PDA

View Full Version : starting problem after heavily worked


canada air
07-05-2005, 06:59 PM
i have 95 maristar v-drive. we usually wakeboard with 1500-2000lbs. after wakeboarding for 20minutes. we shut off boat. 5 min later go to start boat and i have to move throttle lever forward for it to start. it has 275hp tbi 350. clean flamearrestor,new plugs, ecm updated, injectors and tbi cleaned, compression 155 across the board, new fuel filter. the only thing have not checked is timming. boat runs about 4300rpm wot. otherwise this boat runs awesome.

chico
07-05-2005, 07:32 PM
don`t forget to check your battery. you need 11.5 volts while cranking for the electronics to work right.

Thrall
07-05-2005, 07:35 PM
I don't know exactly how to diagnose it, but if you have to open up the throttle to get it to start, your TPS (throttle position sensor) is likely malfunctioning.

Davo
07-06-2005, 11:23 AM
I've had to do that with my '02 w/350 TBI since it was new. I had the dealer change out the ECM early on which seemed to help somewhat, but I learned to just deal with it.

HOWEVER, I have found that it happens more often when the temp creeps up after shutting it off. If I leave the hood open and/or let it cool after running it seems to start easier. I don't know what that could possibly mean though.

I've got 440 hours now and it runs perfect otherwise.

NeilM
07-07-2005, 01:27 AM
Hmmm... sorta reminds me of the lady who told the dealer that her car won't start after she gets a soft Vanilla Ice Cream Cone, but works fine with other flavours...

After many visits to the shop, a factory engineer finally accompanies her to the ice cream store. She goes in, buys a vanilla cone, comes out, and presto, her car won't start.

They get it going, then repeat the process, only she gets a different flavour -- the car starts just fine.

It took a long time before they figured out that the difference was time. The soft ice cream machine was in the front of the store, and lineups were short. A vapour lock would develop.

The flavoured hard ice cream, though, took longer to get (through the queue, as Sizzler would say), and longer to serve, so when she got back to the car, the lock was already cleared.

jimmer2880
07-07-2005, 07:19 AM
Hmmm... sorta reminds me of the lady who told the dealer that her car won't start after she gets a soft Vanilla Ice Cream Cone, but works fine with other flavours...

After many visits to the shop, a factory engineer finally accompanies her to the ice cream store. She goes in, buys a vanilla cone, comes out, and presto, her car won't start.

They get it going, then repeat the process, only she gets a different flavour -- the car starts just fine.

It took a long time before they figured out that the difference was time. The soft ice cream machine was in the front of the store, and lineups were short. A vapour lock would develop.

The flavoured hard ice cream, though, took longer to get (through the queue, as Sizzler would say), and longer to serve, so when she got back to the car, the lock was already cleared.

If that story is only half true, it's still a good one! :headbang:

Davo
07-07-2005, 12:24 PM
NeilM - so, what you're saying is I shoulda bought a Nautique with a MPFI... :eek: ...because, I don't think I'll have much luck getting a "factory engineer" out on my boat anytime soon. lol

rspiecha
07-07-2005, 04:22 PM
My 1994 Prostar 205 with the same 350 TBI 275 hp engine had the same problem. I talked with the service manager and he recommended removing the water/fuel separator and adding a inline filter back by the fuel tank. I did this and serveral other things, and my problem is gone.

Rob

NeilM
07-08-2005, 02:19 AM
NeilM - so, what you're saying is I shoulda bought a Nautique with a MPFI... :eek: ...because, I don't think I'll have much luck getting a "factory engineer" out on my boat anytime soon. lol


nope... just don't eat soft vanilla ice cream :D

Jimmer -- it's like 99% of the stuff out there on the World Wide Wasteland. Someone says it's true....

canada air
07-08-2005, 03:05 AM
thanks guys. i did notice if i let it idle for a minute or 2 it doesn't do it so i'm thinking it might have something to do with temp or slight loadingup of fuel. i am very happy with the mastercraft boat. i could spend all day pulling people if it weren't for gas prices these days. Hey neil hows things out your way. it has finally stopped raining out here in sask. last three days 27.30,26. and they say more to come.

