Poor acceleration at 50-70mph

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Dec 22, 2012 | 05:05 AM

Keepitrunnin

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Poor acceleration at 50-70mph

2001, F250, 5.4, 4X4. Getting on the highway, truck doesn't want to get to speed. Vibrates and downshifts. After about 70, it smooths ouit and runs ? Thanks.ine. Any ideas on where to start

Dec 23, 2012 | 09:48 AM

Furian

You Keep What You Kill

Joined: Dec 2006

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From: Huntersville, NC

Have you checked your transmission fluid? When was it last serviced?

Dec 23, 2012 | 04:21 PM

Keepitrunnin

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Tranny is due for a change, but the fluid level is good and no burnt smell. It's clean. This started after filling up at a station I don't normally use. It was about 3 tanks ago. I've added some stuff to the gas and injector cleraner, but still the same. I'm going to change the fuel filter next. At slow acceleration, it's OK. After running at 70+, it smooths out and runs fine. It idles fine, so I'm at a bit of a loss.

Dec 23, 2012 | 07:11 PM

Bigpipes 35

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From: Forest lake minnesota

If it seems like it loses power with with higher rpm like if you step on the gas and it down shifts and it seems like you lose speed or power instead of gain I would check the catalytic converter. Thats what was wrong with mine..

Dec 23, 2012 | 07:19 PM

Keepitrunnin

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Thgose are the symptoms. As I get on the highway, I step on the gas, it downshifts, but doesn't accerate quickly. Than slooowly, gets up to speed. I'll look into the converter. Thanks.