wont idle at all just dies 2009 silverado 2500hd 2wd gas engine

[theacguy]

I am having trouble and would like some help if anyone out their could spare the time.

 

 

so i was on the way home the other day on the highway doing 75mph i had a check engine light on for about one week. code p0121 TPS so i got off to get fuel and when i returned to the highway the truck would not go above 70mph. the more i pushed the gas the faster i decelerated. top speed was about 65 mph if i feathered it. so i made it home barley and the next morning it starts and goes to a few hundred rpm then quickly dies about two seconds after the starter disengages. so i reset the code p0121 and changed the air filter cleaned the MAF sensor and removed the throttle body. i cleaned the throttle body very well and the butterfly. i also changed the tps while it was off. reassembled it and same problem starts for two seconds and the idle wont catch it just dies. no high idle when it starts just average but does not run for more than two seconds. when i step on the gas within that two second window it just dies faster. i checked the fuel pressure at the fuel rail and it is holding about 55-60 when the engine starts but does not drop when the engine dies out. the truck has not trown any codes since the p0121

 

thanks for any time you might have to help with this.

[theacguy]

so 59 about is the steady fuel pressure while i try to start it even when it dies the fuel pressure stays the same what should it be at?

[Dnt]

AC compressor is locking up....just joking..... you have a bad cam position sensor just replace it and good to go.

[theacguy]

thanks i will try that and see whats up should have that changed tonight we will see and thanks for your time

[Dnt]

no problem man i am glad to help we have about 20 of those 2500's at work and i think everyone has had a cam position sensor installed to cure those exact symptoms after about 300k miles rack up.

Now since you are the ACGUY help me find a small leak in my 2009 Nordyne hybrid package unit. Up to this point I have been unwilling to tear all the panels off to access the evap coil my ZX-1 says it is not the compressor / service valves or cond coil area where you can actually check. GIMMEE ALL UR SECRETS LOL

[theacguy]

Well the camshaft position CMP sensor did not change the running of the truck. i am i'm thinking that the fuel pump is not working well the gauge that i used is not the best in the world. what are your ideas and why would the truck not throw any codes...

 

as for your air conditioning problem.. where are you located? i'm in the DFW area in texas. i'm pretty sure your evap coil is leaking if it is more than a few years old and it is a slow leak. you can tear it apart but the only sides that leak are usually the ends where the tubing bends and the very bottom

 

anyways if it is a slow leak it is more than likely in the coil and you need to replace it their is nor repairing it. ten year warranty on the new ones dont sweat it.

[theacguy]

also btw do you think it could be bad gas or some trash i picked up when i ran the tank down before i filled it up?

[last truck]

unplug maf and see if ot will run on default settings, didn't think the cam sensor would help, never replaced one yet and we have about 700 6.0s in my fleet. We do a quite a few crank relearns but usually after plugs and wires are replaced.

[Raptordude]

Could be the CRANK position sensor. That's exactly what happened to mine. It would crank up and rev up to 1,000 rpm or so upon start up and then just die. As you said, the idle wouldn't "catch" it at 500 rpm, it would just die

 

 

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[theacguy]

well i'm sorry to say that i have already tried to run the motor with the maf sensor unpluged i was sure it had a default setting for that and no change. i have tested the injectors and they are firing i can keep the engine running with brake parts cleaner in the air intake... i've got the truck in the shop now i would just be changing parts which i dont mind doing but i'm sure my mechanic can figure it out sad thing is that he doesent work on weekends and he will have it until monday at least. and i also never send him easy stuff haha so he will get a couple of hours out of me on this one but i'm usually on top of the easy stuff. thanks for the help and i will get back to you fellas and let you guys know what the issue was. I'm thinking it can only either be the computer which i think is most likley or may be trash in my fuel.

 

when you had a bad crank sensor mr Enthusiast did it throw any codes?

 

thanks for all the help

[Raptordude]

I didn't have any lights when it went bad, but I never tried reading the codes off it with a scanner

 

 

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[cameron24v]

Could it be..... The TPS????

 

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[theacguy]

well guys thanks for the help i'm glad we got it figured out it was finally discovered that their was bad gas in it no water in the gas and not to much ethanol but bad gas none the less