New problem. 80k. Maintained. Truck intermittently requires an extended crank time when starting cold- long enough you think "it is not going to fire" and then it starts. It only happens now and then, and only when sitting over night. Ideas? I do not know if it is related, but the fan clutch goes to full engage when started cold and then takes a while to disengage- never did that before either.

I thought STC failure was indicated when warm starting issues appeared. Could this be the STC fitting or unrelated?

Thanks in advance for your ideas.

-Mike

 

Could be a couple of things...any codes? Are you running OEM filters? Recently I've been letting my truck go a couple of seconds (5-10) past the glow plug light going out. The extra heat helps when the engine is stone cold.

 

Have you done the "Blue spring upgrade"?

 

zhilton: It is not cold enough outside to matter. Besides, it is getting warmer and this is a new issue. OEM filter. But I did wonder if oil draining out of the canister could be the problem. My guess is no because even after an oil change, it spins less than now before starting.

chetspencer: I did the blue spring kit 1-2 years ago. Nothing indicates that my fuel pressure is low. -Mike

 

Subscribing. Been having similar issues...

 

FICM related on a hard cold start would be the first thing I looked at.

 

(bump)... Where are cheezit and bizmic (sp?) when you need them! -Mike

 

My long crank time was solved by repairing an HPO leak. It was a very slight leak, but enough that the oil would bleed down while sitting, and then had to reprime before it would reach 500psi and start.

They don't always leak only when warm.

Do you have a Scangage or Insight? Either of these monitors can let you watch the ICP and injector pulse width, and you can get a pretty good idea if this is your problem.

 

What are the normal number ranges for ICP and injector pulse width when using SGII? What number ranges would indicate a HPO leak? Thanks in advance,

Rob

 

You can find references for normal ranges in threads in the tech folder.

However, with a slight leak like mine, those won't be much help. It takes a pretty good leak for the IPR% value to be significantly out of range. In my case, the leak was only enough for air to enter the system while the truck cools and sits for a while. The leak was too small to positively hear using the shop air test. My truck never failed to start. It just started taking longer than normal. Like 4-5 seconds of crank.

But I could see it by watching the ICP pressure while cranking. The pressure would be very low for a few second of cranking, and then it would spring up above 500psi, and once it reached that minimum threshold the engine would spring to life. By watching the injector pulse width, I could also see that the PCM was not turning the injectors on until the ICP had reached that magic 500psi. Once running, ICP# and IPR% were within normal range at all temps and RPMs.

After the work was done, we still could not be sure that my STC fitting was leaking. It was marginally sloppy. But we could definitely see that the standpipe O-rings were eroded and leaking.

Now that the system is repaired, my ICP pressure begins to build with the very first turn of the crank and builds steadily above 500 within a second or maybe two seconds. And I am back to a normal 6.0 crank time, hot or cold.

 

thanks for that!

 

Thanks Bill. I really appreciate your taking the time to offer advice. -Mike