2004 Silverado 2500HD wont start

[David06]

Ok I am looking for some help/info. I bought a 2004 Silverado 2500HD 4x4 with a 6.0 vortec engine in July. I drove it about 30 miles home and it ran great. A couple days went by and when I took it for a ride and it started stalling. I got it back home and it hasn't run since. Well it will run for a few seconds but then die. Ok so here is what I have do to it. First I changed the plugs and wires, still nothing. I checked fuel pressure and it rose to about 60psi but the imediately went to zero so I changed the fuel pump. Still nothing. Then I changed the crank position sensor, still nothing. Then cleaned the throttle body and nothing. Oh I forgot to say that I was at no time getting any codes on the diagnostic computer. After cleaning the throttle body I got a p0101 code(maf sensor) so I changed the maf sensor. Still nothing so I put a new throttle body on it. Now I get codes P0068,P0101,P0107,P0220,P1516, P2135 and the odometer says reduced engine power. And of course it will start to turn over but it will not actually run. All these codes pertain to the throttle body, maf, map and acceleration pedal position sensor but I am not sure where to go from here. Do I need to change the acceleration pedal position sensor and the map sensor? They are the only ones I did not change. Or do I need to tow it to a garage for some kind of calibration or just take the PCM in and have it reprogramed?I am really at a loss here, so any help would be appreciated. Also just an FYI this truck doesnt have a external fuel filter. It has a non servicable permanent filter in the fuel pump and the fuel pressure regulator is also on the fuel pump.

[MT-2500]

Originally Posted by David06

Ok I am looking for some help/info. I bought a 2004 Silverado 2500HD 4x4 with a 6.0 vortec engine in July. I drove it about 30 miles home and it ran great. A couple days went by and when I took it for a ride and it started stalling. I got it back home and it hasn't run since. Well it will run for a few seconds but then die. Ok so here is what I have do to it. First I changed the plugs and wires, still nothing. I checked fuel pressure and it rose to about 60psi but the imediately went to zero so I changed the fuel pump. Still nothing. Then I changed the crank position sensor, still nothing. Then cleaned the throttle body and nothing. Oh I forgot to say that I was at no time getting any codes on the diagnostic computer. After cleaning the throttle body I got a p0101 code(maf sensor) so I changed the maf sensor. Still nothing so I put a new throttle body on it. Now I get codes P0068,P0101,P0107,P0220,P1516, P2135 and the odometer says reduced engine power. And of course it will start to turn over but it will not actually run. All these codes pertain to the throttle body, maf, map and acceleration pedal position sensor but I am not sure where to go from here. Do I need to change the acceleration pedal position sensor and the map sensor? They are the only ones I did not change. Or do I need to tow it to a garage for some kind of calibration or just take the PCM in and have it reprogramed?I am really at a loss here, so any help would be appreciated. Also just an FYI this truck doesnt have a external fuel filter. It has a non servicable permanent filter in the fuel pump and the fuel pressure regulator is also on the fuel pump.

Proper testing before throwing parts at it,very hard on the old pocket book and or you will be buying another truck in parts.

As to that many codes clear all codes and see what comes back.
Also unkook neg cable for 5-10minutes and then hook it back up.
The neg unhook will not clear codes but may reset or unspike VCM.
Post back them code no.

Confirm every thing plugged back up and plugin's good.

As to no start confirm good fuel pressure engine cranking.
Confirm good spark to all plugs engine cranking.
Also confirm injector pulse engine cranking.
Get us know how it goes.

[David06]

I had already cleared the codes and the same ones came back also I tried unhooking the battery so the pcm would reset but that did no good either. It still does the same thing

[j cAT]

you should have come here first before buying any parts.

with the original problem no DTC codes, no start .

I would check fuel pressure 53-60 psi . key on engine off. pressure should very slowly drop. if rapid drop then this may mean a defective pump... could be a hole in regulator diaphram or leaky injectors flooding the engine. so the pressure guage goes to the fuel line out of the fuel filter/pump pre engine connection and see if the pressure holds with no fuel pump running .

the other item is the ECT is defective. this will throw no codes and cause poor/no start.
located on the head driver side forward near #1 plug...............

with the reduced power you have this is the throttle body drive by wire component. check you have the correct part could be this throttle body is junk .. the use of carb cleaner will damage this component. electrical parts get destroyed.

who made the fuel pump ? if airtex or not a delphi pump this would be a good reason if the pressures now are not correct.

