hard run=hard start

[boxstermao]

99 C4 coupe tip, its been 1 month since i replaced my fuel pump to cure a starting issue after a hard run. but unfortunately the problem is back.

it now takes me 3-5 starts with a bit of throttle to start the car after a run. I get no CEL, no codes when i hook up my durametric, any ideas please what to do next short of a piwis tester? TIA

[CJ_Boxster]

how does it run after you finally get it to run after a hard run? Get your compression checked

[1999Porsche911]

What plugs are you running? If you have small leak in an injector, it will not effect driving, but after shut down, it will leak until pressure in the fuel line is depleted, causing it hard to start. If you have the ability, hook up a pressure gauge to the fuel line and see if it drops overnight.

If it is not hard starting after it sits for a long time but only within an hour or so after shut down, one cause is running too rich which can also be caused by leaky injector(s) that may not leak enough to effect normal driving.

[boxstermao]

the car runs fine when i get the car to start. i will try you suggestion thanks for your replies, will update soon. by the way, i use the oem plugs, wat is their relevance to my problem?

[Loren]

How many miles?

Have you tried cleaning the throttle body with carburetor/fuel injector cleaner?

[boxstermao]

1999porsche911,

ive hooked up a pressure guage but get no reading with the engine off. can you elaborate how i can check fuel pressure after i leave the guage connectd overnight? tia

loren,

my car has 16,000 kms only. run only as a weekend toy. i have replaced the fuel pump and regulator as an attempt to isolate the problem to fuel delivery. help pls thanks.

[boxstermao]

after pouring hours trying to figure out the problem, we insolated the problem as a fuel delivery issue. and we went back and removed the fuel pump we installed earlier. we noticed that the fuel hose was not properly installed as we only copied how the old one was installed. i ran the car hard twice afterwards and let it sit for about 30 mins to simulate the problem, and she starts right up. hope this helsp other guys with the same symptoms.