99 2.5 Starting Problem.

[Leigh]

For the past Month or so, Though it cranked right up effortlessly, from a cold start; after stopping someplace for "awhile" it became problematic, requiring rapid pumps of the pedal to start.

Yesterday, initially started, & drove normal, but after 2nd stop it wouldn't start.
Tried all the "usual" (Pedal-up, Pedal down, Pump pedal-)--, cranked strong, but no "attempt" of ignition. After sitting 45 minutes, it stared "normally", & continued to start after several more stops.

Did the same again today,

Actron Pocket Scan, & with engine running, got following Listing: "02 Sensor", "02 HTR", "COMP", "CATALYST", "EVAP", "EGR"; but no Code #'s

Problem seems to be intermittent fuel "starvation" ; similar to the symptoms of Vapor -lock, but has gotten progressively worse. Possibly Fuel-pump "beginning to fail???

Regards,
Leigh

 

[Leigh]

UPDATE: Pressure Check.

System failed to hold pressure Key=On / Eng. = OFF ( Maintained 62 PSI running at idle).

Determined that Fuel pump Check-valve is not working, so needs Pump module Replacement.

Since the system is not maintaining fuel pressure because of the Check-valve, I still don't understand why it would start right up cold, but not after it's been driven "awhile"???

 

[tomw]

As noted on the other site, I would suspect plastic parts warping when warmed up, but just thought of the computer adding extra fuel when cold. The mix is enriched when cold to help cold combustion & mix. Maybe there's better flow, and some 'pooling' in the intake that helps.
Dancing on the gas pedal does nothing to the mix, there's no accelerator pump to squirt more fuel. Holding the pedal down a bit from base idle might be effective if the IAC is being unhelpful. The repeated cycling of the ignition should get fuel into the fuel rail, and make warm starting easier if it has drained back, and doesn't want to start on the reduced fuel flowed when fully warmed up.
tom