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View Full Version : '01 LTR330 warm start issue


JLMax16
08-16-2012, 09:17 PM
In the past year or so I have been having a few intermittent issues that came to a head 2 weeks ago. I was having power issues, bogging with takeoff and (at a cruising speed) an erratic RPM. On top of those big issues I was also having problems with starting the engine after it had warmed up. Cold starts are stupendous. Here's what I have done so far:

Replaced Coolant temp sensor: From what I read, if this sensor was malfunctioning it would cause the motor to run rich, therefore only start (when warm) with WOT. *This was before the power issues.

Replaced Intake manifold pressure sensor: It was filled with oil and I also read it could be related to the starting issue.

Then 2 weeks ago the power issues started. After checking codes I found that I had a faulty TPS sensor.

Replaced the TPS and all my power issues and jumping RPM's were fixed! Stoked on that.
Also replaced the spark plugs while I was in there.

But while I was out testing the boat today I am still having the "must be at WOT for the warm motor to start" issue. I'm at a loss.

*Not sure if this is related, but while cruising at 2000RPM for 30sec the boats power would dip out and drop the RPM's to 1300 for about 7 seconds, then it would jump back up to 2000RPM (it repeated this cycle indefinitely), I related it to only having a 1/4 tank of fuel and the boat being at a high angle. I filled up with fuel and tried it again (for a short distance) and didn't have an issue.

Anyone have any ideas? The fuel is fresh, I also put in a couple cans of Sea Foam to the last full tank.

JLMax16
08-20-2012, 07:34 PM
nobody?

petermegan
08-20-2012, 08:30 PM
Sounds like it could be fuel delivery, are you sure you are not another fuel pump victim? Maybe check fuel pressures at the rail?

Gabe63
08-20-2012, 09:06 PM
I have seen the same or similar complaints in the fuel pump thread when the fuel line in the tank gets kinked or leaks. Can you tell me what part number is on your fuel pump? 71-299 OR 71-333.

JLMax16
08-21-2012, 03:03 PM
71-332s

JLMax16
08-21-2012, 03:53 PM
Also, I replaced my fuel pump back in '09. Was this fuel pump model number affected?

Brian B
08-21-2012, 05:15 PM
Do you have a fair amount of water in the back bilge? My LTR with North Star ingnition would do the surging this when water splashed the coils. Took everything apart, cleaned connections, put dielectric grease on plugs and all is better!

JLMax16
08-21-2012, 07:39 PM
I got stuck in a thunderstorm in Havasu a couple times, with 3 ft swells blowing over the bow. But these issues started before that. I'll check it out though, thanks.

BallBushing
08-21-2012, 07:57 PM
Check the transmission cooler (inlet side) for weeds. Had the same bogging issue, got progressively worse. Cleaned about a quarter size bit of weeds out. Fixed the problem

JLMax16
08-22-2012, 02:57 PM
Check the transmission cooler (inlet side) for weeds. Had the same bogging issue, got progressively worse. Cleaned about a quarter size bit of weeds out. Fixed the problem

How do I do that?

swatguy
08-23-2012, 09:52 PM
Jl do you happen to have the t stat number? Did u grab it from napa?

I have to replace mine on my Ltr

MC209
08-23-2012, 10:13 PM
fuel filter first try. and what type of fuel you running? could be vapor locking if to much ethanol in your gas... always run premo!

JLMax16
08-23-2012, 11:31 PM
Swat- I never replaced the thermostat, I did replace the coolant temp sensor. I'm not sure what vehicle I looked up to get it (it was a while back), but I did get the throttle position sensor by looking up an '88 yukon. I'm pretty sure it has a P# on the side of it though (sorry I'm not home to look at it).

MC209- Where do I get a replacement fuel filter for the bottom of Carter pump assembly? I only run 91 octane.

Sayiwont
09-03-2012, 12:32 PM
I'm having a warm start issue as well. My boat cranks and runs fine for about an hour then I will turn it off to change riders and it won't start again. It smells like its flooding. If I let it sit for a few hours it will crank back up and run. I've had it in the shop and they replaced the fuel pump and wiring harness coming off of it. Any ideas what it could be?

Brian B
09-03-2012, 12:46 PM
Main circuit breaker?

Sayiwont
09-04-2012, 01:29 PM
If it were the main breaker nothing else would work. My bilge ballast radio everything still works.

JLMax16
09-04-2012, 02:55 PM
I'm having a warm start issue as well. My boat cranks and runs fine for about an hour then I will turn it off to change riders and it won't start again. It smells like its flooding. If I let it sit for a few hours it will crank back up and run. I've had it in the shop and they replaced the fuel pump and wiring harness coming off of it. Any ideas what it could be?

That's what mine is doing. I have to put it in neutral and at WOT to get it to start, and it throws a lot of smoke which smells rich. I'm going to be pulling out the injectors in the next few days to get them tested.

Sayiwont
09-04-2012, 03:48 PM
fuel filter first try. and what type of fuel you running? could be vapor locking if to much ethanol in your gas... always run premo!

Could vapor lock occur if the fuel filter is inside of the tank. I thought it could only occur in external fuel pumps. Excuse my ignorance, how do you determine if it is vapor lock bc that sounds a lot like what I'm having. After it sits a while it will crank and run fine again.

76S&S
09-04-2012, 04:49 PM
You shouldn't experience vapor lock in a pressurized fuel system.

pkreusch
09-12-2012, 09:43 PM
I have a 330 hp scorpion that tends to vapor lock in the dead of summer. My boat comes from michigan and has an external fuel pump. I guess the northern boat builders dont really think about vapor lock. Fuel is sucked from the tank, through a water separator/filter (next to the hot engine). It is then routed under the hot engine to "cool fuel" system that uses the lake water already warmed up by the heat exchanger cooling the transmission lines (not sure why the water couldnt have been diverted into 2 supply hoses). Then its routed across the hot engine to the fuel rail via high pressure lines cased in some measly insulation. Anyway, I changed fuel pumps only to be aggravated again when I shut the boat down for a few minutes after taking a ski set. After replacing the tank to engine fuel line (another futile and expensive effort) the problem persisted. Needless to say, I diagnosed it as vapor locked fuel line. Ethanol fuel only makes the problem worst. Testing for vapor lock can be pretty dangerous so I DO NOT SUGGEST THIS METHOD!!! Having said that, I have a spare piece of fuel hose handy that can go directly over the fuel rail schrader port. When it happened, I removed the fuel rail scrader valve with a tire valve removal tool (some gas will spew out, this is where it gets dangerous) I was careful to absorb excess gas in a rag that I removed from the boat and had the boat out of the garage and it was well ventilated. I connected one end of the spare line to the rail scrader port, the other end was routed to a spare gas can. When the key is turned on (not to start, just to ACC), fuel will flow momentarily. It will take 2 to 3 cycles of the key, but if vapor lock is the problem, you will see air pockets coming out of the hose end in the gas can. If you get a steady stream of fuel out of the hose with no air pockets, vapor lock is not your problem (you'll need to cycle out about a quart of fuel). I have since thought about many ideas to combat the problem but have not implemented any good ones yet. One thought is to install a fuel shutoff solenoid and 2nd fuel pump at the schrader port connection that can be cycled on when the problem occurs; on hot days, to purge the fuel line of air pockets and hot fuel prior to startup. Hope this helps.