how much rail pressure needed to start?

[Mikcon]

With a scantool (snap-on read under generic obd II) I was able to get 9500 or so psi. but truck still won't start.

If this is enough pressure what else could keep the truck from starting.

Thanks,

Mike

 

[WCounts]

If you got pressure and won't start the injectors are not firing.

Mine idles at 7000psi.

 

[SP Diesel]

You only need around 3-4K to start.



As WCount stated stock your truck should be in the 6k-7k range depending on outdoor air temp.

 

[Bob4x4]

With a scantool (snap-on read under generic obd II) I was able to get 9500 or so psi. but truck still won't start.

If this is enough pressure what else could keep the truck from starting.

Thanks,

Mike

Got gas?



I still get a lot of tow-ins with gas in the tank.



Bob

 

[Mikcon]

I have 1/2 tank diesel (not gas if you mean gas) I think you mean wrong stuff and thanks but nope.

Any way to fire injectors??

Am I right thinking my cp3,Fuel pop off valve,and lift pump should be ok if I have this kind of pressure just cranking the motor over?

Also do you think the injectors could have all gone south at once.

I thought it should start with one or two bad?

Anything else you can think of would be great,

I am willing to try just about anything.

call me if anyone has any ideas.

440-897-8121

or just keep responding to this post as I am checking it and the others alot!

 

[JasonCzerak]

With a scantool (snap-on read under generic obd II) I was able to get 9500 or so psi. but truck still won't start.

If this is enough pressure what else could keep the truck from starting.

Thanks,

Mike

did you remove the boxes?



The Juice, if the power is not plugged in will throw a code and not fire.



Remove all boxes.

 

[Diesel Power]

relief valve or injectors is your problem, im leaning on your valve being the problem

 

[JStieger]

Mine idles at 7000psi.

My 03 idles at 5500 psi - I wonder why the 04. 5+ idles at a higher rail pressure? More holes in the injector nozzles?

 

[Elite1]

Your valve that drains your fuel filter canister isn't open, is it? Just checking, been there done that! ;-)

 

[sag2]

9000 is more than enough to start. Generally you should only need over about 4000 cranking. If you are really at 9000 I would guess you might have a box that is fooling the system. I have never seen that high of pressure just cranking. Give it a shot of WD40 or something (be careful of the grid heaters) to see if it tries to fire up. Bad injectors can wash down the cylinders and lower compression enough where it will not start. If it tries to light off on the alternate fuel at least most of the cylinders are still good. The injectors fire on about 80 volts, so be very careful probing around on the connectors for voltage. I have never found a way to manually fire an injector because of the high voltage and amperage that the ECU needs to fire them.

Check with your scanner to see if you have a good cam and crank sensor signal.

 

[Mikcon]

I did take all boxes off. that was first thing.

Good news and bad news.

Good news today it fired bad news we did nothing else!!!!

My buddy has some computer software for trouble shooting and it was able to get into the can-bus.

We plugged it in set up everything we wanted to see and when he tried to crank it off to capture anything going on the damn thing started right up.

we took it back to his shop and hope to replicate the problem again.

It stinks now I am going to wondering everywhere I go if it is going to start or not if we don't find anything wrong.

Just a side note would anyone be interested in a "standalone" fuel computer that would give full control timming and deration injector pulse ect. I am going to post in the comp thread but we are thinking of doing this and then problems like this will not exist.

 

[JasonCzerak]

I did take all boxes off. that was first thing.

Good news and bad news.

Good news today it fired bad news we did nothing else!!!!

My buddy has some computer software for trouble shooting and it was able to get into the can-bus.

We plugged it in set up everything we wanted to see and when he tried to crank it off to capture anything going on the damn thing started right up.

we took it back to his shop and hope to replicate the problem again.

It stinks now I am going to wondering everywhere I go if it is going to start or not if we don't find anything wrong.

Just a side note would anyone be interested in a "standalone" fuel computer that would give full control timming and deration injector pulse ect. I am going to post in the comp thread but we are thinking of doing this and then problems like this will not exist.

I rememeber Comp49191919191 or someone writting something about a standalone, simular to the Accel DFI system for the Duacrap and Cummins.



It would definitlly be nice. The idea of piggy back systems is touchy because well, to many variables. Edge tst, and the others do a great job at it! they work well. but it's just hack-ish IMHO.



Personally, I would be for a total utter re-program of cummins' and dodge computers first before replacing them with something. If one can figure out how to tell the cummins and dodge hardware to rev this stinking motor up to 4500rpm. that would be cool.



BUT, if this computer replacement you speak of used stock dodge plugs and bolts to the same areas and all that so one doesn't have to re-wire half the motor. Then, heck, that's prolly eaiser and better then re-programming hardware that will be rather difficult to hack.



So what I'm saying it's a coin flip But the end result is the ideal result, total control.

 

[Bob4x4]

You might want to ck out your skim system(if equipped). On intermittant concerns don't rule out anything as a possibility.



Bob

 

[Mikcon]

BoB4x4 is this like looking for brass magnets??

I don't know what a skim system is.

 

[betterthanstock]

My 03 idles at 5500 psi - I wonder why the 04. 5+ idles at a higher rail pressure? More holes in the injector nozzles?

the 03 has 8 holes, the 04. 5 and later has 5 larger holes.

The lower the pressure, the longer it will last.

 

[WCounts]

My 03 idles at 5500 psi - I wonder why the 04. 5+ idles at a higher rail pressure? More holes in the injector nozzles?

I'm not sure what mine idled at before I installed the stage I cp3. But the first thing I noticed was more rattle at ldle after the install and that may mean with the added volumn the pressure at idle may be a bit higher.