Engine losing power around 4k
 

So my buddy has a '98 Dakota, and just today started having the following issue. When you rev the engine, and it passes around 4k or so, there is a noticeable drop in power and the engine just stalls around that range for the remainder of gas pedal travel. Sounds sort of like it's bogging down for the last 3rd of accelerator.

Any preliminary diagnosis? I told him I was leaning towards a fuel pressure issue such as the fuel pump? Idk...

Thanks for any help.

I agree with a fuel pressure issue. Do you have access to a pressure gauge to test the system?

No, but I imagine you can borrow one from the local auto parts store.

I failed to mention that he has had some issue with the catalytic converter rattling, and currently has a new one that he's gonna get welded in. So he could have an exhaust leak, however I don't know if it would cause that drastic of a power loss around a certain rpm.

There is also a clicking sound under load, so that could be either exhaust or the lifters. But again, I don't know that that would be the main power loss issue either.

get that cat changed out and see if the problem persists.

if so, then check fuel pressure and ohm test the injectors.