My truck is "acting" up. Sometimes during start up.

[Kaspian]

😕My '99 Dodge starts fine in the mornings. However, around noon (when I go to lunch), or around 4pm (when I leave) it hesitates to start. It turns over just fine. It feels like it has plenty of power there. I do have to hit the gas pedal a few times to get the engine started though. The funny thing it doesn't do that in the mornings. Sometimes I park my truck at home on a friday and wont use it till monday morning and it starts just fine.😕 Is there anything I should try before taking it to the shop?

 

[exdeath]

Maybe check the cold start temp sensor output and fuel pressure, maybe even MAF. Air density and temperature are the only differences between morning and afternoon starting, so anything to do with temperature dependent enrichment/leaning or fuel vaporization (bad fuel pressure regulator for example can cause lower fuel pressure combined with higher temperature and boil & vapor lock the fuel) would be a good start.

Also if pressure drops rapidly after shut down, in addition to regulator, could also be leaky injectors puddling fuel in the cylinders causing a rich condition for the first few minutes of cranking until it flushes out but this would be true any time you start after shutting down, not just in the afternoon.

Having to hit the pedal excessively to get it started makes it seem like its overly rich on startup and needing more air flow to clear it out, so first and easiest thing might be to monitor fuel pressure while cranking, running, and most importantly, when you shut it off (does it hold or decay rapidly). Would make sense to start with difficulty in the same day after you've driven, but not over the weekend, as sitting over the weekend is ample time for such excess fuel to evaporate on it's own.

Any codes?

 

[woodie1]

Gotta agree with the cold start sensor idea.