I have an 02 Excursion w/ a 7.3 and 4x4

I was driving the truck earlier this week after I left work I went to get a hair cut and left the truck to idle. I came out 15 min later hoped in and headed to the house. By this time it was up to operating temps. About 3 miles down the road I hit a stop sign and go to pull out on the highway. It was at this time that the truck had a massive loss in power and a very significant vibration. My initial thought was that the trans had just crapped the bed so I took it out of over drive, no change. Fortunately I was close to home and limped her back. I pull her into the garage and hop underneath, no fluids are pouring out, I look at the gauge on my trans and my pressure is good, the fluid is still bright red and not burnt. The idle was a little shaky but wasn't in danger of stalling so I gently rev the engine in park and the vibration (read: miss) is still very prevalent. So I have reasoned that it is the engine and most likely a few dead cylinders for lack of fuel is my problem?

I have no CEL or codes and yes the CEL does work. I have owned the truck for 50K and the previous owner was meticulous with maintenance and I have been nothing shy of OCD. With in the last week I have replaced the fuel filter, EBP sensor and cleaned the tube as well as the ICP sensor and pig tail, replaced the gaskets on the oil cooler, replaced the dipstick gasket and did two oil changes. and none of that was related, I had notices some leaks and wanted to nip them in the bud. The only thing that may have lead up to the event is I noticed a little bit of a stumbling idle for a week. But that very well may have been in my head.

Now thus far I have tested the valve cover harness and everything was with in specs and extremely close to each other. I was really hoping the 50 cent mod would be my cure but it doesn't appear to be the case.

I am a very handy guy and I do all my maintenance. But I am pretty new to the PSD and at a massive loss right now... I have done my best to give a very detailed explanation of what happened but I very well may have missed something and I would greatly appreciate some help.

 

After reading and participating in the other thread, and now seeing that you had some symptoms of misfire/stumbling leading up to this, I'm leaning toward the injectors themselves being the problem. There are a few things that would help narrow it down. It would be helpful if you had a way to log some data like ICP, IPR duty cycle, etc. For lack of that, I'd pull the valve covers and start the engine. Watch the oil discharge carefully from each injector spout and make note of any that seem to be spitting less oil than the majority. With the engine still running, disconnect the wiring to each injector solenoid one at a time and see if the misfire gets worse. If it does, the injector is at least working. If dropping a connector off makes no difference, the injector is suspect. One caveat I should mention is if you do this with a cold engine with thick oil, keep an eye on the oil level in the heads as you work. You may need to shut the engine off to let the oil drain back if it starts to overflow at the back corners and run onto the ground.

All of this assumes you've already checked the wiring for chafing, especially on the underside of the 42 pin engine wiring harness connector where it sits over the left valve cover. That is a known point of wear, and you'll have to pull it to get the valve cover off anyhow. It also couldn't hurt before you even get that far to pull the connector off the IDM (behind the driver fender liner) and test the resistance from there all the way to each injector. I posted a pinout here: https://www.ford-trucks.com/forums/1...l#post14172980 Check resistance from pins 23 and 24 to the corresponding injector pins shown in the pic. A persistent wiring problem would *normally* set a code, but verifying it with a meter costs nothing but a bit of your time.

Anyhow, let us know what you do, if you have any luck tracking down the problem, or have any problems or questions.

 

So is the bad running all the time now, or just some times? Got a knocking sound when it's low on power?

 

awesome thanks for the replies. Should I reconnect the intercooler piping after I remove the valve covers and prior to starting the engine? Also when I start the engine with the covers off should I expect quite a mess?

Honestly I would rather buy some type of used android device and down load one of the programs you mentioned in the other thread w/ the blue tooth obd connector and do some logging over pulling the covers and starting the truck to look for something thats wrong. I mean thats the point of having a truck w/ a ECU right?

It started missing 3 miles from the house, I couldn't (was afraid to) even try to drive over 50 mph when I got home I put her in the garage and thats where she has been for 4 or 5 days. Haven't even tried to start her since

 

You don't have to connect all the tubing. It will run without it. There are a couple of things you need to be sure you do.

One make sure there is nothing loose and small that can get sucked in to the turbo when it is running ie: plastic bags, paper, etc.

Two take a bungie and connect it to the underside of the hood and the 42pin connector.

