Hey guys. I feel like a sophomore at Diesel State University. I'm learning a lot and I'm almost there. After AE said #8 was fritzed, I went in expecting bad O-rings. What I found was an AB injector in an AD engine. I put in a used long lead (posted about it a while back), and that helped. "correcting" a stopped up cat also helped, as did a new CPS when it started stalling. Another new fuel filter also made things better last weekend. When it gets moving with a little throttle, it smooths out and runs pretty well. 4-6 pounds of boost at highway speed. AE says the ICP is running around 1800-2000 20-30% DC. That looks ok. when it returns to idle, many times it undershoots idle RPM and recovers. Occasionally it returns cleanly. My big gripe is that it still has a miss, not a dead miss, but noticeable at idle, and it smokes dark at idle. Not dense enough for me to say it's black, but dark, and clearly smells of fuel. It clears as the miss clears with about 10-15% throttle (sorry, I haven't monitored throttle position with AE- just estimating). AE also continues to say #8. Any thoughts on what kind of failure mode I might have on that injector, or anywhere else for that matter? I really love this truck. I think the only thing I would love more is to get to the bottom of it so I can simply drive it for a while. Thanks again for the input and the awesome forum!

 

Tuner?

Last link in my signature might have some info.

 

Not that I know of. No switches. The truck was a fleeter with an oil field company out of Texas, then it just passed through a few dealers before I got it. I doubt they chipped it. suppose I could check, but don't really know what to look for.

 

Tuner not likely. With smoke at idle, I'd wonder about the condition of the intake filter. Other than that, there are a lot of variables... like a bad nozzle on an injector, a bad sensor, compression, etc.... Turn the oil filler cap upside-down on the fill spout. Pops up, or hovers there?

 

Went out just now and flipped the cap. It didn't go flying, but it didn't sit still, either. I know where that's going, and I dislike it. The thing doesn't seem to use much oil, and it stays fairly clear. I would think if the comp was low enough to idle bad it wouldn't smooth out at power. New air filter couple thousand miles back and almost all city/highway driving.

 

Sorry for the delay... your last post shows undue worry. The oil cap will hover or slide off. You just don't want pop-ups. I'm not the expert, but blowby is by no means subtle with the oil cap.

Have you had a chance to go through that first link in my signature?

 

No need for apologies, Tug! I had actually seen that document before, it is very helpful. It is puffing rather, just not violently. My limited experience suggests that if the bore wall is scored up, it should be using quite a bit of oil and smoking more white. How common are broken rings? If I'm led that direction, has anybody ever re-ringed one in the chassis?

 

That is waaaay outside of my expertise and comfort level. Broken engine to me means a big bill and time in the truck hospital.

 

The local Ford dealer is our airport manager. He just popped in for a visit. His advice was "Trade it!" My reply was NO! I have every confidence that an aircraft mechanic and an army of experienced Powerstroke experts can and will eventually make this damned engine idle right!

 

If you have the gray CPS #8 will always fail the CCT. In some trucks #3 & #8 fail CCT with gray CPS.

This is a known problem and Ford issued this Special Service Message about the gray CPS and phantom CCT codes.

Nolan (4inchlovin) posted this a few years ago.

 

Thanks, Robin. I just put a CPS in it less than 1000 miles back, but it IS grey (when it stalls in the middle of the main drag, not even FedEx can get it there fast enough- Auto zone has to do.). I've heard of the CPS trowing #8 CCT codes. Could this also account for the partial miss at idle, and which sensor do I want?

 

When I was running a grey CPS #8 would always fail and #3 would fail intermittently, but I didn't have a miss at idle. If you only have a miss at idle and not off idle it could be the grey CPS. The DU-87 CPS for the 94-97 7.3 works fine in the 99-03 7.3. When I had a DU-87 CCT passed all cylinders, but I lent one to a friend and his still failed #8. I haven't retried a DU-87 since installing an original black CPS.



The original black CPS is the best but have been manufacture discontinued and are all but impossible to find. The last one I saw for sale a few months ago the seller wanted $165.00.

 

Yeah, Robin, it gets down the road fine (except when the fuel filter stops up), just smokes and misses at idle. Again, not a dead miss, but there. What is this stuff I hear about a new "dark blue" CPS, and what of the versions for the T444E?

 

The T444e and the 7.3 are them same and as far as I know use the same CPSs. The dark blue CPS is the DU-87.

See this LINK for Ken's (woodnthings) CPS test comparison.

 

Thanks, Robin. I'll go see our local airport manager/ local Ford dealer and see if he's got the new one. Any thoughts on why it's undershooting rpm on return to idle? Seems a weird one.