this just started happening today on my way to work....driving to work and while coasting to a stop i noticed my car (1990 gxl) starts to backfire consistently until i push the clutch in. This is the first time I've noticed this occuring, it only used to backfire if I reved above 6000ish. Any suggestions on what may be causing the problem?

 

mine did the same. Make sure your TPS is adjusted.

 

is it a fairly easy process, i'm not overly mechanically inclined but don't mind learning. i'm assuming the entire process is in the fsm?

 

oh yeah. peice of cake. I made a test light myself with little parking lights. PM me if you want help with that. The info is in the FSM on how to adjust it. I would start there. Let me know how it goes.

 

sounds good, i'll hopefully try it tommorow, i just read the part in the fsm and it seems easy enough hopefully it's a nice easy fix

 

is it the same process for s4's as shown in this link http://fc3spro.com/TECH/HOWTO/TPS/tps.html or is there something else needed for s5's

 

Here's the link. How to adjust is on page 84.

http://www.teamfc3s.org/main/factory..._non_turbo.pdf

 

It's slightly different with S5s as you suspected - they have a different dual range TPS. Check the FSM link above or here for a how-to.