Hi all,

New to this great site. I have a 2002 quad, 4.7L, 108K. I've had a lingering problem for about a year now, and it's really driving me crazy. When the temp is below about 20 degrees, she starts right up at the turn of the key, every time. When its above about 20 degrees, and if she's been sitting for more than about 15 or 20 minutes, she has to crank a long time to start. So far (knock on wood) she has not failed to start, but it takes awhile. Once started, the idle is very low for about five seconds, then it lumbers up to regular idle. From there on out, she runs 100% fine. If it's above 20 degrees and she has not sat for more than 20 minutes, she starts fine and runs fine. Immediately after the rough start, I smell gas outside the engine compartment.

What I've done so far: The fuel pump has been replaced, but I'm convinced it wasn't necessary. Since that time, I've done all of the fuel pressure diagnostics in the service manual and she checks out fine. I replaced the TPS and the IAC valve, and have removed and cleaned the throttle body until you could eat off of it... all passaged and ports. I checked the operation of the Intake Air Temp sensor, and the Engine Coolant Temp sensor, both seem to read fine at low and normal temps.

I thought maybe injectors are coming into play, but it runs really well once she's started.

Any ideas?? I would greatly appreciate it!!!!

 

What are you calling a long time to start? 10-15 seconds, 30, a minute?

 

Thanks for the reply. I have to crank it three or four times, 5 to 10 seconds each time.

 

smelling gas means its not being burned. How do the plugs look?

 

i would think it be ur spark plugs try new spark plugs and wires. also if that dosn't work try a new starter? should fine a decent one at a junk yard

 

ok, this is a little weird but it sounds like something is causing your fuel to loose prime. Since you are smelling fuel outside the engine bay after this condition I would look to some form of leak. Take a good look at the schrader valve on your fuel rail, make sure it's good and tight with a cap on it.

 

I change my plugs frequently and the ones in there only have about 15K. This problem has bridged several plug sets. I have not, however, changed the coil packs. I haven't really suspected the plugs, coils, or starter because it shows a very strong temperature dependency.

I will search again for fuel leaks. So far I have not been able to find one. Again, if it were a leak, it seems strange that it would be so temp dependent.

It's not throwing any codes, but in a few weeks my brother will visit with a good scanner. We'll take a look at the real time pcm data and see if it yields any clues.

I've seen this (or very similar problems) discussed in the past, and most of the return posts point to the fuel pump. But I know from experience that it pays to check the fuel pressure first. The pump job is either very arduous, very expensive, or both.. and not necessarily the culprit!

I will post my solution if and when I find it. If you have other ideas to check in to, please let me know. Thanks!

 

I searched for a fuel leak today, but just can't see anything. The fuel rail is dry as a bone.

Any ideas?

 

check your fuel pressure, after you shut off the truck and when you start it back up, i am thinking your injector or injectors are stuck open and is flooding that cylinder. that would cause the hard start after leaving the truck off because their is no pressure and that the cylinder is flooded witch will cause the rough idle and the gas smell.

 

Thanks for the reply. That makes sense, I'll look into it! It would be nice to finally get this thing figured out.