1)I have a 94 GS-R and sometimes while I'm driving at constant speeds it will stutter for a second or 2 then it will be fine again. I changed my fuel filter and it still does it once in a while. Could it be the injectors or maybe the fuel pump??

2) If it might be the fuel pump, I would like to get an aftermarket pump. My plan is to go turbo in the next year. What would a good pump be to get if I'm not gonna run over 11 psi??

3)Would the stock pump be adequate with a hondata. or does it still need to be upgraded when going turbo?

Thanks a ton guys. I think this is the only forum where you can actually get specific answers to questions like this

 

FWIW, my '90 Civic Si exhibited the following symptoms.

At a steady cruise in 3rd gear at 25-30mph, it would buck or surge slightly. Trying to hold a steady throttle pressure to maintain 2700rpm in neutral, the rpms would fluctuate by roughly 50rpm. My O2 sensor was slow and lazy. Replacement with an OEM Honda sensor cured all that. The generic Bosch sensors I tried (yes, two of them) didn't work well.

 

It could be an O2 sensor problem but it sounds more like an ignition problem. First, I would check the wires at the igniter- pull them off and pinch them with pliers to tighten, then reinstall. Also check your cap and rotor while you are in there- If there is a bunch of red dust- then most likely your distributor bearing is going out and not rotating smoothly. Try running some techron concentrate through your tank to clean your injectors. If you have aftermarket plugs- be sure the shitty top terminals aren't coming loose. Spary some water on your wires and distributor while it's running to check for worn/damaged cap and wires. Also, check your grounds.

 

1)on the cap and rotor. when I take off the cap , is that going to mess up my timing?
2)when I spray water on the system if the engine starts to run funny, that means that piece has a bad seal or crack. correct?

 

 

1-no
2- yes- you may see sparking- usually at the cap or along cheap aftermarket or worn out wires