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

Thread Tools Display Modes
Old 09-25-2016, 12:53 PM
MikeR MikeR is offline
TT Newbie
Join Date: Jul 2010
Boat: 2001 X-30, LTR 330
Location: Southwest
Posts: 29
2001 X-30 with LTR 330 not making full power

Hi, I'm hoping for some advice on how to fix our 2001 X-30 engine (LTR 330 with Northstar ignition) and get it back to full power.

We have had the boat for a couple of years and it has always run well, but recently it has been lacking power in the hole shot and at open throttle conditions (see full detailed history below). Out of the hole we can't get RPMs above 3000 and I am sure it used to be able to do better than that. The engine has about 340 hours on it.

I've changed the plugs and wires, the fuel filter (in the tank), and we have (mostly) new fuel since we've put about 40-60 gallons in this season; but nothing has fixed the problem.

The nearest lake is a 2 hour drive, so it takes most of a full day to do a test-drive session.
Last weekend I got a fuel pressure gauge and a MEFI 3 Scanner (from OBD Diagnostics) to try to get some data to track down the problem.

The fuel pressure was at about 45-46 psi on key-up, and dropped to maybe 44-45 psi at WOT.

The sensor data from the scanner is below.

RPM = 800, coolant = 70 C, IAC Pos = 50 steps, Knock retard = 0; throttle angle = 0%; BPW = 2.44, Ign V = 13.6; MAP = 44 kpa; TPS V = .53; spark advance = 11.6 deg, 2 atm MAP = 80 kpa

WOT hole shot:
RPM = 3000; coolant = 70.3; IAC Pos = 114 steps, knock retard = 0; throttle angle = 76 deg; BPW = 7.26, Ign V = 12.9V; MAP = 95.9; TPS sensor V = 3.39; spark advance = 33.7, 2 atm MAP = 190 kpa

Other notes: on the WOT hole shot acceleration I think I heard a single muffled thump or bang from the engine compartment sometime during the acceleration, it might have been a backfire(?) It didn't happen all the time, but on at least two of the hole-shot tests I heard it.

Also in reviewing the data I took I noticed that the throttle angle never went to 100%. Usually it was around 76% to 80%, and I did see on one run it went to 90%. I'm not sure if I didn't quite get the throttle all the way down, or if the calibration doesn't require 100% to be reached, or if this might be indicative of a TPS problem.

From reading other posts on here it seems like the problem could be dirty/plugged injectors or possibly a problem with the Northstar coil packs?

These are getting to be expensive and time consuming items to replace "on a hunch", and I dislike just throwing parts at it. But when it takes me most of a day to do a test run at the lake I can't afford the time for too many different "trial and error" runs either. Nearest dealer is also a many hour drive away, so I'm kind of stuck with no easy solution.

Any thoughts or suggestions on what to try next/first would be greatly appreciated!

Detailed history (for those who've read this far already):

This problem started last season (summer 2015). It was a busy summer and we didn't get to use the boat until the end of the season when we took it out to a new (to us) lake at higher elevation than usual (2500') The boat ran terrible, idled rough, and had no power and ran really really rough under throttle. We could barely get the boat up to 18 mph.
As I said I was crazy busy so the boat sat all winter and spring 2016 we took it to a local shop. They tested it and said they couldn't find anything wrong.

So we took to to our usual lake at 1500' and the boat ran fine all day.
We also did another trip to a lower elevation lake and the boat ran all weekend (June 2016)

Then in August we went back to the 2500' lake and it ran poorly again-- idle was smooth, but power was lacking and inconsistent. Sometimes we could wakeboard and sometimes it couldn't even quite get to wakeboarding speed.

So I changed the plugs and wires (.045 gap per spec) and we went back to the 1500' lake. The boat ran a bit better, we were able to wakeboard easily; but still not enough pull in the hole shot to get a slalom skier up.

So I changed the fuel filter and got the scanner and fuel pressure guage and went back to the lake for the test run data I showed above. And we are still lacking power.

