Grid heater and what else is dragging me down?

[ISX]

Alright heres a video of my truck. Now here's what I want to find out. If you notice, the voltage is 11.7 while it runs initially, then whatever that something is lets up and shows the grid heater only drawing it to 12.2, then it lets off and 14v is seen. So what is the initial thing that draws it down to 11.7? Does the grid heater have 2 power levels?

Edited November 17, 2009 by ISX

[Mopar1973Man]

Yes... It does have 2 power levels... 2 grid heaters drawing 95 AMPs a piece for a total of 190 AMPs for both... Once going it uses just one grid heater to keep the air temp up...

[ISX]

Well isn't that just fancy. Is there a way I can set it to make them both stay on more because my advanced timing really hates cold air.

[LiveOak]

Well isn't that just fancy. Is there a way I can set it to make them both stay on more because my advanced timing really hates cold air.

I would suggest plugging in the block heater a few hours prior to use or plug the block heater into a timer to pre-heat the engine. Then the grid heaters won't come on or be needed for initial cold starts. This is what I do on both of our trucks. It saves many years of battery life as well as wear and tare on your alternator. The engine is MUCH happier starting up on an initial cold start after being plugged in too. :thumbsup:

[ISX]

Well I live upstairs at an apartment right now therefore plugging it in is almost impossible. If I did the extension cord would be so long I would end up with next to no heat. And it also isn't the engine temperature that seems to be doing it, the cold air just kills it with the timing advanced, it just smokes and smokes until you drive it, I think just having the grid heater settings bumped up will make it a little happier, but I'm not sure how to do it. I am thinking it works off of IAT.?

[Mopar1973Man]

Yes your correct about the IAT sensor is controlling it yes... As for what value to feed the IAT I'm not sure since there is no way of veiwing the information on the computer and seeing the temps the computer sees... If there is a way of bridging the two grid heaters together it might be a temporary fix...

[flagmanruss]

Just a couple of thoughts. Are you drawing intake air through the fender? If so maybe you could do a small modification to draw underhood air in cold weather. I don't know what your outside tempature range is but do you use a "Winter Front" to block some/all of the grill in cold weather. It makes a huge differance to warm up times. (About time to get mine out.) Here's the link to the Winter Front thread. http://forum.mopar1973man.com/showthread.php?t=29&highlight=cold+front Russ

Edited November 22, 2009 by flagmanruss
to add link

[ISX]

I got the winter front on, and I got the BHAF so it sucks in whatever heat is there I guess. I'm wondering if its a combination of the cold fuel and the not so warm air..? So many technicalities lol.

[Mopar1973Man]

Cold everything makes for poor performance period... Like from the information on my truck using ScanGauge II... My truck run optimial at about 100*F worth of intake temp, 195*F worth of coolant... But when cold and just starting out in the morning the engine got a hell of a timing rattle till the coolant temp and IAT come up. As for the VP44 system there is a fuel temp sensor in the pump to offset timing and fuel rates for fuel temp. how this all works I don't know since I've never found a way to read fuel temp. :rolleyes2: (Just what I need another gauge!)

[ISX]

I keep trying to figure out a way to rig up intake temp to my overheard temp gauge lol. Flip a switch and it goes through the other wires to the intake temp instead of outdoor temp.. I don't know much about temp sensors though, and the one for the outside is plastic crap so I doubt it would hold up if I somehow got it into the intake.

[Mopar1973Man]

I keep trying to figure out a way to rig up intake temp to my overheard temp gauge lol. Flip a switch and it goes through the other wires to the intake temp instead of outdoor temp.. I don't know much about temp sensors though, and the one for the outside is plastic crap so I doubt it would hold up if I somehow got it into the intake.

Ummm... It might... :eek:

MAP sensor on the left, IAT sensor on the right... Yes that cage is plastic...

[ISX]

What's the most yours ever reads?

[Mopar1973Man]

Ummm... About 167*F manifold temp on a 122*F day in Riggins, ID...

[ISX]

Well I'll be damned. Time to buy another temp sensor!

[guesswho512]

fuel temp for timing? could that be the "gremlin" in my truck. is the fuel temp in the vp or b4 it?

[ISX]

I'd say its in the VP somewhere. What kind of gremlin problem are we talking about here?

[Mopar1973Man]

fuel temp for timing? could that be the "gremlin" in my truck. is the fuel temp in the vp or b4 it?

Inside the VP44... There is a fuel temp sensor that is read by the FPCM (Fuel Pump Control Module). But that data is not delievered to any other sub system (ECM or PCM) so as far as I know of there is no way to read it. DRBIII or Cummins INSITE might be able to see it... :confused: