My 95 Jimmy has a very rough idle and is running very rich. The check engine light is flashing (obdII) and it used to just stay on all the time. The code is a knock sensor so I have replaced that. I havent had time to really look into the problem but any ideas would be great. Thanks in advance.

 

Misfire & running rich are likely tied to an FPR failure which would dump fuel inside the intake manifold. Check your fuel pressure. It should be >55psi and not drop more than a few psi after the pump shuts off.

 

And may I ask where the FPR is located on my Jimmy? Never had to mess with one on either one of my Jimmys

 

Fuel pressure regulator on Blazer 4.3L CPI W engine

The search feature is your friend.

 

Thanks a lot for a heads up to the link SWARTLKK.. And to the search feature that of course I knew about but was to lazy to use! haha.. I dont come around much anymore too busy with school. But this sounds like my problem cause its been running rich and getting worse and worse gas mileage over the past few months.. Granted I bought this particular Jimmy around June/July with 184K and now it has almost 192K. Guess Im tearing the intake apart this weekend.. Thankfully I have no class on fridays!