Two weeks ago while pulling my trailer my ex started to misfire. Changed fuel filter. No change. Removed hydra chip. No change. Put some fuel conditioner. Ran truck for two weeks with no problem. I'm out of town with work of course. Wife was driving Ex started running rough and killed. Restarted ran a mile and killed. Drained some fuel from filter and made it home. Still running rough. Drained filter into glass jar with no signs of water. Son checked for codes. None were present. Truck has aftermarket air filter, walker btm, and hydra chip. Any suggesting?

 

With no codes stored. Check Fuel Pressure. Go from there.

 

Extremely low oil level (3-4 qts down) will mirror low fuel pressure symptoms. It's a cheap thing to check, and often sneaks up on you, especially if you live where roads get treated with salt and your oil pan leaks like mine used to!

 

Fuel level below 1/4? Below 1/2?

 

Oil level full. Fuel level 1/2 tank

 

Just as a simple test, try adding more fuel. If this solves it, the hardware in the tank may have an issue, like a foot fell off.

 

I have a 99 f250 7.3, mostly happens when I'm pulling at high rpms it will miss and spit out a little smoke. My truck does not smoke and is completely stock besides an intake. Idk why it's missing at high rpms but sometimes happens when I'm
not pulling

 

Also I want to add that I top my truck off everytime I get fuel, the miss happens throughout the entire tank. I fill up when it gets between 1/4-1/2. It has been run empty one time and I've heard that's bad maybe this has something to do with it?

 

Sounds like UVCH to me.... You can pull the valve covers and check the connectors do the .50 cent mod OR replace the harness and valve cover gasket with a new set.

 

I had a start, then it would start missing problem that mirrored some of your symptoms. I pulled the UVCH harness and while they were slightly loose, I don't think that was the problem. I then pulled the ICP sensor and there was oil in it. When I replaced the sensor all seems good again. The ICP sensor is a lot easier to check first before pulling valve covers. Ask me how I know or just look. Somebody has a picture here or just do a search for ICP picture.

 

I checked my ICP sensor and it has oil on it. Looked around. Dealer wants $250 for the little guy.. Smyth wants $150. You think this will clear up my miss?

 

Several other folks on this forum said can cause problems. Some suggest that you could try cleaning it with something like brake cleaner as a tempoary fix. I opted to just replace it. That fixed mine.

 

Finally got home to work on the Ex. Checked fuel pressure . Good at 57 psi. Checked fuel in bowl and filter ok. Disconnected hydra and miss was still there. Took to a friends shop and hooked to his lap top. Ran KOEO and KOER test. Found small problem with #8 injector. But nothing to cause killing and miss fire. Dropped tank and big screen was in pieces in bottom of tank. Screens were clogged with screen pieces and rust. Rust coming from vent pipe of filler next. Performed hutch method of pickup and installed external filter. Fuel pressure went up to 60 psi. Running good so far.

 

I'm glad someone is having some luck!!! I've ordered the icp just waiting to see if this fixes the problem. I've wiped it clean and it's definitely toned down the miss. I think this will clear my problem. Mine doesn't die so hopefully my tank is in good shape.

 

It can be frustrating trying to nail this type of problem down as there are a number of different things that can cause the similar symptoms. Maybe we should just take them to the dealer and have them put their super duper diagnostics on them and they will have it fixed lickity split. Of course that would be cheap too.

Mine was the ICP, but it can be so many other things.

I'm just glad for all the folks here that are ready to help us work through stuff and get our trucks running right again.