Strange Starting Problem Warm Engine

[cerealboy]

I purchased my 2005 ZHP with 140,000 km (87,000 miles) on the clock back in Sept '23 with no winters on the body here in Ontario, Canada. The car would cold start in the morning with just the "turn of the key" and after a few minutes display a lovely smooth idle...warm up the engine to operating temp. still all smooth acceleration and idle...turn off engine, wait 10 or 15 minutes, start up with just "turn of the key"...All systems normal.
BUT, turn off engine, leave car for 1 hour, starting took at least 4 turns...when engine started, it stumbled at around 500 rpm for about 5 or 6 seconds then assumed a perfect idle and normal running. NO CODES DISPLAYED.

I thought back to some of my old cars with carbs. especially when they flooded...they displayed the same kind of symptoms.

So,

I took off the plastic engine covers, pressurized the fuel rail (turn the key to position 2 but don't start), then pushed down the schrader valve on the end of the fuel rail, it squirted fuel, so the fuel pump was ok. Pressurized the fuel rail again then let her sit for 1 1/2 hours...then pushed the valve...nothing! Pulled the spark plugs out and using a 1/2" tube smelled each cylinder thru the spark plug hole...Number 4 hole smelled a bit like gasoline.

Pulled off the electric rail to the fuel injectors with a wide pry bar...pulled out the fuel rail with all 6 injectors in place. Taped 6 typical prescription vials, 1 each on each injector, pressurized the fuel rail again then let her sit for 1 1/2 hours. Guess what...I found fuel in #4 and slightly less in #5 pill vial. Problem Found.

Replaced the 2 faulty injectors (attach the clip first to the injector, lube o-rings, then push onto the rail to engage both sides of the clip) Lube all the o-rings going back into the intake manifold, then re-assemble everything.

Next...A complete oil/filter change to complete the job.

[danewilson77]

Test

[Oli77]

That's some good investigating and fixing right there!
I wouldn't know what to do with the schrader valve. Last time I suspected a bad fuel pump (it was), I looked at that shinny round thing and didn't know how to deal with it. Seems to be screw cap?

[ZHPizza]

Nice! I went through the same thing when I got my car -- left the fuel rail pressurized and laying on some paper towels, came back and saw which ones had leaked fuel onto the towels.

I actually sent them off to be rebuilt only to have the same issue, so still had to get new injectors in the end. Just a warning to others!