excursion power loss on hill

[jsmall]

Hey guys, I've been searching the net looking for an answer with no luck. You seem to have some real good guys here, so here goes. I took the Excursion(my wife's daily driver) to the lake yesterday to launch a buddys boat(its a 14' aluminum - very light). When I went to pull him up the launch ramp, the engine stalls out like I'm out of fuel. It doesn't die completely, just falls on its face then catches back up again. I had to go in 4Lo and just a hair above idle to pull it out. Any more throttle and it dies out again, After this, the OD off light began blinking. Light went off after a shutdown and restart. The Exc had gobs of power all the way home, but when I went to park the boat, it wanted to die again. I was backing it up a short hill into his garage. I can't have this thing leaving my wife and boy on the road somewhere, and am scared of the local dealerships.

[mschn99]

sounds to me like a possible tranny issue. First order of buisness would be to check the tranny level and condition.....

The reason i suspect this is the trans will bogg the motor down if its not functioning properly, and trans codes are what cause the OD button to flash...

[jsmall]

Exc has 102k on it. Tranny fluid was flushed as part of regular maintenance at 90k (when I bought it). Fluid level is right on, and fluid is clean and smells good.
The motor doesn't sound bogged down, it really sounds like it stalls, and catches itself just before it completely dies. When it happens, if I stay on the pedal, the engine hops back up to idle, then dies, hops back up, then dies...
I wouldn't guess it to be a load issue as the boat is very light, and it actually happened 2 times before with no boat, one time I was backing up a hill to hitch up to a flat trailer, the other time the wife was driving around a building site and was climbing a fairly steep little hill. On level ground, I can smash the pedal to the floor and I have gobs of power and the beast hauls the mail, nothing unusual (at startup or at highway speed), and I just pulled a stock trailer of cattle to the auction barn about 1hr 15min from here with no trouble at all. I even stomped on it just to see what she had, no troubles. (1st 2 times it happened was before this)
The only time it ever happens is on hills and it has happened both ways, backing up the hill and driving up the hill. The very first time it happened, was at the building site and my wife was driving and I thought she was doing it (like pumping the pedal or something). The first time it happened to me was backing up to the flat trailer, it was low on fuel and I was sure it was sputtering on its last drop. I shut it down, walked home and got more fuel for it. The last 2 times it happened I had 3/4 tank or more.
Sorry to go on forever, but I write in hopes that it helps diagnose.
Thanks for listening.

[jsmall]

Changed fuel filter. On the boat ramp, engine now acts normal, but OD off light starts blinking, same as before. The blinking ODoff light quits blinking after 10 seconds of normal driving. Is there anywhere other than a Ford dealer that can read codes?
thanks, john

[jsmall]

Pulled trailer over the weekend, the excursion still has the hiccups on small hills, and now it does it in reverse under load too (backing the empty trailer up over a 6" ledge into the barn).
Ok, I bought a code reader from Harbor Freight (under the condition that they would take it back if it was crap). Hooked it up and it says, 1 code.
P0720 Generic Output Speed Sensor Circuit Malfunction.
I just dont know what to do with that.
The OD off light wasn't blinking at this time. I tried to scan the codes with the beast running, and it shut the engine off.

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Last edited by jsmall : 11-06-2006 at 06:02 PM.

[~CrazyDiesel~]

CLimb up under the truck, and crawl over to the diff.

There is a connector and wires on the left top side of the diff.

That is the speed sensor. Before you try to buy a sensor, take the connector off, and spray contact cleaner in the connector, and the sensor plug.

This would fix the flashing od light, and possibly the other issue.

Is this a 7.3 or a 6.0?

[jsmall]

Its a 2000 excursion with the 7.3.
While looking at this, I found that the clips on this connector are broken. one is broken off, the other is cracked, but the connector was still plugged in all the way. I assume that it is a bit loose and this may be causing some of the issues. Can I replace the connector? Or should I just zip tie it together?
Thanks

[Logan]

Did that take care of your problems, if it did, I would just say zip tie it so it is not bouncing around. If it did not fix it, you might want to try something else or maybe one of the tech will see this. Good Luck and sorry to hear about your ex.

[jsmall]

Thanks Logan, I didnt have any cleaner, so I'll pick some up on the way home today and try this tonight. I'll let you know what happens.

[jsmall]

Replaced OSS (on the transmission), $25 from dealer, seems to have cured the hiccups. Thanks for the input Logan and Crazy.