460 engine stumbling under load
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More Turbo
Joined: Jan 2013
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I'm going to keep driving it until something more bad happens than some light stumbling. I have a digital temperature gauge installed in the test port and temps are low. 150s in winter, 170s in summer. Unit only has 89,000 miles on it.
I can't really tackle this job in my driveway and be sure I get it done in 24 hours and it would probably cost $1000 to have my mechanic do it.
Steve
I can't really tackle this job in my driveway and be sure I get it done in 24 hours and it would probably cost $1000 to have my mechanic do it.
Steve
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Joined: Oct 2014
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My 88 E150 with a 5.0 and AOD transmission has almost the same symptoms that yours is exhibiting. Between what you an and I have changed out on our vans.electronically, The ECM is all that is left on my van.
IF I am correct, the AOD uses a non locking converter and the EAOD does?
I changed my O2 sensor about 15k miles ago.. After my van is warmed up and I cut it off for 15 or more minutes, most of the time the engine will surge up and down for less then a minute and then straighten out. My thoughts are 1- leaking injector. 2- bad O2. 3- bad ECM... What does that have to do with stumble at higher speeds under a load? I think the ECM is probably not processing the info correctly. 139k on my van but the ECM is 33 years old.
I guess I am getting back to the only part you have not changed,,, your ECM...
IF I am correct, the AOD uses a non locking converter and the EAOD does?
I changed my O2 sensor about 15k miles ago.. After my van is warmed up and I cut it off for 15 or more minutes, most of the time the engine will surge up and down for less then a minute and then straighten out. My thoughts are 1- leaking injector. 2- bad O2. 3- bad ECM... What does that have to do with stumble at higher speeds under a load? I think the ECM is probably not processing the info correctly. 139k on my van but the ECM is 33 years old.
I guess I am getting back to the only part you have not changed,,, your ECM...
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More Turbo
Joined: Jan 2013
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I've been gong back through my old posts to research fuel pressure regulator part numbers, as my FPR has failed, I am nearly certain.
Just wanted to update this thread to say, the stumbling issue was due to a broken in-tank fuel pump. This causes vapor lock when the high pressure pump sucks hot fuel from the tank through the dead pump and upstream. Flashes the fuel into vapor when it gets hot. This causes stumbling and eventually a no-fuel situation, until it cools off, then runs fine, and repeat.
Just wanted to update this thread to say, the stumbling issue was due to a broken in-tank fuel pump. This causes vapor lock when the high pressure pump sucks hot fuel from the tank through the dead pump and upstream. Flashes the fuel into vapor when it gets hot. This causes stumbling and eventually a no-fuel situation, until it cools off, then runs fine, and repeat.
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