94 3slo at 4x4 in the past month or so ive noticed that right at 35mph on the speedo there is a very suttle drop in power during exceleration. no matter what size tire im running. no cel speed sensor? not sure where to begin. any ideas?

 

Fuel delivery?
1) filter- when was it last changed?
2) pump- how old is it? What brand?
3) pressure regulator- probably not it, but it's a possibility if others are ruled out.

Just a few places to start. How does it idle?

 

Pull codes first.

 

filter less than 6 months fuel pump 4 years idles perfect at 950 in drive 1050 or so in park but smooth ill check codes again tonight, 3 years ago i got a code something about no speed signal or something cant remember for sure

 

Does it matter what gear you're in?