Running with the covers off will not make a mess. Don't worry about it. As for the apps, it won't tell you if your injectors are bad. It can give you hints, but the only way to be sure is pull the valve covers and then go from there.

 

The PCM can't monitor the mechanical side of the injectors, only the electronic side. The electronic side of an injector consists of nothing more than a solenoid. A cylinder contribution test or watching individual cylinder rotational velocity may tell you something. However unless you have an OEM black camshaft position sensor, it tends to be inaccurate, especially with cylinders 3 and 8.

A more valuable test in this case would probably be the injector buzz test. It isn't conclusive, but it can give you an idea of where to start. The problem is unless you know the difference in sound between good and bad, it may not mean much to you. Car Gauge Pro will do both CCT and buzz tests, and can be set up to watch rotational velocity on each cylinder. The user interface is a navigational nightmare though, lol.

Starting the engine with the CAC tubes off is no problem. You do need to make sure there's nothing that can get sucked in to the turbocharger or manifold, though. It isn't messy running the engine with the valve covers off. The only oil is what comes out of the oil deflector spouts on the injectors. You will need a 13mm universal socket to get to some of the bolts, especially the ones next to the HVAC housing on the right side. It makes the rear bolt on each side easier too. The gaskets are reusable. It's not a particularly hard job, but it can be frustrating the first time. One thing I found makes it easier to get the right valve cover out is removing the bracket that holds the MAP sensor from the top of the HVAC box and keeping it out of the way.

Whichever way you decide to attack it, there are plenty of people here who can provide help and advice.

EDIT: Jason beat me. And he makes a good point on the bungee cord to keep the wiring harness off the rockers.

 

I would start it back up and see how it idles first. Your low power while trying to accelerate could be nothing more than a fuel restriction.

 

That' s quite possible too. I may have jumped to the wrong conclusion. And since you're in Alaska, how cold was it when this happened? Any chance your fuel could have started to gel?

 

What kind of fuel restriction? My fuel filter is literally 10 days old. I do live in Alaska, North Pole at that! But it was a beautiful day, about 30 maybe 32. Had all the windows down and a tee shirt on! Gelling should not be an issue at all as we're still on winter blend gas. I've started the truck down to -50 this year. Granted I left her plugged in all night but I've never had a single issue with drivability. Only heat!

I think I'm going to pull the valve covers tomorrow anyhow. I have most everything already pulled out of the way already. Won't be much more to pull the covers and see. Excuse my ignorance but which connector are you refering to with the bungy chord?

 

So ignore my question about the 42 pin connector, took me all of 20 seconds to figure that one out. I pulled the left valve cover, it was rather simple. The rear most bolt was a bit annoying but not bad at all. I am astounded of how clean everything is for having 290K miles. It all looks to be in order but I am no expert.





Now I did find one thing out of the ordinary, I don't think it is my problem but I do think it could quickly become a problem. The side of the 42 pin connector that has the bolt in it was sitting on the valve cover and 3 wires were a bit worn but didn't appear to be through the shielding



I am going to call it a night and drink some beer. I'll get to the right valve cover in the morning

 

Another question about the fuel. How much is in the tank? Do you have at least a quarter of a tank?

The inner valve cover gasket connector in the picture looks like it might have backed out a tiny bit, but I doubt it's enough to cause a problem. While you have the cover off, remove the connector from the socket and inspect the pins for any sign of heating/melting/burning then re-seat it.

 

Have you done the in tank mods? There are screens inside the mixing chamber in the tank that can become plugged up and cause a restriction under load. https://www.ford-trucks.com/forums/7...ml#post7497739

Here's a link on how to keep it from happening again. Welcome to guzzle's In-tank Hutch Mod Web Page

 

Currently just over 1/2 tank. I rarely let her go below a half a tank.

Ill probably knock out the 50 cent mod while I'm in their.


I will check out the links. I have never done any in tank mods.

 

Have you started it today? Any difference in the way it runs?

 

Alright I pulled the right valve cover and started the engine. All injectors seem to flow pretty evenly. The two rear most on the right side were difficult to see but they were flowing. On the right side furthest forward cylinder there seems to be a piece of casting missing? It is freaking me out. I also noticed on the right side that I seemed to have some exhaust coming out of the furthest forward cylinder. It seemed to be coming out of the holes for the push rods making my eyes water