[MT-2500]

Originally Posted by David06

I had already cleared the codes and the same ones came back also I tried unhooking the battery so the pcm would reset but that did no good either. It still does the same thing

That many codes points to VCM blowed or wiring and or plugins messed up or bad parts shorting thing out.
Strange codes started after parts replacement.
If you still have your old parts I would put them back on and start retesting.
On unhooking battery cabel?
Like unpluging neg cable first and hooking it up last?

I would also.
Go to the basis test.
Fuel pressure.
Good hot blue spark to all plugs.
Injector pulse.

Does a shot of carb cleaner help start it?
Are spark plugs wet or dry on ends?

[David06]

First the old stuff because I am still looking for some help/info. I bought a 2004 Silverado 2500HD 4x4 with
a 6.0 vortec engine in July. I drove it about 30 miles home and it ran great.
A couple days went by and when I took it for a ride and it started stalling.
I got it back home and it hasn't run since. Well it will run for a few seconds
but then die. Ok so here is what I have do to it. First I changed the plugs
and wires, still nothing. I checked fuel pressure and it rose to about 60psi
but the imediately went to zero so I changed the fuel pump. Still nothing. Then
I changed the crank position sensor, still nothing. Then cleaned the throttle
body and nothing. Oh I forgot to say that I was at no time getting any codes
on the diagnostic computer. After cleaning the throttle body I got a p0101
code(maf sensor) so I changed the maf sensor. Still nothing so I put a new
throttle body on it. Now I get codes P0068,P0101,P0107,P0220,P1516, P2135 and
the odometer says reduced engine power. And of course it will start to turn
over but it will not actually run. All these codes pertain to the throttle body
, maf, map and acceleration pedal position sensor but I am not sure where to go
from here. Do I need to change the acceleration pedal position sensor and the
map sensor? They are the only ones I did not change. Or do I need to tow it to
a garage for some kind of calibration or just take the PCM in and have it
reprogramed?I am really at a loss here, so any help would be appreciated. Also
just an FYI this truck doesnt have a external fuel filter. It has a non servicable
permanent filter in the fuel pump and the fuel pressure regulator is also on the
fuel pump. Ok now on to today. Turns out the throttle body I bought was junk so I returned it. I changed the pedal sensor and that did no good so I took it to a dealer and after 6 hours of working on it they have no clue as to why it wont start so I brought it home.The dealer was the one that said the throttle body was no good and they were right. when I put on a different one all codes went away, they also said fuel pressure and spark was good but I checked and cleaned all the gound connections that I could find and replced the ground cable from the battery. Still the thing will not start. Now all the sudden I have no spark. I checked at the plug and I checked 5 of the 8 coils. No spark from any of it. Is it possible for all 8 coils to go? Is there something else that cotrols the power to the coils? Anybody have any ideas.

[j cAT]

with the fuel pump working correctly having the proper pressure your no spark is now in need of troubleshooting.

this could be the PCM/computer. check all fuses there are many. use a voltmeter to see that they all have power. the fuse box is a good spot for rodents to chew on wires under the hood.

the coil has a pink wire. all the coils pink wires with the ignition on should be 12volts. check that out . this should go to inj 15a fuse.

if all the fuses are good and you have power to this fuse with no voltage at all the coils ,,,,then you must remove the fuse cover and inspect the wires under the fuse box and all those connectors. the wires are very small guage..

the black wire [at all the coils] goes to ground make sure it checks out with the meter/ohmmeter.

the pcm directly goes to the coil firing input.
with a crank position signal to the pcm it should get the coils to produce a spark.

post back what you found.

[David06]

I did replace the pcm but that didnt help any. I also checked voltage at the coils and got 11.7 volts and the grounds were good. I didnt find any blown fuses and the wires under the fuse box all look good

[j cAT]

Originally Posted by David06

I did replace the pcm but that didnt help any. I also checked voltage at the coils and got 11.7 volts and the grounds were good. I didnt find any blown fuses and the wires under the fuse box all look good

I am thinking that the cranksensor under the starter could be the problem. with the engine being rotated the voltage should go from 5volts down to 1 volt or so .

with the ignition on see that you do have 5 volts to it.

sometimes the encoder wheel inside the engine can cause this. rare .

disable the fuel pump first.