2001 excursion limited 7.3l

Out towing through the mountains and it was going good (3rd gear, 14is psi, hualing nice) and then it hit like a wall. It would be in 2nd gear floored, 3k rpm, like 2 to 4 psi of boost (highly suspect), about 2300psi hpop, about 40 to 50 mfdes (due to low boost). This wasnt the first big hill and it was fine. Temps good. Felt real gutless like i wouldnt make it up the hill(but it did). I was towing a 8k tt though the mountains. Not smoking or anything and seems fine once i get out of the throttle (level ground). The engine has extra shakey and hesitant. No obvious fuel leaks, however i dont have the means to check fuel pressure. I could get around 10 psi and then once i hit grades it boost would plumet.

I have limited tools and diagnostic stuff (got forscan though). These are the codes pre reset. Wont be driving much more today but definitely seems like a boost leak. Ill drive it tomorrow to see if the boost codes come back.

The low voltage will be left overs from a few weeks ago. Voltage was good for the trip.




This is what comes back after reset (basicly nothing).



Seems like a blown cac boot, so ill dig around, but any other ideas might be helpful. Nothing looks out of place. Truck is basically stock. Maybe its the couplings at the spider? Very low amount of turbo noise/whistle then usual.

EDIT: the truck still made it to the destination and i don't leave till Saturday. So i am safe and not on the side of the road or anything

 

I’d suggest filling out your sig and add whether or not your excursion has the hutch mod or bellowed upipes.
I assume you checked all boots, fittings and the map line. I look for spots that boost has blown oil off. Of course a disconnected map line kills boost. You could probably put together a gauge and some hose with clamps to check fuel pressure. Ssj had a write up about connecting to the drain pipe on the back of the fuel bowl. Reduces the fittings needed to make the connection, just 5/16 hose and a clamp.
With forscan you can check ebp to map at Koeo. Should be within 1psi of ea other. If there’s a big difference this can affect fueling.

The guys will be along and suggest logging some runs in forscan.

 

I’m wondering if you have a fuel issue. You said temps were fine (EGT too I assume). This leads me towards lack of fuel. If you were not making boost but still had normal fueling, I would expect the EGT to go up quickly. Just my wild guess.

There’s a method to check the fuel pressure at the bowl drain in the tech folder. Here’s a link to it. https://www.ford-trucks.com/forums/a...4&d=1592859516

 

Hey.

I have bellowed uppies (done 4 years ago). No egt gauge or tuner. My guess is egts were high when it was in second gear planted. Babied it more from there. Stock air box, stock engine, stock turbo. No 7 turn mod even. I am coil swaped though. Even still have the red tube (shes really stock). Deleted the ebpv. Oil up to level but near oci. T6 5w40. Coolant looks fine, and at the normal level it stays at. New water pump and resivior last summer. Gauge stayed in its place the whole trip and fan only came on when pulling with low boost. Oil was around 100*c but i run a warmer thermostat and we were loaded. Peak oil temp for the trip was 107*c...pretty typical for my truck loaded. Hutch mod is basicly done (i have a second tank and aftermarket pickups with filters, no factory fuel fittings on sucking side). No leaks that i can see. No raw fuel smell (know this smell very well, truck has had lots of leaks) My factory fuel gauge did work but stopped again a couple months ago and should have lots of fuel (filled the tank anyway) . Fuel pump is about 4 years old. I dont suspect fuel because the truck wasnt requesting a ton of fuel (it was like flicking a switch, cruising ok, then switch, sudden loss of power, low boost, low mfdes, no cel, transmission down shifts and unlocks tc and truck feels like she might not make it). We were doing the Honda chug lol. Also switched tanks and no difference. Second tanks gauge works and no noticeable difference in power (it also had lots of fuel). Second tank is the aftermarket one. Its the one i use most of the time (24gal), and leave the stock excursion tank near empty unless i need the extra fuel (say to haul the tt through the mountains). Like to keep up on fuel blends as our climate is wild and i have had to tango with gelled fuel a couple times (though i have a cheat code for that).

Ill take it all the cac stuff apart tomorrow and maybe get the hair spray out. No air compressor or real mechanical place near me, and no Amazon (i have all this at home, which is 4 hours away). The small town is isolated, so parts are probably thin for a 25 year old truck. No obvious boost leak and I wont have access to a good parts store so its going to be a duct tape sorta fix to get her home (with the tt).

