Hot Starts '83 3.0

[PK911FL]

I've read many posts but lacking direction on my next steps after replacing fuel filter and accumulator. I haven't seen any posts specific to my issue with timing and idle, so any direction or help is appreciated.

Problems:

1. Cold Start - Took 5 mins of 2500 rpm to keep car running without throttle. Ran fine after. Once warm keeps at 900rpm at idle

2. Hot Start - wouldn't restart for at least an hour after warm

Fix #1

1. Replaced fuel filter and accumulator

Results

1. Cold Start - Much better, still sputters a bit, 5-10 seconds at 2500 and let off, the car stays running, idles at about 500 rpm until warmer, then stays at 900rpm

2. Hot Start - Wait 5 minutes, car restarts no issue, idles at 900. Wait 15 more minutes, no restart. Wait 10 more minutes, no restart. Wait 30 minutes, restarts but needs 10 seconds of throttle and it ok 500-900 rpm.

Also noticed when I wait the 30-60 minutes and restart, it has died after a minute, and then won't restart unless I wait a bit.

[PK911FL]

Nobody?

[pete3799]

If you've read many posts you'd know that with out some fuel pressure readings it's near impossible to give any advice with your problems.

[Zuffenwerker]

Hook up your fuel press. Gauge and record CCP, WCP, System Pressure, and leak test results. I’m guessing it fails the leak test based on your description.
Let us know if you need specs

[PK911FL]

Originally Posted by Zuffenwerker

Hook up your fuel press. Gauge and record CCP, WCP, System Pressure, and leak test results. I’m guessing it fails the leak test based on your description.
Let us know if you need specs

Thanks, this is the guidance I was looking for. Specs would be great, haven’t done a fuel pressure check on a 911 yet. I have a Bentley manual as well.

[PK911FL]

While I’m waiting for my pressure tester to arrive. I started her up and after about five minutes of throttle she was able to stay on. Took her for a drive got warmed up, got back home turned off the car. Turned on immediately after and it started up. Waited five minutes, wouldn’t start. Removed the airbox cover and pushed up on the valve, and it started right after that. I did notice a hissing sound, which I tried to capture in the following video. Is this normal or is the sound of a vacuum leak?

https://youtube.com/shorts/-ntXQK6TFpA?feature=share

[wakeupct]

Probably the check valve on your fuel pump is not holding pressure in the line. This causes fuel to vaporize after say 15 min and then it’s hard to start. Fuel accumulator also helps with this but you said you replaced already.
But that’s just a guess until you get the pressures checked. Also the issue on warmup is not likely a check valve issue so maybe there’s another issue.
Good luck!

Pete


Sent from my iPhone using Tapatalk

[PK911FL]

Pretty sure I can confirm the airbox has blown. 2 screws were popped up, and one doesn't really tighten. After screwing them down, it has less "wiggle", but overall I think its blown. I would guess this is the source of my problems.