Mopar1973Man

High idle is typically because someone has been playing with the APPS voltage and attempting to adjust to match the tag on the stock APPS sensor. Another thing that affects idle is ECT coolant temperature. The COLDER the coolant the higher the idle. You can verify this by a live data tool and check the ECT values.

A piece of cake... Less than one hour.

Try replacing the fuel pump relay in the PDC.

Possibly... P0381 code would tell there is a bulb problem or wiring problem to the bulb. There could be other codes like P0380 or P0382 codes which the grid heater relay have issues and not firing. The only other thought which I would call a long shot is the WTS circuit of the ECM is damaged. I've never heard of that happening.

You going to have to stop at a local part store and have them plug and read the codes. 1999 trucks don't have any means of reading codes. There is no key trick. you might be talking the cluster test but that light remains off in the cluster test because it's controlled directly by the ECM and not the cluster.

Any P0381 error code?

I got a PM from @W-T this evening asking me to give him a call. Sad to say that he's lost his home and belongings. He's still got his truck. He wants to let me know as well all of you that his alive and doing well. The fire and its complex nature its created is preventing him from being active on the website at this time. Like I told him we'll keep the light on for him and wait for him to return.

I've got to ask the question what was the cause of the failure in the first place? That is something that has to be looked at too.

Not you got me looking at the NOAA weather page to see when I get to go play next.

Something I'll pass along to you. Go out and find a safe place to go play in the snow. Parking lots, large field, etc. I'm not saying high speeds but build enough speed and then to hard turns or hard stops and then try to correct out of it. Get used to the feeling of the truck gliding, the feeling of the point of G-force it takes to break free to start sliding. Now every start of winter I go do this and it pays off every year. Now when the truck starts to give way or slide a bit no surprise to me I know the limitations and how just a light correction can make it track straight again. I've had my truck start to whip the rear end on a corner with ever so slight correction and a light change of throttle she straightens right up. MoparMom looked at me and said, "You handled that like a Pro!" as she was gripping the "oh crap" handle tightly. That is where 90% of people get in trouble is the feeling of the vehicle breaking free and gliding on the road surface and the first thing they do is stomp on the brakes in a panic trying to stop the wild ride which is now set in motion till the vehicle comes to a true stop now. Now if the fear doesn't set in your mind will react accordingly and correct the problem before its issue.

Auto don't have the anti-stall feature. Manual do have this feature. Fueling map wise basically the same. Idle speed is a idle validate switch that trigger the ECM to seeing that idle is set and uses a totally separate software for controlling idle. Once the throttle moves and shows throttling now the idle software is dumped and the ECM now follows the APPS values for fueling commands.

As they panic at 25 MPH in 65 MPH speed zone. Out here it's laughable I find all the oversized tire and lifted Ford's out running around and only rolling 30 to 35 MPH in 65 MPH zone because they have no traction and unstable. I buzz right around them and keep on hauling a comfortable 55 to 60 MPH. The funny part, I rarely ever use my 4WD. Most of my highway travels in 2WD only.

You going to need to run it on the street through the RPM bands and see how it performs. Be aware high cetane fuels will create an early ignition and high cylinder pressures. Your 30° max might be too high. There was one gent here that just blew a head gasket with 30° timing and had ARP studs already and about 70 PSI of boost.

Like I see roughly 60-65 PSI on the highway. Idle at about 35 PSI fully warmed. Anything about the stated minimums. Excessive high oil pressure is not good either being you take the risk of blowing out the plastic oil cooling jets for the pistons. This is one reason that cold startups Cummins suggest to allow the oil warm a bit before rolling so the oil pressure doesn't get too high starting out in the morning. Mind you the block heater does not heat the oil or the oil pan at all. All that is the same temperature as the outside air. The block heater only heats the coolant jacket. So the first minute or so the engine oil will pass there the oil cooler and rise to the coolant temperature.

Clue. When an engine gets quiet the timing is retarded. This tends to make me a bit worried and want to check for error codes like the P0216 code. even like my last VP44 when it failed it died with the P0216 code as well but it was stuck in full advancement it rattled and knocked badly. As timing retards engine gets quiet. This is because the fuel is actually igniting slower and later and actually doing it work after TDC. As timing advances the ignition of the fuel is happening before TDC so you start to hear the rattle as the fire starts the ignition BTDC and then pushes over the top and finishes with the power stroke. You might look at other factors as well. Fuel and cetane amounts. Higher cetane fuels are lower BTU's but ignite much faster. Low cetane fuel will have more BTU's energy and burn slower and later.

Oil pressure by Cummins specs. Require at least 10 PSI at idle (800 RPM) Require at least 30 PSI at 2,000 RPM.

Kind of like a Big O tire I fell in love with years ago and the quit making them.

I've gotta ask if you checked IAT and ECT temp values. Typically in stock form the timing is cranked up somewhere around 19 to 20 degree on a cold startup. Fully warmed the timing is back to 12.86 degrees. If the ECT or IAT are misreporting it might change the timing. Like MPG switch regards timing in the realm of 3 to 4 degrees from stock value as it warming up.

Nice... Fresh snow to play in.

You might want to update your signature.

I'm the odd duck in the pile that has been mostly NAPA parts without any issues. I've got both a 190*F thermostat and a 180*F which is installed currently.

I can see that during the warm-up period but after that point the viscosity is the same between 0w-40 (15.7) and 15w-40 (15.6) so there is no gains to be had after warm up. Just a point of reference for folks. 40°C is equal to 104°F 100°C is equal to 212°F

Very true. If your really offroad a bunch 35" or 37" would do much better for clearance. Again for some that do travel offroad a bunch yeah bigger tires have their merits. I can see trying to clear rocks and such being a needed thing. Be even with stock tire sizes so close at 0.65 or 0.7 inch difference that not a heart breaker. I can see where a 285's just way too much rotational mass where your 255/80 do just a bit better. All the years of running 235's not fair from your mark. Now for someone like myself, that is now committed to being a pavement pounder that -1.25 inch is a bonus with less wind drag under the truck. If was to be able to change the role of my travels I might consider going back to 235's again being that extra bit of clearance. Merits can be had in both directions just depending on what you plan on doing with the truck. Even in my day of back country travels and firewood hauling never really had any issues. Now being I run that BigTex trailer for firewood that even lower to the ground clearance wise. If the trailer will clear it the truck has no problem. I can also see the difference in the travels were you might be true offroad (I mean off the forestry roads all together cross country). That would require that kind of extra clearance.

What @AH64ID post is above...

Comparing... 255/80 R17 to 265/75 R16 basically the same width of tread. 255's are a 33 inch tire. From the ground up to the axle centers. 285/75 R16 - 16.4 inches. (+0.1 inches) 255/80 R17 - 16.5 inches. 235/85 R16 - 15.85 inches (-0.65 inches) 265/75 R16 - 15.8 inches. (-0.7 inches) 245/75 R16 - 15.25 inches. (-1.25 inches) 215/85 R16 - 15.20 inches (-1.3 inches) Not a huge difference till you get to the 245's which is an inch difference from axle center line down to the ground. Basically, you can travel in a whole 1.25 inches more snow than I can. Not a huge loss in my book.