If the fuel pressure was OK when you checked the regulator, the fuel
pump is probably not to blame.
  An exhaust leak can sometimes cause air to come into the exhaust
system causing the O2 sensor to give misleading readings.

Larry A.

Geza Polony wrote:

>Hey all,
>
>I have another exasperating cold start/idle problem with  my '84 1.9. Cold
>starts hard, with RPM dropping to very low or zero and engine stalling if I
>don't keep revs up to 2500 or so. When warm, idle will drop down to 300,
>then back to around 900, sometimes stall.
>
>What it ISN'T: fuel pressure regulator, fuel filter, bad compression, idle
>stabiliser, plugs, wires, dist. cap, rotor, vacuum leak, AFM, throttle body,
>low battery voltage at startup, aux. air regulator, bad ground, Temp II
>sensor, O2 sensor, cat, muffler. All these have been checked or replaced.
>
>Guesses: Hall Sender going bad? Fuel pump bad? (buzzes, but car runs fine at
>high speed.)
>
>There was a coolant leak at the left head before Bar's Leaking it. One plug
>(#1) showed signs of ashing up.
>
>There's a small exhaust leak someplace.
>
>Red alternator LEDs are on when starting/up to 2K rpm. Charges fine (13.9
>volts @ idle.)
>
>Thanks for any help you can give me on this one.
>
>
>Geza
>
>
>