air temp sensor

[allison xtb]

How do you check it and where is it?
Thanks
Gary

 

[chad202]

Motor?

 

[ragtopvet]

If it's your 260 its below the starter,2 pink wires i think. U can check it with a ddt. Mine went out and was telling the computer it was 28 degrees when it was 89,it didn't run good at all. Randy Sawyer in clinton is a very good merc mechanic if u need someone with a ddt.

 

[chad202]

two tan wires and you can check it with a multimeter set on ohms.

 

[ragtopvet]

Any body know what the ohms ought to be for ambient temp?

 

[chad202]

Mine are tan.

 

[ImbadBob]

Ohms at 90 f were 11450. In the garage 14000. This sensor is for an early analog 260. I checked the sensor on my spare 260 that is digital and it was bad. 1.5 megaohms.

 

[allison xtb]

Sorry guys for the lack of information I guess I was in a hurry to start vacation(260hp). I found the sensor thanks to you guys. It checked 11.8K at 90f in the garage probably good. The problem is I ran the boat on about a 5 mile run. When I brought the boat home unburned fuel was dripping off the lower unit from inside the cowl. I checked the things Roy suggested (thanks Roy)and the sensor was one of them. I did add zipp ties to the hose that comes from the horn to the ecu because it was not real snug at some connections. The fuel appears to be coming from between the horn and the JSRE spacer. Not sure it is but there is a drip there.

 

[K-DAWG XB 2003]

So, If I am reading this correctly the air temp sensors for analog and digital at different?

 

[99hawk]

Does anyone know what the part number is for the air temp sensor on this 260 pictured above? My dealer can't find it for mine. It is a one wire sensor.

 

[FlatOutAlly]

A one wire 260 temperature sensor? Are you sure? The sensor in the picture above has two wires like every one I've even seen. Post a picture of your powerhead if you can.

 

[FlatOutAlly]

I think I see now. If you're talking about the one wire sensor in the right cylinder head, that's the temperature sensor for a temp gauge. This sensor does not affect engine performance. The temp sensor that the box reads is below the starter. Two brown wires.

Post a picture of your powerhead, if you can.

 

[99hawk]

Yep, I posted for the wrong sensor. Water temp sensor is what I was going for, though I've noticed people calling them head air sensors. Sorry for the confusion. Next time I will wait a while before I post after a heavy night of drinking. I'll post a pic.

 

[99hawk]

Meant water temp sensor

http://i822.photobucket.com/albums/zz150/785rmk/Allison%20XB%202003/GEDC0377.jpg

It hasn't worked since I have had it. So far with all the flooding here my xb has been an expensive swimming platform. Taking it to the Ozarks over labor day and want it to work properly.

 

[h2oskiier30]

Hawk, that is a head temp sensor. That's the one that feeds your ecu. It doesn't work the gauge. The one going to your gauge is fed from the port side head. It's also a single wire that's all tan (no blue tracer). It plugs into the tan wire coming from your key harness by the 8 pin connector.

If you're talking about your temp gauge not working since you've had it, it's because you need another sensor on the other side feeding it.

 

[FlatOutAlly]

 

[99hawk]

Thanks guys. Does anyone happen to know the part number for the optional sender?

 

[FlatOutAlly]

.......That's the one that feeds your ecu. It doesn't work the gauge. ........

As one should be able to see from the schematic, this is untrue. The box does not monitor head temperature, only ambient using the two wire sensor under the starter or on the front of the horn, depending on the vintage of the 2.5 EFI.

 

[h2oskiier30]

Yep, my fingers typed quicker than my brain...Meant to say that the tan w/blue tracer on the starboard head activates the hot horn. The tan wire from the port side head sender feeds the temp gauge, as I did say correctly.

 

[FlatOutAlly]

Yep, my fingers typed quicker than my brain...Meant to say that the tan w/blue tracer on the starboard head activates the hot horn. The tan wire from the port side head sender feeds the temp gauge, as I did say correctly.

Bingo!!!! Houston, we have synchronization!!!