Cold Engine Hard Start and Rough Idle

[Foster#17]

A buddy of mine has been having problems with his truck cranking a while before it will start when it sits and the engine cools down. When it starts, it will idle rough with no smoke for a few minutes and then clear up. What do you guys think this might be? He took it to a shop and explained what was going on. He said they hooked up to a computer and some of the injectors werent working 100% but they were still working... It doesnt sound like a very reliable shop to me. The guy didnt even check anything else on the truck and just told him to replace the injectors. (like come on, at least make an attempt to check over some other things) Im leaning towards injectors as well but do you think it could also be a lift pump issue? The truck is bone stock as far as I know and im wondering if the lift pump is failing causing it to not start right away and could be allowing air in the system or something. The CP3 might be having troubles getting the fuel sucked up from the tank if the lift pump is failing? He is bringing the truck to me this week sometime for me to check it out and im going to check his lift pump pressure and rail pressure, etc. He also has changed the fuel filter and had no luck with that. Any ideas or advice would be nice! Thanks!

 

[smokinVE]

I'd start by checking to see if it's not getting supply pressure, or it's sucking air on the supply side.

 

[zfaylor]

When my in tank pump was going it had these similar symptoms. Although it didn't matter warm or cold how it would act. One would think a failing lift pump would be more apt to work when cool. It died shortly after. They are really common symptoms of injectors though.

 

[Foster#17]

Actually I think its always hard to start but idles fine when its warm! Thats whats making me think its the lift pump!