Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Engine / Drive Train

Reply
 
Thread Tools Display Modes
  #1  
Old 07-13-2012, 10:21 PM
jmhjgh jmhjgh is offline
TT Regular
 
Join Date: Apr 2010
Boat: Mastercraft,205,1996
Location: Midwest
Posts: 66
Prostar 205 engine surge issue

I posted last year about our 96 PS205 having issues with surging. The boat is up north and is not used much. We had codes for TPS sensor and that has been replaced. The boat now does not throw any codes. Last year the boat would run perfect up to 3200 rpm and then surge. We could pull the kids skiing and tubing but not adults who wanted to ski faster than 30. Now, the boat will rev up to full throttle, but will cough for a second before it settles down (almost like turning engine switch off/on). Pulling a skier, the boat will cough every 10-15 seconds in an irregular pattern. The fuel pump inlet is clean, and I replaced the fuel filter today. I am wondering about a fuel line leak or sucking air somewhere (I will check the intake manifold tomorrow). The shut-off valve on the top of the tank does not feel good opening or closing and I wonder if it should be removed/cleaned/replaced?
Also, coming off plane, the engine does not immediately go to idle speeds. It wants to rev at 1500-2000 before settling down to idle in 15 seconds. What else should I check?
Reply With Quote
  #2  
Old 07-14-2012, 09:45 AM
mikeg205's Avatar
mikeg205 mikeg205 is offline
Moderator
 
Join Date: Aug 2011
Boat: 1995 Pro Star 205 5.7 Liter
Location: Plainfield - Joliet, IL
Posts: 11,213
Send a message via Skype™ to mikeg205
Check the fuel vent in back to make sure its clear...friend had a cocoon in there... and was causing a suction issue. Is the spark(flame) arrestor clean?

How old is the gas? What do the plugs look like? Take a look at the distributor and rotor to make sure it's not fouled...

my .02....
__________________
...A bad day water skiing still beats a good day at work...1995 Pro Star 205....
Reply With Quote
  #3  
Old 07-15-2012, 12:08 PM
jmhjgh jmhjgh is offline
TT Regular
 
Join Date: Apr 2010
Boat: Mastercraft,205,1996
Location: Midwest
Posts: 66
fuel vent is clear and we ran without flame arrestor. Watched both fuel injectors cut out when it coughs. I think I need to buy a fuel pressure gauge.
Reply With Quote
  #4  
Old 07-15-2012, 12:15 PM
mikeg205's Avatar
mikeg205 mikeg205 is offline
Moderator
 
Join Date: Aug 2011
Boat: 1995 Pro Star 205 5.7 Liter
Location: Plainfield - Joliet, IL
Posts: 11,213
Send a message via Skype™ to mikeg205
TBI? maybe fuel pump connection is loose...or fuel pump starting to give you warning signals. Not a tough replacement... just a thought. TBI pressure is low... fuel cutting out is a different issue...could be also a bad ECT - does it do it when it's cold? JimN and Jmcrieght would have better insight than I.
__________________
...A bad day water skiing still beats a good day at work...1995 Pro Star 205....
Reply With Quote
  #5  
Old 07-15-2012, 10:42 PM
jmhjgh jmhjgh is offline
TT Regular
 
Join Date: Apr 2010
Boat: Mastercraft,205,1996
Location: Midwest
Posts: 66
Yes, TBI. Pump connection looks good. I tried to put my meter on the pump leads to see if the pump voltage is also cutting out, but there isn't much room. I might need to make an extension. ECT should be good, and if it wasn't, the limp mode should only be cutting out one injector not both. It seems like I am missing something easy. I checked the distributor voltage (purple/white wire) and it stayed around 1.5-1.7VDC and when it coughed, it looked like the voltage went up to around 2 VDC, but it never went away.
Reply With Quote
  #6  
Old 07-15-2012, 11:25 PM
Double D's Avatar
Double D Double D is offline
MC Maniac
 
Join Date: Sep 2004
Boat: 1994 Mastercraft, ProStar 205, 350 Indmar with 275 hp
Location: Massillon, Ohio
Posts: 4,239
My only addition to this is do not ignore the ECM or computer. My Engine surged a bunch after 20 minutes of use and viewing the injectors the fuel would sputter on one. It proved out to be the injector driver in the computer was bad. I currently run both injectors off one driver and it's fine. If this ends up being the problem and both injectors are sputtering, then a computer replacement would be in order.

