21st Feb 2014, 00:36
This is Larry. So glad that someone read my comment about correcting the high idle problem by replacing the OVP regulator, which governs the amount of voltage to the computer. Sorry I left out that the idle / OVP regulator lowers the high idle problem.
My current problems are the factory troubleshooting manual. My 89 420 SEL runs perfect except for the high idle problem I had. Now she won't restart when it's hot (80 degrees & above). I go to restart, but it only cranks, but if I pour a little gas in the throttle body, not touching gas pedal, it starts. If it doesn't start, trying again has been my solution for now, so the solution is study the trouble shooting factory manual. The potential cures so far are the fuel pump accumulator and fuel distributor? I have very little money, but I'm grateful that someone took my advice. If there's anybody with advice, contact me at 714 404 0184.
3rd Dec 2013, 12:35
Similar problem with an old Audi I had - one of the relays had a hairline crack in the solder, so after it gets hot, it won't start. Mine was a more centralised "engine control" relay; not very big.