A splash of anti-gel additive might be an order. Your fuel is waxin up on you. Maybe not a strong enough blend of kero-diesel at your local station too. Run some additive of your choice as long as it has antigel properties.

 

well i'm updating a little late sorry bout that , as far as i can tell the preheater is doing what it's suppos'd to do, i have'nt had any trouble with gelling fuel or really had hard starts ,except when i don't plug it in an it hits 0- sometime soon i should have the wattage of the heater put up

 

The spec for the original heater is 2.5 to 3 ohms, cold. So, at 13.7 volts, that is 75 watts on the high side. The new heater that I just got from Genos measured .9 ohms at about 15 degrees F, or about 208 watts.

These fuel heaters use PTC, or positive temperature coefficient, ceramic heaters that are self regulating to a specific temperature range. When the heater temperature reaches the specific range, the resistance of the heater rises dramatically, as is shown in this graph:



The original heater was supposed to heat the fuel to between 43 & 53 degrees F, and I would assume that the new heater is similar (as 40 degrees is close to the magic temperature for "unclouding" straight #2 diesel wax particles).

As for antigel additives, I always run lubricity additive, but I don't like to overuse antigel, and sometimes I get surprised by a 0 degree night that I thought was going to be in the teens . . .

Many thanks again to Nathan, for posting about his installation!

 

Just for what it's worth ~ http://haisleymachine.com/product_in...oducts_id=2535

 

1. The daily high temperature has been below 32 degrees for the past week in Atlanta and my truck is parked outdoors -- I'm guessing my fuel heater in running full time? (The voltmeter on my dash appears to indicate something is drawing extra power full time.)

2. Other than the engine dying, how would one know the fuel heater isn't working properly?

Again, I apologize for the hijack.

TIA

 

Great post, Alec!

James, once the fuel in the tank warms up to the target temperature, the fuel heater basically shuts down. So on short trips in the weather you're having, the fuel heater will be heating the whole time. Drive for a couple hours and the fuel will have been warmed enough by the heater and the injection pump and the fuel heater won't be doing anything anymore.

Your voltmeter should not be down because of the fuel heater. It pulls about 6 amps at full power, the alternator should he no trouble keeping up with it.

A wax plugged filter is how most people find out it's not working. You can check it with an ohmmeter (do it cold) if you suspect it doesn't work. If it's an open circuit, you know you have a problem.

 

Hey thanks for this info guys, I just replaced the gasket on my fuel heater. Didnt have the luxury of waiting for a second gen one so I used the oil filter gasket number you provided works great so far!! Also, tip to get your filter stud out.... two 16 x 1.5 nuts. cut one in half run em on snug em up and back it out!!! Wish I could find the thread were that guy needed some advice to get his out...

 

As an update: For the first time in four years, I let the truck sit outside in about -5 F weather overnight, and was able to run it in the morning without the fuel filter plugging. Two mornings in a row. Fuel from my usual station.

I installed the 2nd gen heater a couple of weeks ago. Nathan very kindly helped me get a new plug -- I THINK it is a Metripac 280 style connector, 15300027 body. Also a NAPA # ECH EC147 might fit.

I installed the heater with the plug facing toward the injector pump, which allowed me to skip shaving off the housing, but did require a couple of inches of extra wire.

Everything worked well, and has been working well, including these last two mornings which I think count as an actual test.

 

Wow guess I'v had my head in the sand, Alec thanks for putting up the info on the heater , I been preoccupied lately with some other crudSorry guys ,ebteckx the oil filter number was for the second gen heater but it'll work on the first gen cool Alec sorry bout not getting back to you on the part numbers for the plug I'v got'em I jist have to go dig'em up NOTE IF ANYONE DOES THIS MOD AND CAN'T FIND A PLUG PM ME ad removed ALEC THANKS FOR PUTTING UP THE INFO YOU DUG UP THANKS MAN

 

All right I got off my duff and got the part numbers ; the plug =Pac;15300027 / the gray seal =Weatherpak silicone seal gray Kd86916 the metal connecters =Pac;12129493 these should be at any semi truck dealer ad removed

 

As an after thought you DO NOT HAVE TO MILL THE PREHEATER when I was talking with Alec he told me that if you turned the preheater so that the plugin was [roughly] facing the timing case, that it would go right on. You may have to turn it back and forth a bit to have it fit right. Jus thought i'd put it up

 

Well I thought I'd add my 2 cents since I've finally decided to hook up the wiring for the fuel pre-heater...now that it's friggin cold.

Anyway I tried to find the connectors that was listed...the Pac 15300027. I could not find the blank connector and my parts guy was eventually able to find a complete unit, with pigtails, through AC delco.

Here are a couple pics...





As you can see the ACD# is PT247 and the GM # is 12101855

Hope this helps other out.

 

Great timing, I was looking for this thread because I need to remove the heater for other issues and was going to replace with a 2nd gen if it was not working. I was hoping someone posted the connector numbers. Thanks!

 

That AC Delco PT247 number cross references as a General Motors truck door lock connector from 1988 to 2008. Can you say junk yard???

 

Thanks for looking that up!

The parts guy couldn't tell me what it was for, and I was in a hurry so didn't care. Cost me $20 so I can live with that. But being able to grab the connector for next to nothing from the wreckers is preferable in my book.