses above the t-stat) and she ran like a champ, a bit cool, but ran good. So all of that for a thermostat. Possibly the easiest fix on a V-Drive boat.