Truck specs are in my sig.

I am having an intermittent start up problem.
When cold startup seems fine, then drive it enough to get it up to normal running temp,
shut it off and 10 minutes later go to start it up, longer crank time and sluggish startup.
It runs great once I get it started.

I have noticed that the idle is a bit low lately, at times.
Not getting a CEL

Looking for suggestions for where to start looking,
all help will be appreciated !

 

Something is getting warm, and having issues.... Trouble is, there are too many things that could potential cause it, cam or crank sensor spring immediately to mind. (leaning toward crank sensor.) You may have to wait till it gets worse before you can figure it out.

 

I'd say check your fuel pressure during hard start first. Next, look into the evap emissions circuit. A good place to start (forgive the punn) is to remove the gas cap n see if there is a giant sucking sound. Take the gas cap off n see if the pickup gets any easier to start. The evap lines may be clogged, disconnected or your vapor purge tank is full or raw fuel. Put your hand or some form of metal stethoscope on the evap valve and listen or feel for a clicking noise, it should click. If it's not clicking, then it could be stuck open and your gas tank is undergoing a slow n steady vacuum buildup during warmup operations and the fuel pump can no longer overcome the vacuum until it once again slowly bleeds off after sitting for awhile. Last but certainly not least, if the fuel delivery is good, check ye 'ol cat for clogging n peer down the intake thru the throttle body to see if your plenum floor is a swimming pool of oil.

 

Just got to thinking, this past December I replaced the TPS, got it from O'Reilly Auto Parts,
don't remember the brand, but it was one of the lower priced ones, could this have an effect
on starting and idle ?

 

Thanks, I'll look into all of that.
Not quite 2 years ago I installed a new Carter brand fuel pump from Rock Auto.

 

Carter is usually pretty good. I think Delphi, or Denso were what Dodge used from the factory.

TPS may play a role, simply checking the values show, when cold, and then hot, with throttle fully closed should tell the tale there.

 

Just give it a shot of ether! LOL. Maybe the IAC valve? You guys will probably think I'm nuts, but as old as our trucks are, we should just replace all the sensors and valves. We'd probably surprised at the difference.

 

It's been my experience that the TPS is either good, bad or has a bad "spot". I've yet to see a bad one myself, even in upstate NY. If you have a volt/ohm meter you can do a resistance check to rule it out, it'll behave like a potentiometer on an old analog style radio. It won't be effected by temperature. However, there's always a first time for everything.

 

Haven't been able to duplicate the problem again to this point.

Just stopped by the local parts store and picked up the stuff to
give the throttle body a good cleaning, a dirty IAC could be the
causing the slightly low idle and at 164,000 + miles , I'm sure
that it won't hurt.

Thank's for all of the replies, I'll keep this updated when I find
something out.

 

I'd dump a couple cans of Sea Foam in the gas tank also.