99 losing power in 4th

[Vulcanoven]

Have a 99 4 cyl. that loses power in 4th then gets up to speed slowly and can change to 5th only if maintaining speed. Have just started diagnosis. Air filter clear. That's all I have so far. Need a place to start. Has over 230000 miles. Any help appreciated!

 

[Jeff0266]

I think my first stop would be an auto parts place and see what codes is showing up. That would be a great place to start. I'm thinking it could be a number of things,from a basic tune up to maybe a clogged injector? I'm no mechanic but have worked on a few.

 

[DeanMk]

Have a 99 4 cyl. that loses power in 4th then gets up to speed slowly and can change to 5th only if maintaining speed. Have just started diagnosis. Air filter clear. That's all I have so far. Need a place to start. Has over 230000 miles. Any help appreciated!

...when's the last time the truck got a tune-up?...and don't forget fuel and oil filters.
Always start with the easiest remedy and work from there, so you've blown out the air filter with air, now onto the next easiest thing.