Engine stalls at 2600 rpm

[mplecture]

Has anyone experienced this problem. I was out this weekend and everything was running fine. Mid day the boat started stalling whenever RPM reached 2600 RPM. For a short period of time I could increase the throttle very slowly, 1 rRPM per minute and could get it to plane out and work fine, later it would not do it. Also could sometimes throttle past 2600 where it would stall and then catch again and then I would have to run around 4500 RPM.

I have new plugs and new fuel filter. Things I remember that I did that day, I had a problem with my speaker wires and reached underneath to pull the speaker wire out of radio and put back in. Also accidentally turned motor off while was in gear.

Any advice would be appreciated.

[PSullivan3]

When the engine was cooled down or when first started for the day did you have the problem then?

[mplecture]

Engine started fine all day even after the problem appeared.

I'm wondering if there is a throttle position sensor that went bad.

Also noticed the voltage was running low sometimes, <12V. I'm bringing the battery in to be check and likely replace. It is around 4 years old.

[PSullivan3]

Make sure the lanyard on the trottle is in place. you primed the fuel filter when you put it in. Were you messing around with MAS? Check ignition switch make sure conections are tight and clean.

[wakejunky]

Could be a MAF sensor. It helps determine the load of the engine. You can clean it with brake cleaner. May have to replace it. Make sure it is installed properly it is very easy to install backwards.

[wakehead]

I had a similar issues, and replaced a throttle sensor at a local Toyota shop for around $450, and it fixed it.

[mplecture]

How was it going to a auto service center, any problems getting them to look at it?

[wakehead]

It took me a while because no boat dealer will ever look at it. I happened to know the owner of the  Toyota shop. But if you call around and ask if they are willing to look at it, you should be able to find one. Better yet, befriend a mechanic, that will save you a lot of money.

[mplecture]

Had the local Toyota dealer change the TPS about 2 weeks ago and was able to get it out this weekend with no luck. Hope that it might be the MAS and after that will have to bring to a dealer.

I could not find the MAS on the website. Anyone have to replace theirs and know the part number?
 

[wakejunky]

Your description sounds like a possible throttle lever sensor.( this is not the same as a TPS, it is on the other side of the throttle body and is a much more common failure on the Lexus engine) Test it like this.

Remove air intake tube. Turn key to the on position. One person move the throttle lever. Second person watch the throttle plate. You will get one of two results.

1. throttle plate moves in relation to throttle lever --- Good
2. throttle plate moves only 25% and only at almost wide open throttle ---- Bad throttle lever sensor. ( part # 2206050020)

Part number for a MAF sensor is 2220420010. You can get Both parts off TMS parts or any Lexus dealer. reference 2000 LS 400 if going to Lexus dealer. You might (not positive) get the Throttle lever sensor at a Toyota dealership. Reference a 2000 Tundra V8.