For some reason my truck has trouble starting. I let it sit for 3 hours or so and it has trouble. I thought the lift pump might have been the problem so I put an airdog 100 on it. Runs great when it's running but still having the same issues. I don't think it's the injection pump because it is never short on power. Every now and then it will throw a puff of white smoke right when I start it but that is only when it's cold outside. Any ideas or suggestions? I've run out possible suspects and could really use some new ideas.

Some possibilities, weak starter, poor battery connections, weak batteries, small air leak. I would go with an air leak if it sits for a couple of hours and you have a problem starting again. Have you checked for codes? This would help us all to give you some suggestions.

Do you have any engine codes? If so you need to post them up so we can help you a little better. White smoke is usually unburnt fuel, could also be condensation if your in a humid area on a cold day

Do you have any engine codes? If so you need to post them up so we can help you a little better. White smoke is usually unburnt fuel, could also be condensation if your in a humid area on a cold day

I don't know where to check for codes. It's an 02 just like a base model. Matted floors, manual locks, manual windows, but it does have leather seats. How do I check for codes?

Do you have a check engine light on? Its been a while since Ive used it, but there is a key trick you can use to extract the codes. With the truck off,Turn the key to the on position and back off 3 times, (I think) and the last time you turn it to the on position your odometer should relay any codes you may have stored in the ecm. Someone correct me if Im wrong, my 98.5 does not have this option but I think thats how it works.

Ok I just checked for codes. It threw two: P PCU, and P ECU. Anybody know what those mean off the top of your head?

Did it say "done" right after? That probably means you have no codes. The ecu is your ecm and pcu is your pcm. If there were codes, a number would follow such as 0237 or 1693 for example. So you probably dont have a check engine light then, right?Next thing you need to do is get a fuel pressure gauge hooked up to read fuel pressure coming from the lift pump, I see youve got an Air Dog ordered so your on the right track. How about your grid heaters? Does the wait to start light stay on longer as the temp gets colder? If the grid heater isnt working properly that could also cause hard starts when cold.

Did it say "done" right after? That probably means you have no codes. The ecu is your ecm and pcu is your pcm. If there were codes, a number would follow such as 0237 or 1693 for example. So you probably dont have a check engine light then, right? Next thing you need to do is get a fuel pressure gauge hooked up to read fuel pressure coming from the lift pump, I see youve got an Air Dog ordered so your on the right track. How about your grid heaters? Does the wait to start light stay on longer as the temp gets colder? If the grid heater isnt working properly that could also cause hard starts when cold.

Yes I installed the airdog last Saturday and didn't have trouble with it starting for 3 days. But this past Tuesday It did it again. I have the whole triple pillar guage setup in the mail, gonna be delivered on Monday and will install them next weekend; fuel pressure, boost, and egt.

Ok so youve recently been into your fuel system, I would look there that definitely seems like the culprit. Look for any minor leaks or wet spots. If your new pump has those quick connect push lock fittings, make sure they are good and tight. The slightest leak will allow air in the fuel line and the fuel will siphon back to the tank. Then when you go to start, youve got air in your lines and you have to push the air out before the truck will start. As an example, when I installed a new fuel pressure gauge last year, I started having similar issues with hard starts after the truck started. I pulled the fuel gauge back out of the pillar and the fitting on the back of the gauge was just barely damp. Almost not even enough to get your fingers wet. But I cinched the fitting down a touch more, problem solved. My point is It doesnt take much at all to give you a problem.

Ok so youve recently been into your fuel system, I would look there that definitely seems like the culprit. Look for any minor leaks or wet spots. If your new pump has those quick connect push lock fittings, make sure they are good and tight. The slightest leak will allow air in the fuel line and the fuel will siphon back to the tank. Then when you go to start, youve got air in your lines and you have to push the air out before the truck will start. As an example, when I installed a new fuel pressure gauge last year, I started having similar issues with hard starts after the truck started. I pulled the fuel gauge back out of the pillar and the fitting on the back of the gauge was just barely damp. Almost not even enough to get your fingers wet. But I cinched the fitting down a touch more, problem solved. My point is It doesnt take much at all to give you a problem.

I gotcha. I checked all the push loc fittings right after the installation. But I have noticed that after my truck has run for a while I can smell diesel. And the whole block is dirty, and my oil pan is wet because I have an oil leak somewhere. But I haven't been able to figure out where the fuel could be leaking..

Well I figured out why my truck was having trouble starting! The #6 injector line was loose and leaking fuel. Starts just fine now. Thank y'all for your advice and your willingness to help. I appreciate it.

Turns out, that didn't fix the problem. It fixed it for about 4 days and since this past Saturday it has taken me about 15 minutes to get my truck started. I put it in the shop yesterday to have them diagnose the problem. I really don't think it's the injection pump because its never short on power. I'm actually kinda hoping its the injectors because I have been wanting to upgrade them to 75hp injectors but we'll see how it goes.

How did this work out for you? It sounds like an air leak. Very possibly the return line on the back of the head or the return tee at the back of the engine. Both of these are near the #6 injector . I had the samemproblem and new orings and a sealing washer took care of it.