Engine/Transmission (1994 - 1998) grid heater and fuel heater question on '95

[LarryWard]

Central valley of Calif has been overcast with high fog for a week or more and daytime temps stay in 40's and no sun. For some reason starting has been less than quick as it usually is. So I noticed the amp guage still shows same draw after light goes off. On my mercedes wgn the gloplugs continue to heat up I am told after light goes off. And in colder weather it always helps to linger a while after light goes off. Truck does seem to act similiarly if I wait a bit. It definitely refuses to go without either repeated relighting the light or just waiting after lite is off a while. How does it work exactly? The issue may be something more than just cooler temps.



Couple yrs ago the fuel warmer connector seems to have disentgrated so I just pulled it totally away and was told it is only important in cold climate. But I prefer having things fixed since I might venture into colder regions. The end appeared to overheated from some cause. Any experience on this? Thks for suggestions.

 

[crabman]

LW,

The amp gauge will show draw(cycle) until the vehicle gets to app. 25mph.

Intake Manifold Temperature{IMT}=59*=0 seconds on Pre-heat cycle time(engine not running){PHC[enr]}=Post-heat cycle{PHC}(engine running) NO

IMT=15* to 59*F=10 seconds PHC(enr)=PHC=YES

IMT=0* to 15*F=15 seconds PHC(enr)=PHC YES

IMT=Below 0*F=30 seconds PHC(enr)=PHC YES

You can check to see if the relays and heater are working correctly.

TESTS

crabman

 

[Joe G.]

With those kind of temps I don't bother waiting for the wait to start light to go out. Just start it up. If it is hard to start your idle may be too low. I always start mine with a little pedal. Is your trans a manual or auto?

 

[LarryWard]

It is an auto, should put that in signature. And its true, it has started right off without a wait in the past when I absent mindedly cranked without a wait and learned how quickly it comes to life. Idle is a bit low as you suggest. Also will do those tests on relays and heater as suggested.



Does anyone want to comment on my fuel heater melted connection?



What is difference betwn "post reply" and "post quick reply" and "go advanced"? Not sure how to use-still learning.

 

[Joe G.]

Winter is not a serious business out here. Try it in ND and it's a different story. My fuel heater had a melt down too. I have some pictures of it in my Reader's Rigs gallery. I took it out some time ago. No problems. I don't think it's needed here at all. Mine has started in UT at 18 degrees. I forgot about waiting for the light to go out from force of habit I guess. It started right up. Banged around a little complaining about it. Smoothed out in a few seconds and all was well.

 

[Andy Redmond]

Larry:



Joe is right, its likely uncessary. We are discussing two things : Grid heater (air intake) and fuel heater. The grid heater is what pulls the amp gauge down, like to the tune of 300 amps potenitally. If you are attempting a crank in cold temps say no more than 10 below. Cycle the grid heaters several times, by putting the key in the run position w/out cranking, key to off then repeat, then a little go pedal and spin her over. I've cranked a 12v in minus 15 temps without the block heater. (no electricity) Some may have gone colder. Its much better for the block heater to warm everything up a bit in frigid temps (say less than + 15), but it is effective if the battery /batteries are starter are strong.



Fuel heater: Its purpose is the heat the fuel in colder weather to prevent gelling. As you are aware, much of the fuel is returned thru the pump and back to the tank even at road speeds. This circulation especially when "warmed" could certainly help prevent gelling.



I think Joe removed his heater all together? as it allowed an air leak. You can follow his instructions for by passing or order a new heater from Cummins or Dodge. The following are Cummins (Fleetguard part numbers) and the one that starts with a 4 is a Mopar number for the strainer kit.



4762962 3845400S prefilter screen kit

3834185S pre-filter, upper heater o-ring

3907766S heater element

3843722S cable harness





Good luck

Andy