JimN
07-08-2005, 08:51 AM
Chico- it will start and the electronics work fine at less than 11.5V- it drops below that every time it's cranked. 6.9 V is where the ECM goes into a hard reset but if your point is to make sure the battery terminals and other contacts are in good shape, then I definitely agree.

For anyone with TBI and hard starting issues needing the throttle open, remove the flame arrestor and look at the injectors to see if they drip after the key is turned off. Also, make sure the PCV valve is clean.

Another thing that makes a difference is heat soak. If the temperature is high and it has been run hard, open the motor box after shutting it down.

The TPS may be bad- it defaults to 12% throttle position under certain conditions but I haven't seen too many hard starting problems due to this. It also may be slightly out of adjustment but usually can't go too far with the limited range of the slot. I would be more interested in the fuel filter(s), any fuel line fittings(shut-off valve, anti-siphon, clogged vent and pinched fuel line) dripping injectors and the IAC.

redline
07-08-2005, 09:45 AM
Prior to the US Coast Guard permitting MC to put their fuel pumps in the the tank (where they belong) there was a struggle with vapor lock. What might be happening is that you are significantly loading the engine, creating heat and when you shut off, the coolant quits flowing. What happens is called a heat soak and in a V-Drive, there is no place for the heat to go. When you go to start, the fuel basically boils in the lines and there is nothing available to make the engine go vroooom. By moving the throttle forward, the ECM adds more fuel during the crank time. Usually 25% is all you need and you should NOT HAVE TO PUMP the throttle like in the old carb days.

MC's engineers approached the USCG in the early 90's with the request to move the fuel pump cause they knew this would be a problem. It took 8 years, but since the pump has been moved, we've almost eliminated all vapor lock complaints.

PV

Davo
07-08-2005, 11:06 AM
Good info guys - I appreciate it (canada air, I hope you don't mind me jumping in on this). BTW, mine is an '02 and the fuel pump is on top of/in the gas tank...

The dealer did focus on the IAC valve when I had it in, but never seemed to resolve the problem fully.

As far as "heat soak"...first, I have a direct drive and second, the temp only creeps up to around 180 degrees after I turn the engine off and, correct me if I'm wrong, but that doesn't sound like it would be hot enough to create the heat soak.

Basically like Redline said, I have to move the throttle about 1/4 of the way and once it fires I'll give it a very slight pump. The interesting thing is - I have to do this at cold start also...however, when it's warm it's almost like as soon as cold water hits the engine and it cools it idles perfect. Although, that could just be coinciding with it recieving the proper fuel...

I'll check for the dripping injectors and I'll look for the PVC valve. JimN, do I check for this drip immediately after running the engine?

Finally, here are some other details that I know will complicate things - I've got 440 hours and I haven't changed my fuel filter or my plugs yet. I know, I know - not a good idea generally, but I change my fluids religously and the boat purrrs like a kitten. Even the wife said this week that it's running smooth like a caddilac. :) I'll probably have the filter and plugs changed soon regardless, but I'm thinking those items are not what's causing the hard start.

Sooo, what do you guys think? Thanks again, fellas.

rspiecha
07-08-2005, 01:38 PM
Don't forget cap and rotor. Maybe spark plug wires.

Rob

JimN
07-08-2005, 07:26 PM
Davo- yes, right before you shut it down and immediately after. another thing you can do, other than actually checking the fuel pressure(which you haven't said anything about) is turn the key on before cranking, pause, then crank. This lets the priming cycle increase the pressure for the initial cranking. If the screen on the fuel pump is clogged, you'll have exactly the symptoms you are describing.

Redline- I thought the ECM would only increase fuel delivery with throttle movement after reaching idle.

canada air
07-12-2005, 02:01 AM
starting holidays tomorrow and i will test some of very important info you guys have provided.

thanks again, gotta love forums