My $0.02....


Sent from my wife's old iPad using Tapatalk....
__________________
If its not a competition ski boat, its always second best.

1994 MasterCraft ProStar 205
275 HP 350 Chevy Indmar
Monster Tower & PerfectPass

Check out the MasterCraft Buckeye Bash on Facebook!

"In my many years I have come to a conclusion that one useless man is a shame, two is a law firm and three or more is a congress." - John Adams
Reply With Quote
  #7  
Old 07-16-2012, 09:54 AM
jmhjgh jmhjgh is offline
TT Regular
 
Join Date: Apr 2010
Boat: Mastercraft,205,1996
Location: Midwest
Posts: 66
I remember reading your post a while ago. I would like to be able to confirm the ECM is bad before replacing. I was able to borrow a marine scanner and all seems to be in order electrically, but I am not sure what is happening when the injectors cut-out. It does seem to be changing because last fall, the engine would run perfect to around 3000 rpm, and now we get the injectors cutting out anywhere in the power band.
Reply With Quote
  #8  
Old 07-16-2012, 10:22 AM
Double D's Avatar
Double D Double D is offline
MC Maniac
 
Join Date: Sep 2004
Boat: 1994 Mastercraft, ProStar 205, 350 Indmar with 275 hp
Location: Massillon, Ohio
Posts: 4,239
Quote:
Originally Posted by jmhjgh View Post
I remember reading your post a while ago. I would like to be able to confirm the ECM is bad before replacing. I was able to borrow a marine scanner and all seems to be in order electrically, but I am not sure what is happening when the injectors cut-out. It does seem to be changing because last fall, the engine would run perfect to around 3000 rpm, and now we get the injectors cutting out anywhere in the power band.
Agree 100% about confirming computer is bad before you drop ~$800 on a new one. However, I am not sure how you do that since both your injectors are sputtering. My advantage was only one was sputtering and I could switch the lines to confirm it wasn't an injector, etc. Good Luck!!
__________________
If its not a competition ski boat, its always second best.

1994 MasterCraft ProStar 205
275 HP 350 Chevy Indmar
Monster Tower & PerfectPass

Check out the MasterCraft Buckeye Bash on Facebook!

"In my many years I have come to a conclusion that one useless man is a shame, two is a law firm and three or more is a congress." - John Adams
Reply With Quote
  #9  
Old 07-17-2012, 12:24 PM
jmhjgh jmhjgh is offline
TT Regular
 
Join Date: Apr 2010
Boat: Mastercraft,205,1996
Location: Midwest
Posts: 66
Do you think a bad fuel line could stop both injectors temporarily? I would think bad lines would slowly slow the boat, and not behave like someone is turning the ignition off and on. I need to tow the boat home so we can run some more tests.
Reply With Quote
  #10  
Old 07-17-2012, 01:38 PM
Stx221's Avatar
Stx221 Stx221 is offline
TT Enthusiast
 
Join Date: Jan 2012
Boat: 1995 Prostar 190, LT1 w/ Powerslot
Location: Maine
Posts: 189
Another thing to look into:
What does the oil pressure gauge look like when under way? Is it all over the place, or does it get up to about 30psi at idle and 55-60psi under load?
If it bounces all over the place, I recommend a new oil pressure sending unit. I know I was having a similar issue with the fuel pump power being cut on and off and it was due to the ECM "seeing" low oil pressure due to a faulty sending unit.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 06:57 AM.