Any advice or thoughts would be greatly appreciated!
Reply With Quote
Old 09-26-2016, 09:38 PM
Fullpass's Avatar
Fullpass Fullpass is offline
MC Devotee
Join Date: Dec 2013
Boat: MasterCraft 197 Pro Tournament Team
Location: Northern Midwest
Posts: 1,308
Send a message via Yahoo to Fullpass
you can buy a cheap mechanic stethoscope..put on each injector one at a time and listen to the injector..the clicking noise the injectors make should all be the same as while the engine is running..of course..just putting point of stethoscope on injector body to test...going up in altitude..less air..engine could be running rich..is that 2500 abov3 sea level? Injectors can be dirty..can run Some STP Super Concentrate..in tank.. atomizer fuel better. NEXT Maybe MAP SENSOR. others can chime N
Reply With Quote
Old 09-26-2016, 10:06 PM
Fullpass's Avatar
Fullpass Fullpass is offline
MC Devotee
Join Date: Dec 2013
Boat: MasterCraft 197 Pro Tournament Team
Location: Northern Midwest
Posts: 1,308
Send a message via Yahoo to Fullpass
I would replace air filter..thinking mixture is rich…but what did your plugs look like when you changed them..where they black..sooty looking?

Last edited by Fullpass; 09-26-2016 at 10:32 PM.
Reply With Quote
Old 09-26-2016, 10:49 PM
Psgwake's Avatar
Psgwake Psgwake is offline
TT Enthusiast
Join Date: Aug 2016
Boat: 2007 X45 496 crusader
Location: Southeast
Posts: 438
Fire at plugs?

You could fake a lake at home and run some coil tests. Most of your advanced autoparts or autozones have loaner noid light kits or you could buy a cheap spark tester and check one cylinder at a time for fire. When you changed the plugs, did any of them look different then the others? (I.e. Black and sooty or white and crusty) You could also do a compression test at home, those kits are also available on loan at most autoparts stores. I am just thinking outloud here for process of elimination before you drive all the way back to the water. Fuel good?
Reply With Quote
Old 09-27-2016, 09:27 AM
Fullpass's Avatar
Fullpass Fullpass is offline
MC Devotee
Join Date: Dec 2013
Boat: MasterCraft 197 Pro Tournament Team
Location: Northern Midwest
Posts: 1,308
Send a message via Yahoo to Fullpass
Map Sensor

MAP Sensor allows the engine to properly meter the air/fuel regardless of altitude - hence going to 2500 foot elevation should not be a problem, if MAP input from sensor is correct..AND YOU HAVE A CLEAN AIR FILTER, NO VACUM LEAKS, GOOD ELECTRICAL CONNECTIONS.

If there is a fault with the MAP sensor or the readings the ECM is getting from it are incorrect, the engine will most likely run very poorly, lack power, hesitate, backfire, or surge. Sound familiar at the 2500 ft elevation

"When you turn the key on before starting the engine, the ECM takes the reading off the MAP sensor and uses that to calculate barometric pressure." The ECM uses barometric pressure as the basis for calculating fuel/air ratio.

The most common issues with the MAP sensor is a vacuum leak. Any kind of vacuum leak will cause the pressure levels the MAP sensor sees to be lower than expected. The ECM responds to the vacuum leaks by making the mixture rich, should look at the spark plugs at the 2500 ft level..probably black and sooty

CHECK:Cracked/deformed vacuum hoses. Pull each hose off and bend them, look for cracks in hoses. Should only be two vacuum hoses. One smaller hose going to the top of the fuel pressure regulator on the fuel rail, the top of the fuel pressure regulator kind of goes up under the air intake engine plenum, can reach your finger up under their to make sure its connected, the hose goes directly into the side of the air intake manifold, Next to that vacuum hose is the Second and larger vacuum hose going to the PVC valve going to the valve cover

The map sensor it self is located on the back of the air intake engine plenum beside the throttle body. Checking the electrical connection, clean - no corrosion, electrical connection tight.




You can also check the throttle body bolts, should be three bolts, check that the bolts are tight, just snug, and that the throttle body gasket looks good intact. Also the engine air intake plenum bolts on top of the engine are snug. The gasket between the air intake plenum and air intake manifold are good and intact.

