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Posted By: Psylock1045 Replaced alternator now van won't stay on? - December 23rd 2020 5:08 am
So I just replaced my alternator. Was having all the symptoms of a bad alternator. Battery not charging, low power in lights, needing a jump start, etc.

Replaced the bad alternator with a remanned one, and the power works great now.

The problem is, now the van won't stay on!

It starts right up and roars to life, then just.....stops. If I gas it hard I can keep it running, but if I let up it still dies.

Any ideas? 2002 Ford E150 4.6L engine
Posted By: NateB Re: Replaced alternator now van won't stay on? - December 23rd 2020 12:06 pm
Does it stay running if you keep your foot on the accelerator?
Posted By: Psylock1045 Re: Replaced alternator now van won't stay on? - December 23rd 2020 2:25 pm
Yes
Posted By: frscke1 Re: Replaced alternator now van won't stay on? - December 23rd 2020 4:36 pm
Clogged fuel filter or crimped fuel line ... could be the fuel basket in the tank...
Posted By: Lee7673 Re: Replaced alternator now van won't stay on? - December 23rd 2020 10:11 pm
Fuel issue. Like Frscke1 said could be basket in tank. Also check the fuel filter
Posted By: nikothenomad Re: Replaced alternator now van won't stay on? - December 24th 2020 3:19 pm
Are you sure you didn't knock any hoses off or brake any lines that would create a vacuum leak when installing the alternator? Have you done a vacuum check?

Does your van have an idle air control valve?
Posted By: Psylock1045 Re: Replaced alternator now van won't stay on? - December 24th 2020 7:08 pm
So I just fiddled with it some more. The alternator pulley is burning hot and i smell burning rubber, amd the van still dies after i let off the gas pedal
Posted By: frscke1 Re: Replaced alternator now van won't stay on? - December 24th 2020 7:25 pm
the alt pulley is not aligned right ...
Posted By: wrcsixeight Re: Replaced alternator now van won't stay on? - December 24th 2020 9:21 pm
Reman'd alternators have gotten progressively worse and worse, while their marketing saying how great they are has goten more and more generous to themselves.

Lifetime warranty means one gets to spend a lifetime replacing them over and over until they get one that was actually rebuilt by somebody not completely inept.

They ONLY replace that which was obviously failed, like perhaps one of the two bearings, and put it in a new shiny box.

If a Diode or 2 has failed, it will let alternating current into the DC wiring, and all sorts of weird crap can happen. and yes it can do this and still make 2/3 of its rated output, which can be more than enough to maintain expected voltages when the battery is fully charged and loads are only headlights.

A super hot pulley is an obvious sign that either the pulleys are badly misaligned, or perhaps a 3/8" belt is bottoming out in a 1/2 inch pulley, or the front bearing was bad and not replaced.

I bought a New nippondenso clone alternator from Autozone. Made in Malasia. rated 50 amps idle 120 amps max. When hot it is abuot 32 amps max at idle and can't produce more than 109 amps, so even the new ones are not built as good as OEM quality, but can be more than good enough, especially if one does not have the ability or desire to measure its output at different rpm with loads capable of fully fielding the rotor.

Here is a long involved article about mounting and aligning alternators. I recently found my stock original alternator location had the pulley 6mm out of parallel alignment.

Now I have that AND the ND alternator within 0.5mm.

https://marinehowto.com/marine-alternator-installation-tips-tricks/

Using the info in that link, and a good straight edge i also found my power steering pulley well out of parallel alignment. V belts do seem remarkably tolerant of misalignment, and Ignorance of the rather profound misalignment on my 318, was certainly blissful, But I am happy to have all the pulleys much better aligned, and I am sure my belts and pulleys are much happier too now.
Posted By: NateB Re: Replaced alternator now van won't stay on? - December 29th 2020 4:43 pm
May be dealing with two different issues here. That fact that it stays running with your foot on the accelerator could indicate a problem with the IAC (Idle Air Control) motor not allow enough air into the engine at idle. These can be removed and cleaned as well as the passages in the throttle body. The throttle plates are probably carboned up as well and should be cleaned. Some CRC Throttle Body Cleaner, pipe cleaners, and old tooth brush work wonders.
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