This erratic idle will be the end of ...

Log Out | Topics | Search Moderators | Register | Edit Profile

Thread Last Poster Posts Pages Last Post   Closed: New threads not accepted on this page

Author Message   Joseph E. Pineda (Jedpineda) Posted on Sunday, December 29, 2002 - 10:07 pm:    Merry Christmas & Happy New Year to all fellow Rover lovers. Ok, here is a good one for you guys to figure out. 1998 Disco I, 74,000 miles. Problem: Erratic Idle at Park, at 70 mph idle lurches up and down. When cold, rpm at 2000! Things fixed: (Note: this Disco is religiously maintained). Intake Manifold gasket and end seals replaced new, no more leaks whatsoever. Stepper Motor (Idle Air Bypass Valve) replaced new. New spark plugs. New spark plug wires. New K&N air filter. New fuel filter. Cooling system flushed. Throttle body cleaned inside - its spotless. Throttle body coolant gasket replaced. All injectors tested and working. All hoses and belts are new. AFM tested and swapped with another same disco. HERE IS THE KICKER - NO FAULT CODES ON THE COMPUTER - CHECK ENGINE LIGHT IN NOT ON EITHER! When I disconnect the TPS (throttle position sensor) it idles fine, still a little needle movement, but the idle is livable. When I plug the TPS back, the idle goes crazy again. I really don't like driving it with anything unplugged. I've already ordered a new TPS, will arrive tomorrow. But something tells me that when I install the new TPS, the idle will still be erratic. I did notice some black residue on coil #5 where it makes contact with the other end of the plug wire, the rest of the coil pack is clean and shiny inside. Any comments, clue, ideas, suggestions...please, this thing has been a thorn on my side for the last month. Please help.   streak Posted on Monday, December 30, 2002 - 03:01 am:    Believe it or not I was going to ask you to check the TPS. At 75mph the trottle and TPS are in a particular position, the TPS is a potentiometer that may have a problem in this position. Dont want to get your hopes up too high but I am sure the TPS will do the trick. www.worst4x4.freeservers.com   Joseph E. Pineda (Jedpineda) Posted on Monday, December 30, 2002 - 10:27 pm:    Thanks streak, I'm hoping the TPS is the cure. I actually got it in today, but Roversnorth sent me the wrong TPS, they sent me the one for a 4.2 RR, the same one my 95 4.2 uses. I just returned it and order one from DAP, its half the price Roversnorth charges. We'll soon find out.