Am I on the right track? Water temp sender replacement

[dba4life]

Hello

1994 Sport Nautique with 5.8L ProBoss EFI

Symptoms -
1) Water temp guage on dash is dead
2) Boat will not start cold. Turns over and over but will not fire. Removing the air filter shows no fuel from the injectors is being dump in. Once the boat is started once for the day it starts everytime. I spray some starting fluid in before the first startup and it will start fine.

After getting some advice I decided to first try the water temp sender

Talked to Skidim and got part number 1237
http://www.skidim.com/prodinfo.asp?number=R020014

I pulled out my existing water temp sender (Right behind the thermostat housing). Picture I took of what I took out:

http://static.flickr.com/46/194434519_5754101d7f_b.jpg

As you can see it does not match up very well with the new unit. It is also the wrong size to fit in the whole. Does this sender go anywhere on my engine or do I just send it back?

It looks like I need part number 1234 to replace the water temp sending unit. Which is much cheaper:

http://www.skidim.com/prodinfo.asp?number=R020003

Waiting for a callback from Vince but I thought I would run this by this group in the meantime.

Thanks
Kevin

[dba4life]

RE: Am I on the right track? Water temp sender replacement

Just heard from SKIDIM.

They said the water sending unit is on the left side of the engine looking at it. So they are sending me that unit (1234). They said the water temp switch (1237) that I got is the right one and it goes on the right side of the engine when looking at it.

Given my symptoms should I replace both? Or just the water temp sending unit (1234)?

Thanks

[chill99]

RE: Am I on the right track? Water temp sender replacement

What does a water temp SWITCH do? Just curious, as I've been messing with some temp problems on my '92 SN.

[DavidF]

The TBI engines have a water temperature sending unit sensor that operates the temperature gauge. They also have a water temperature switch which acts like a choke for the TBI system. The switch senses water temperature and signals the ECM to provide a rich fuel mixture for a cold engine. As soon as the sensor is satisfied, the fuel mixture is return to normal. The gauge sending unit is located in the intake manifold and the switch is located on the water circulation pump.

A bad switch should not stop the injectors from operating cold or hot.

[nms1991]

Davidf accually there is a ect( engine coolant temp sender, two wire in the intake) that is for the ecm to use for the choke function,but there is a temp switch which is used to put the engine in to limp mode if it over heats and on the tbi engine it is under the thermostat housing in the circulating pump, and the temp sender for the gauge is in the intake manifold on the opposite side of the ect.

[DavidF]

Maybe so, I think my '95 engine only has the sending unit and CT sensor, but memory could be wrong. Either way, the sensor with the brown signal wire (and black ground wire) is the sensor that controls the ECM.

Another thing to note is that the ECM will only pull in the fuel pump relay when a 300 rpm cranking signal is present. So, if the battery is low and the engine is cranking less than 300rpms then the fuel pump AND injectors will not operate. By priming the engine, it fires thus increasing rpms above 300 and the fuel pump and injectors will then operate. This is, of course, after the initial (5 seconds or less) fuel pump operation with key on.

[dba4life]

OK - Replacing the water temp sender (1234) did not fix the temp guage on the dash. It is dead and does not move at all.

What should I test next. I went under the dash and confirmed all the wires have good connections and there is power to the guage.

Thanks

[Johnsongc]

DBA-

Not sure if this will help, but I had a dead gauge on my '01 Ski as well. Replaced it and it works great. However, my friends '99 nautique was being sent into "limp mode" and after a few test, we found that the signal going to the temp gauge was actually be provided by the sensor that sits under the thermostat housing on the top of the main water pump (which was also the reason it was being sent into limp mode). It is interesting to note that we disconnected all the sensors (one by one) in this thread and this was the only one that killed his gauge. Sorry I can't be more specific with the different names of the sensors but it looks like (from nms1991) that it is the engine coolant sensor that fixed the problem for my friend.

[dba4life]

What is the best place to get an exact replacement temp guage that matches the others? CC dealer?

[Johnsongc]

I went through West Coast Correct Craft. For about $30, they got me an exact duplicate. I am sure all of the dealers have them.

Greg

[dba4life]

Cheaper then I thought - Thanks

[dba4life]

Whitelake said VDO guages are no longer available. Quick search here verified the same thing.

I am trying to match these guages (Pict attached). Cannot find anything that has black needles.

Any ideas?

[dba4life]

Well this was as close as I can find. White background. Black outside bezel. Black needle.

http://www.boatersland.com/far-12904.html

Unless somone knows of a source for the originals I think I have to go with this one.

[dba4life]

Upon closer inspection tonight these gauges are the teleflex gauges. Date 1991 on the very bottom of the front. Anyone know if these are available anywhere?

Thanks and sorry for the confusion.

[dba4life]

As one final test this morning I ran a wire from the top of the new water temp sender at the engine directly to the guage in the dash. Just in case there was something wrong with the factory. No effect. The needle does not move. Guage has proper ground and 12v connected.


Looks like the Teleflex Lido series is the closest match. The bezel does not match but I am thinking of painting it black.

http://www.greatlakesskipper.com/pro...;ProductID=783