Nothing weird with the transmission other than it was trying to keep the truck moving. Tc unlocked in second and a decently high tcslip when issue happened. Temps were 65*c so well within normal. It wasnt an overly warm day. No funny stuff at all.

Ill update with the cac stuff, and filter status tomorrow. If it is bad fuel, the second tank is very easy to drain. Maybe a bunch of water? For now, its miller time.

Sorry for all the words.

 

Glass container or clear plastic bottle will work. Open bowl drain and catch it in a bottle to check fuel quality.

 

I’m sorry, when I referred to fuel I meant fuel pressure/volume or introduced air not quality. But my logic behind the thought is moot since there’s no EGT gauge.

It would be nice if you could find enough parts to do a fuel pressure test and boost pressure test before the trip home.

Also look at the wastegate to make sure it hasn’t become disconnected at the rod.

 

Ill check the waste gate. Thats a good one.

I do have to run into town, so ill see if i can recreate the issue and data log it. See if the low boost codes come back. I was fooling around a bit rolling into our destination and there was very little turbo noise...which is highly suspect. Ill see what i can find for a fuel pressure gauge, but i dont know if that will be a success. There is a hub town 1.5hours away, but lets see what the cac piping reveals. I did check yesterday and nothing seemed out of place, and the intercooler pipes seem tight, so its probably the plemums or spider connections. No hole from the power steering. I didn't check the red tub stuff, but ill get some stuff to do the red tube mod, just to rule that out.

Also with a peak mfdes of 74 for the trip, which actually seems a tad low flat out, im thinking a boost leak may have been working itself worse and worse and the trailer was the cherry on top for whatever is loose. With 30 to 40 mfdes at 3k rpm in second gear and low boost (and i was pulling up the hill just fine for 3/4s of it, and there were plenty of hills piror to this one), make me think the truck wasnt trying to go anywhere near flatout. Also there was no notiable black smoke. Without a tuner, it bearly smokes ever. You get a bit of a black haze flat out, but no coal rolling here. Big reason for getting a tuner is to help with the shift point towing, and to maybe get more jam at the 1800rpm range. I also want the new gen 3 kc turbo as the dyno graphs suggest very good boost in the 1800rpm range.

Ebp seems ok. I am seeing a couple psi more at higher throttles. I have a suspicion that my factory muffler is rusted and or plugging up. It does eem to be reading ok though.

Ill report my findings after taking the cac pipes and spyder off. Ill aos take note how it starts. A fuel issue could impact starting (a longer crank).

 

New thought. Do you read boost through the MAP sensor? If so, maybe is holding back fuel due to the MAP seeing low boost numbers. I think someone mentioned the MAP hose. Seems worth looking into if you haven’t already.

 

Ok, so i decided to tear into the cac piping and nothing looks out of place. Maf pipe is good as i had hose clamps on that. No tears or rips in the boots that i can see. Red tube piping was barely attached. I have deleted it for now.

Waste gate is attached but it appears the shaft/rod on the turbo is rubbing the rear coolant pipe. Could it get jammed open?



Note the gouge on the black coolant pipe.


Im going to put it back together and clean everything well. See if i can dig up some hair spray.

Then ill fire it up and check fuel pressure. I did find a gauge. Wont be able to use it i dont think while driving, but might have a hint for another issue. The parts store does have a fuel pump and fuel filter if required.

EDIT: the map hose is cracking at the end. May just preemptively replace it

​

 

That wastegate contact looks to be promising as the source of your issue. Fingers crossed!

 

Good news. 18 psi and holding. Unloaded though but that is a nice number. No stumbling and pulled well.

Some new issues to look into. That wstegate rubbing is a concern, and i may have some new minor fuel leaks (blasted fuel bowl and maybe at that clamp on the fuel line by the turbo).

Im going to call it good enough to get home. If i had to guess, the map hose and red tube stuff was leaking. Maybe on of the clamps wasnt holding too good or something too for a boot.

Miller time for a job well done....for now. Thanks for the replies and help.

 

Good job getting it sorted for the ride home!

You earned 2 Millers in my book.

 

I'm late to the game here, but the first post sounds very much like an overboost, then defuel event to me. Especially if an engine restart cleared everything up. (Didn't see if that was done or not).

 

Got home safely. 20 psi of peak boost. There was lots of wind but no noticeable power dips. Pulled pretty good.


Ill pull it into the garage probably next weekend and deal with the fuel leaks and wastegate.

Thanks again for the help.