[chadcma350]

I was wondering how everybodys truck starts ,and if it is consistant every day,or it starts differnt every time you fire it up.
For example my 6.0 will some times start very fast like a gas engine half a crank and its on,and other times it is a crank or two like a normal diesl but it rarely will fire up the same way twice in the same day,i guess what im trying to say is that it isnt consistant like some of the gas motors ive had in the past,by the way the the start up weather is never below freezing so temp is not the issue,let me know how your rides fire! /ubbthreads/images/graemlins/smokin.gif

 

[stewcon]

About like yours. Sometimes fast but probably most of the time 2-4 seconds.

 

[OCOMOF05]

Mine cranks 2-3 secs when its cold in the a.m. Sometimes when I shut it off at operating temp. and restart it fires up instantly but not always.Alot of EFI gassers do this too.Rick

 

[Bumpy]

Same as you. At times fires up almost instantly others it cranks over a few first. /ubbthreads/images/graemlins/shrug.gif

 

[MikeL46]

Mine varies.

This morning it fired right up. This afternoon it took 4-5 seconds to catch.

Mike

 

[JESSE 1]

My truck starts up fast in cool weather. Acts different when it's been sitting for a while in warm weather. Only acts this way when it's been shut down for several hours. Engine will crank over fast but acts like it is going to stall out at the moment of starting. I'm going to get it into the shop to check this out but waiting for warm weather to do it. The tech will only have one chance to catch it doing the slow start.

 

[Fireferg73]

Mine varies as well. Seems to fire right up first thing in the AM after a long soak. Later in the day after its been up to operating temp, it cranks for 2-3 seconds. /ubbthreads/images/graemlins/shrug.gif

 

[BigGreenDiesel]

Wow, I guess I may be the only one to say that mine is 100% consistent, fires up the exact same , every time. /ubbthreads/images/graemlins/shrug.gif

 

[Supercrew632]

Mine is pretty consistant, but when it sits for a few days, tends to crank longer than ususal. I would say 2-3 secs. at the most.

 

[salterja]

Mine is pretty consistant at 2-3 sec.

 

[dbcraw]

I've neer paid al ot of attention, but most of the time it cranks a couple seconds before it starts.

 

[OMCUSNR]

[ QUOTE ]
I was wondering how everybodys truck starts ,and if it is consistant every day,or it starts differnt every time you fire it up.
For example my 6.0 will some times start very fast like a gas engine half a crank and its on,and other times it is a crank or two like a normal diesl but it rarely will fire up the same way twice in the same day,i guess what im trying to say is that it isnt consistant like some of the gas motors ive had in the past,by the way the the start up weather is never below freezing so temp is not the issue,let me know how your rides fire! /ubbthreads/images/graemlins/smokin.gif

[/ QUOTE ]

Gotta remember - its the oil.

These trucks require high pressure oil to fire the injectors, and it takes a second or two for the HPOP to come up to pressure. Starts are going to depend largly on how your oil is behaving. So temp is going to play some part, time shut down is in there, oil viscosity & quality, etc. are all part of the varibles in the starting equation.

 

[Zaphod]

I've always figured the difference in the start was due to the HPOP curcuit, too. I can't put my finger on it exactly, but it seems to me that if I leave the key 'on' a bit past the WTS lamp, it will fire up instantly most times.

Is the HPOP electric or belt/driveshaft driven?

It also might have something to do with how much pressure is left in the line from the last shutoff. Does the HPOP run constantly or does it switch on and off with pressure (or is it variable speed)?

Really, there are quite the variety of noises under the hood during the initial startup.

 

[AllOutFirefighter13]

Zaphod,

As OMCUSNR_RET said, it's all about the oil and HPOP. Leaving the key on past the WTS light will only let the glow plugs add more heat to the combustion chamber. This, obviously, will help for better starts in colder weather, but the ultimate factor here is the pressure of the HPOP. I used to know what the minimum pressure that was required to fire the injectors (I wanna say something like 500-700 PSI), and until this pressure is seen, the injectors will not fire. The HPOP is driven by gears that are located on the back (tranny side) of the engine. The camshaft is also driven by these gears. If the engine is turning, then the HPOP is turning. The HPOP has a "mini" oil pain located in the valley of the block that will hold almost 1 qt. of oil. Depending on where everything (all moving parts) is when you shut down the engine, the oil pressure could possibly bleed off a bit, although it's not designed to do that. I use Delo 15W-40 and get consistant starts when cold. When at running temperature, it can fire up almost instantly, or it can take 2-3 seconds. I've been told that if it consistantly cranks for anything over 5 seconds, then it should be taken in. The output of the HPOP is regulated to deliver the right amount of pressure to the injectors based on RPM, engine load, etc., and I've heard it can go as high as 30,000+ PSI. Now dont' shoot me if that's wrong, but my memory isn't the best. Hope this helps!!!!

Later,