nicejeep
10-04-2002, 11:30 AM
My 97 auto 4.0 has the check engine light on. Here's the story: While driving on the highway, it shuddered really hard, then went back to normal. When I got to a stop sign I noticed it was misfiring bad. The next morning, my check engine light came on. I changed the plugs, wires, cap & rotor, cleaned the air filter. Did a pressure test on the fuel rail and got 49 lbs. Did a smoke pressure test on the intake and I do have a small leak around the throttle body, so I need to replace the gasket. Put injector cleaner in two tankfulls now. All my vacuume lines have good suction and seem to be fine. All my sensor wires are plugged in tight. Put a code scanner on it and came up with codes for random multiple misfire, misfire on 1 & 5, and a code u-1400. Does anyone know what that is? Can't find anything about u-1400 on the web, or in any of the manuals. Since I have done the other stuff, it does run better, but the light is still on and I can hear a misfire at idle. Once you get on the gas, it runs fine with plenty of power. The only other thing it could be is the fact that I put 5 gal of 92 octane in it about 3 hours before it shuddered. Couldn't make it to a gas station, so I used my 4-wheeler gas from a can. I'm stumped, please help!!