Hope this helps..my off hand diagnosis

Last edited by Fullpass; 09-27-2016 at 07:41 PM.
Reply With Quote
Old 10-02-2016, 02:37 AM
MikeR MikeR is offline
TT Newbie
Join Date: Jul 2010
Boat: 2001 X-30, LTR 330
Location: Southwest
Posts: 29
Reporting back on things, I checked with the MEFI scanner and the TPS was cleanly going from 0% to 100% very repeatably (without engine running), so decided it is highly unlikely to be a TPS issue.

I put in a bottle of Valvoline Fuel Injector cleaner into the gas tank and we went back out to the lake to try another test run. Once launched it started up just fine and I let it idle for at least 5 minutes while I tried to listen to the injectors. (I forgot the Harbor Freight stethoscope at home (!) so I had to resort to the tip of the long screwdriver on the injector with my ear on the handle) It wasn't as good as a stethoscope but I could definitely hear clicking through the screwdriver. One particular injector seemed to sound different, although it was a bit hard to tell since getting the screwdriver and my ear angled correctly was tricky. I poked around a bit more, tried unplugging the spark plug wire on that cylinder (engine rpm dropped and sound changed about the same as unplugging any other cylinder). I went back and listened again and the injector sounded normal! (So I'm not sure if it changed or if I just mis-heard it several times earlier.)

So we took the boat out on the water and it ran pretty well. We were able to pull up a skier on a single ski, and seemed to have plenty of top end speed. We only had 3 people in the boat instead of the usual assortment of kids and friends, so it is a bit hard to gauge, but overall it seemed to be running fairly close to full power if not back to full. So at least we got a great skiing and wakeboarding session in as part of the test drive

I'm at least 50% expecting the problem to come back -- since it's been kind of intermittent all season -- but in the meantime we are going to enjoy the end of the season until it does act up again!

It seems hard to believe that just a bottle of Valvoline Injector cleaner in a tank with probably 40-50 gal of gas would make the difference, but maybe it did.

Thanks fullpass and others for all your suggestions -- if (or when! ) the problem comes back I've got all your suggestions to look back at, and I'll report back on what happens.

Final note: I dug through the old spark plugs I had pulled out when I changed plugs and wires a couple of weeks ago. As I took them out in the engine bay I had looked at each and thought they looked OK; so thought nothing of it. However, on a closer look today in full daylight (out of the engine compartment) there was one that had significant dry black deposit and another that had a little bit of black deposit. Unfortunately I lost track of which went where

When I've got a couple more hours on the new plugs at the end of the season and I winterize I'll pull the new plugs and see if I see anything amiss.

Thanks again everyone!
Reply With Quote
Old 10-02-2016, 12:11 PM
Rossterman's Avatar
Rossterman Rossterman is offline
MC Devotee
Join Date: May 2012
Boat: 2001 prostar 205V
Location: Westcoast
Posts: 1,136
Several have found that the coil packs had delaminated and cracked causing some issues with intermittent sparking to,ground. They looked perfect but when they removed them, you could see the cracked case and where they were discharging to the block. Might want to look up the earlier post or pull them off and inspect them to be sure they are OK.
Reply With Quote
Old 10-02-2016, 12:57 PM
mikeg205 mikeg205 is offline
Super Moderator
Join Date: Aug 2011
Boat: 1995 Pro Star 205 5.7 Liter
Location: Plainfield - Joliet, IL
Posts: 18,085
Send a message via Skype™ to mikeg205
could be bad gas - best thing to do is pull plugs and post a picture... plus 1 on the coil packs.. those need to be inspected and clean. no stall and start indicated cranks sensors working ok. ICM could have issues as well.

Bad gas can cause issues as well and the injector cleaner may have cleared a chunk of varnish etc..
...A bad day water skiing still beats a good day at work...1995 Pro Star 205....
Reply With Quote
Old 09-08-2019, 10:53 PM
paintpollz's Avatar
paintpollz paintpollz is offline
MC Devotee
Join Date: Oct 2014
Boat: 2002 Prostar 197
Location: Fort Worth
Posts: 2,082
Bump. Does anyone know the OP or what the fix was with this boat

Please and thanks
Reply With Quote

2001 x-30, low power, ltr 330, wot

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 06:37 PM.