I just drove the truck enough to get it warmed up, about 15mi, and let it sit for about 30 minutes, then went to start it again and it started hard, and the engine is warm, so now, it may be starting hard when warm also, it's about 60 degrees outside today. I put a code reader on it also today, and it shows NO FAULTS. I am going to put a new fuel filter on it and I have not changed out the new oil that I have in it yet, want to see what difference the new fuel filter may make first. The filter is about 5 years old, however, the truck has been driven only about 3000mi in that 5 year time period.

 

HOLY HELL BAD FUEL!!! That may be 90% of your issue, get some diesel clean or something in that tank now, more then likely there is a ton of water and algie in that fuel.

A normal code reader will not read our codes, need something a bit more up to date. IE, nothing Autozone has...

 

5 year old filter would probably have some pretty interesting things growing in it...

 

These pics are of the filter that I took out, and the new one beside it. What do you guys think? Does it look normal for a used filter, or worse? The housing that the filter fits down in looks clean and fuel looks normal and no water. I will look for a better code reader, I did use a AutoZone type reader. I also put some of that diesel fuel additive in.

 

Imo change the oil and either use an additive and get it used up or empty the tank and get some nice new fuel. And change the fuel filter of course

 

Yeah your filter was long overdue.

Did the fuel or filter smell like it had oil in it?

 

Well....after adding a fuel additive and changing the fuel filter (which was long over due), It appears that, that was my problem. After driving the truck to get the fuel additive through the fuel system, and then letting it sit over night, it now starts normally (it fires rite up).

Thanks all you guys for all the trouble shooting & diagnosing. I'm going to start a new post on my next problem (sounds like air is leaking or escaping from someplace under the hood when the transmission shifts "and" only wile I accelerator somewhat hard, If I take off slow, it does not make the leaking air noise during shifting).

 

I have been having a similar problem. My 2002 7.3 starts but looses power almost imediately and then stops. I finally get it started and it just "clunks" then idles but still no power. If I get it to rev smoke bellows for a short minute. This started during cold weather but when I plugged it in I had little or no problems. But now in warmer conditions it starts and idles right away but when I start driving in looses power and runs rough even after many miles. I replaced the fuel filter thinking it was the problem. But it still persists. I read this thread. I have 200,000 plus and use good fuel and Rotella. Any suggestions? Thanks.

 

my 03 7.3 runs rough until the engine warms up completly, takes 20-30 mins even in summer. what can i do or check to improve on this?

 

Do you know anybody with a scanner?