Hey guys,

My truck is having trouble starting on a cold start. It's like it will barely stumble up to 500 rpm or sometimes not even start. Sometimes when it starts I get a grinding noise which I think is coming from the starter? On the 2nd turn if it doesn't start the first time it starts crisply and powerfuly. As well, after that initial cold start if say I turn the engine off and then start it again it starts great like it should. It only does it when cold. I just recently put a new "ebay" starter in 3 months ago concurrently with the 6.0 swap (it appeared to be a genuine delco 6.0 starter). Up until about 2 weeks ago it started great since the swap. Could the starter be bad? Fuel pump? The truck is a 2000 with 145k on it. Thanks!

 

I had a fuel pump on the way out the door just after 100k miles. It didn't cause start up issues but I would look into that for yours.

 

You'd think though with a weak fuel pump it wouldn't run correctly, yet the engine still gets up and goes perfectly. I just don't understand why it stuggles to start cold, yet after that it works fine.

Maybe the battery is weak? I just had it tested a couple months ago and it's fine...and it's only about 2 years old. It should be good for 6. And that doesn't explain the random grinding sound either.

 

no battery wouldnt be the problem, and fuel pump or filter could be a possiblity starving for fuel but never heard a grinding noise from that,, that'd be starter if grinding

 

This may or may not help but....
Mine was getting where it would only start on the 2nd crank. I've been working on my VE table lately and it's starting on the first crank now. So you May want to look into that. But you could also have a problem with the Fuel Pressure Regulator bleeding off pressure.

 

one way you can test if its a fuel pressure problem is turn the key all the way to the on position, leave it for a second or two turn it back then turn it on, this will prime the lines to build pressure.
try turning it to the on position one or two times if it starts right up after that you have either a weak pump or something causing your pressure to bleed out

 

You know vicious, it's funny you mentioned that, all this seemed to start up after I put in a new wheatley tune....

95....I will try that!

 

There could be a bunch of things giving you the hard cold start, (weak battery, IAC valve sticking, fueling issues, etc.), but since this started happening after installing a new tune, I'd look at getting the tune tweaked first

 

I have an old tune I can stick in...

 

Perfect