Fixed my heater! But found a diesel leak...
 

I changed my antifreeze today and replaced my t-stat, now the heater works and the temp guage actually moves!!

Now for what I found....

Is it normal for the guage to near the half way point and DROP down to the first line? Not knowing how these trucks operate with a good t-stat I'm not sure what normal is, does seem weird to drop that fast.

I also found a leak on the injector pump and that a wire had come disconnected near the leak, actually opposite the wire, on the same cylindrical piece, big nut on the end, see arrow. If you look at the power steering pump it's possible to see the clean spot where the leak had been landing, has anybody had a leak here if so how did you fix (sorry for the vague description's but it's all I've got)[duhhh]

See the new blue connector, that was the disconnected wire.

Any ideas on what that wire does? After connecting it the engine comes down from idle slower, and seems to idle higher near 850 RPM or so.

Sorry for all the questions all at once, I'm a little obsessive about my truck working properly[laugh]

The temp gauge oscillates in my truck now that its gotten cold out. (It goes up to the half way mark, drops to the 1/4 mark, climbs back to the half mark and so on) I'm going to assume its the t-stat opening and closing.

Mine drops fast enough to catch my attention. Usually gauge needles plummeting isn't a good thing [laugh]

That is your KSB...it advances your timing during warm up and also when your at higher RPM's.

As for it leaking...I don't know if you can reseal it? I've torn apart my IP many times, can reseal it with one hand tied behind my back..but never had a KSB apart to see what makes it tick.[redface]

Hopefullly somebody here knows how to fix the KSB...

Temp gauge - last thread I read the needle should go to the second skinny line and hover in that area, little to the left, little to the right depending on what your doing. The plummeting gauge sounds like the thermostat is hanging up.

KSB - Take advantage of the fact that it's easy to get to and take it apart. Maybe just an o-ring or something. Sounds like an easy fix here:
https://www.dieseltruckresource.com/...light=KSB+leak

It's been a couple years, but it is either o-rings or crush gaskets. Take them to an auto parts store and they should be able to size them up. The tube has a crush sleeve. I had to replace mine because the tube was not through the sleeve when it was crushed.

Thanks jbawden for the link to the KSB leak fix.

Does any body else have the temp gauge that fluctuates like mine and gots_a_sol does?

want to remove the t-stat if I dont have to.

I've been around very few that don't fluctuate. Usually, the better sahpe the cooling system is in, the more fluctuation, at least in my experience. The issue, IMO, is these engines were built to work and work hard. Piddling around empty doesn't put much heat into the coolant, so you wait and wait and finally the t-stat opens and floods the engine with very cold coolant, hence the needle dropping. Said very cold coolant makes it to the t-stat housing and seeing this, the t-stat slams shut again and the temps begin to climb. Repeat ad-nauseum. The harder I've worked my 12v's, the more consistant the temp reading. Also, when the radiator was about completely plugged on my 89, the gauge was pretty steady. New radiator, tstat water pump and off to the races with the gauge!

Thanks G1625S that makes me feel better, I didn't look at the "jiggle pins" when installing the t-stat so I thought that maybe that was causing the flucutation, but it looks like my cooling system is working great!

My 91 will swing up to 2/3 during warm up, then settle just above 1/3. In the winter, it will settle around 3/8 with the winter front on. Without it, it will swing +- around the 1/3 mark. My 92 is a lot more stable.

[QUOTE=93 high hopes;2881985]Is it normal for the guage to near the half way point and DROP down to the first line?QUOTE]

That's exactly the way mine works.
It's more noticable when it's -30C outside as opposed to +30C but YES, you can watch my needle move with every cycle of the t-stat.