AGD03Dually

Thanks John,Does the heater only function below certain temperatures, or does it momentarily cycle on and off with the ignition switch prior to the computer getting signals from all sensors?The reason I am asking this, is that I was just checking the relays with a test light. The side that connects to the battery has power as it should, however the other post is not getting energized when the key is turned on (I had someone to turn on the ignition switch while I held the test light on each terminal).Also is this controlled by the MAF/ATS?Am I wrong in thinking that it might be something other than the injectors?

I will put the Baldwin filter in.Does anyone know what the operating temperature of the Grid heater should be? It seems to me that a 15 degree variance would not be sufficient enough to start, especially when the temperatures are below freezing. Also it seems to me that the heater would more or less need to cycle on and off to some degree with lower temperatures during cold weather driving for engine performance / fuel efficiency, (sorry ADD kicking in). Maybe I'm just over thinking the problem. :think:Thanks to all that have tried to help!

Now I'm confused . The place where I bought my injectors said that is what they use in everything and that it was the closest to Cummins specs as you can get for replacement. This mornings results Air temp 41 degrees Key off Engine block 129 degrees Fuel Filter 65 degrees Intake heater 100.5 Key On All temps stayed the same. Lift pump ran for 2-3 seconds Started with 3-5 second crank cycle. Any thoughts?

The fuel filter I installed was a 44-FF010 ProGuard D2 F/F purchased is a replacement for the factory filter.

Ok, here is the info. Purchased truck in 2007 with 52,000 miles. It now has 108,000 miles all stock no add on's. I found out upon disassembling that all 6 injectors had been replaced. 3 had reman dates of 2005, 3 had reman dates of 2007 (apparently just prior to me buying it in July 2007). Now as of today, other than the info in my first post. I used a laser thermometer to check temperatures prior to trying to start it. Fuel filter housing 39 degrees Intake heater 38.5 degrees Key on; waited for glow plug lamp to go out (there was also a clicking noise under the hood next to fire wall that continued for close too two minutes. I waited for it to quit prior to trying to start. Not sure what this is I've never noticed it before). Intake heater now @ 52 degrees. 15 second crank cycle and started let run for a few minutes and turned off. Restarted and had a 3-5 second crank cycle Drove to job site turned off for 1 hour Started with 3-5 second crank cycle Went to next job and it sat for 5 hours and started with 3-5 second crank cycle. I will plug in the block heater tonight and recheck temps prior to starting. If all goes the way I think, it will start in 3-5 seconds. - - - Updated - - - Also forgot to mention that the lift pump was also replaced prior to pulling injectors (wishful thinking).

I have pulled all injectors and had them tested. #1 & #6 had high return flow. I replaced the two with high return as well as installed a 3 micron fuel filter, it started fine the first few days ( I have driven less than two hundred miles ), until the nights started getting cooler (<50 degrees), and it started with the long cranks again (multiple 20 second cranking cycles). If I plug in the block heater it starts in 3-5 second crank cycle. After driving I can shut it off any time and it starts within 3-5 second of cranking, just not cold. Prior to all of this I have Never had to plug in the block heater. I also, do not get any codes :banghead: