Hard Cold Start Problem

HySpdChiKnFeeD · September 9, 2009

Basic Info:

2001 1500HD /w 6.0L Vortec, 88,000mi

Problem:

The engine progressively starting having a hard start while cold. Sometimes it'd fire right up, sometimes you'd have to crank it over up to 60 seconds before it spit and sputter and took. Once it ran, it was fine and would fire up until it got cold again.

Took to GM dealership. They cleaned the throttle body clear back to the injectors. (Can give specifics off the bill if need be). Said that should have done it. While it idles better, and the truck def. has more spunk, it still has a cold start problem. They suggested using midgrade fuel, and trying different fuel companies.

They cant seem to figure it out, and are working on giving me a "Tell-Tale" device to run in the truck for a while.

Anyone ran into this problem?

On a side note, I also had them investigate why I would get a "Service 4WD" message on occation, but it wouldn't store the code, turns out it was the switch on the dashboard that needed replaced (should some of you run into this problem).

Thanks in advance!

ColoradoSkiCountry · September 10, 2009

I would suspect the Fuel Pump and or the Fuel Pressure Regulator. Same symptoms my 99 had and thanks to the suggestions from folks on here a few years ago, narrowed it down to the fuel pump. Replaced the fuel sending unit (which also fixed my faulty gas guage, another common problem) and it ran fine.

I would try this:

In the morning, turn it to the run position for a few seconds (not start) then turn the key back off, then back to run for a few seconds, then back to off. Do it one more time, then try starting it. (your more or less building up the fuel pressure by doing this) If it starts right up, then I would definitly say your pump or the FPR. Not sure on the 6.0, but for the 5.3, the FPR is under the hood, where as the fuel pump is located in the gas tank.

Did the dealer do a fuel pressure check?

RJG183SA · September 10, 2009

I had the same symptoms as you explain on my 03 6.0 2500 HD at around 40k. (hard cold starts). I ended up testing and replacing the FPR. It was out of spec by around 5 psi. IIRC this is a common prob.

Did the GM tech diagnos the FPR and or pump?

rodram · September 11, 2009

get your fuel pressure checked,,,, very likely the problem starting the engine is due to low fuel pressure.... I am not sure about the 2001 6LVortec, but the older 5.7LVortec requires 61 to 66 psi to function properly and there is very little tolerance for proper operation below 60psi.....

.. starting my 5.7Lvortec was a pain until I broke down and replaced the fuel pump....

HySpdChiKnFeeD · September 11, 2009

Not sure if they tested the fuel pressure or not.. I would assume they would have?

I can't even get a detailed list as to what they do for a 100,000mi tuneup that their willing to charge $600 for, let alone a detailed list of what they checked and didn't check.

I'll try that on/off technique and see what happens, thanks fellas.