6.0 rough start and rough Idle
 

Hey guys its been awhile..........

2004 f250 85,000 miles
arp head studs OEM gaskets
90hp over injectors
new hpop
airdog
fuel regulator spring upgrade
sct with tunes from Eric
full EGR delete
Tested the FICM

Its cranking a little to much to get fired up and runs like it has a damn lope tune until the oil temp reaches 100 degrees. After that it will run smooth MOST of the time. Sometimes it will still idle weird but no where near what it is under 100 degrees. I dont think it is a high pressure oil problem because when its hot its fine....... Oil temp and Coolant temp run at about 180 175 usually about 5 degrees off from eachother. Fuel pressure is always above 60. Not sure what else to check?? Had it hooked up at the dealership and another shop. They say nothing is wrong but i know better. Any ideas???

I would hook up a scanner when its cold. let sit overnight and first thing in the morning, do an injector buzz test and listen to the injector clicks all should sound the same

Well was any of this work done recently? Who's injectors, and what the heck is a 90hp injector? Most are given in cc ratings, ie stock is 135cc, upgrades are 155cc, 175cc, 190cc etc.

It says new HPOP, was that just put in? What oil are you using and what oil filter? What's your fuel pressure? Probably need to monitor ICP desired, ICP actual, and IPR duty % to see what is going on.

HPOP was put in about 3,000 miles ago. Im holding 70 psi fuel and all motorcraft filters. Rotella T oil. They are 155cc injectors from river city. I know the injectors are good but just looking in other directions now.

You do? Were they built from new injectors? This wouldn't be the first time I've heard of issues with RCD injectors... I remember watching some youtube vids of a very unhappy customer with issues exactly like what you're saying. How old are the injectors? I'd be getting a cylinder contribution test done myself.

After 3k miles, the HPOP should be fully bled by now. You could monitor ICP desired against ICP actual, while watching IPR % duty cycle as well. That would tell you if the high pressure oil system is working correctly, which I suspect it is because it gets better as it gets warm. If there was a leak or air, it'd be opposite of this.

Out of curiosity, how old are the batteries? I would have them load tested. Also when you tested the FICM, did you test it in all 3 conditions? Did you test it cold or warm? It really should be tested cold. This sounds like classic FICM issues, which if you say is good, then it's classic injector issues.

I recently had a similar experience. Yours may not be the same, but I thought I would throw it out there.

I was experiencing longer crank times to start my 2005 6.0, and rough running until it warmed up. I too assumed it was a temperature issue. Finally one day my truck started slow from cold, ran a bit rough, and died after a couple blocks and wouldn't restart.

It was towed to the nearest Ford dealer. It wasn't throwing any codes and it really confused them. They were able to get it to stall one more time, but no code.

Turned out that even though my batteries tested fine, it was the batteries. Apparently these things run on the batteries for the first couple minutes. My batteries were marginal, but apparently strong enough to run things until my dual alternators kicked in and starting charging them back up. I was somewhat skeptical, but after two new 850CCA batteries the truck starts faster, and runs better right from the start.

If your batteries are old like mine were it might be worth considering.

That sounds like it could be the problem. Its got two different batteries in it. They were in there when i got it. Im walking out to the truck now to look and see if i can find some dates on them and will be taking them to get tested tomorrow. Ill keep you up dated.


Ill be the first to tell you RCD has horrible injectors and even worse customer service. Ive never dealt with a place like that before and will never again. All the shops around here are dropping them. BUT, they were just buzz tested a few weeks ago and both places ive went have told me the injectors are working fine. They were installed about 6 months ago and ive been in there to pull a few out and send back since. It still could be the injectors but from what im seeing its something else. I will also check the FICM again tomorrow hot and cold.

Thanks guys

Start with load testing the batteries, that's a good point. If one is bad, replace BOTH. That's the rule of thumb and could be your issue. Usually the older battery will drain down the new good one. Test those, then recheck the FICM.

Good luck with the batteries. If that's what was causing your problem at least it's an easy and pretty inexpensive fix.

My batteries were a little over 7 years old when they caused my problem. From my understanding that's quite a long time to make it in one of these trucks.

One had 780 CCA and the other only had 670 CCA going to replace both and see how she runs. What are some good batteries to throw in. I know optimas have went down the drain in the last few years and i am looking at Diehard Platinums but they are sure pricey. Anyone running anything they have had good luck with and didn't sell their first born for?

I'm going to most likely go with the duralast golds because of price and they have pretty good warranty.