2.3L ('83-'97) Engine "stumbles" intermittently NEED HELP!

[jcwhidby]

1997 Ranger XLT 2.3L Manual Transmission. The engine on my ranger stumbles intermittently at idle and while driving. The engine stumbles and almost immediately recovers, it occasionally dies if it occurs at idle but usually recovers very quickly. While driving it acts like the engine has been shut off with the key but in a fraction of a second it comes right back. The engine runs very smoothly at all other times. Sometimes this will happen every few minutes and other times it will run great for 500 miles between issues. The only codes currently in are P1443 Evaporative Emission Control System Control Valve and P0401, EGR Flow Insufficient. I don't know if either of these could be related to the stumbling problem. Several mechanics have looked at the issue and don't know what is wrong or where to start. Any ideas or suggestions would be much appreciated.

 

[digitalbayou]

You have a leak in a vacuum line. This will alleviate this stuttering at idle. I have a lean bank code and egr code that I am diagnosing. I was told that I need to change the fuel filter but I did after doing a fuel treatment. I am under the impression that I will replace the fuel pump because I am under the impression that it has worn out. Dunno until I check it because I have no fuel pressure gauge. Cheerz.