5th gear dogish

[i94ponycar]

My '94 GT Vert is stumbling in 5th and ONLY 5th. It accelerates better at say 1/4 throttle than it does any more pedal than that. 4th and down there is no problem whatsoever. Any ideas??

 

[CC'S95GT]

how old are the tune up parts?
clean MAF and IAC, air filter, fuel filter.
Have you pulled codes? you can have a code without the CEL being on. follow the procedure in the haynes/chilton manual. Do a KOEO AND KOER test.

 

[MustangChris]

CC is pretty spot on for some of the issues you're having.

 

[mcglsr2]

What speeds is this happening? Highway speeds? 45 MPH?

 

[i94ponycar]

i'm replacing plugs, wires, rotor yada yada yada this week hopefully. It happens in 5th over say 50mph. I'm not driving right now though i'm posting

 

[330CubeGt]

Fith is dogish to begin with. Odds are its a tune up issue. Or bad gas could cause it to ping with a lot of gas and a low rpm load. Keep it in 4th unless your doing 60+

 

[RichV]

I agree with everyone else codes, do all the tune up stuff, check and make sure your firing order is correct, adjust timing to 10*.

I bet you'll find something wrong. Years back I had a 79 that had a funky stumble, you could only feel it at highway speeds. Turned out someone had put the firing order to HO, which this one was not. When I figured it out, not only did she run a lot better, but it felt like I gained a 100HP.