99 No start issue.
 

I just picked up a 99 Boxster and am trying to bring it back from the dead. It was last running in the fall. The car would start and run for about 3 seconds, and then not fire again until some hours later. I took a chance and replaced the Crank sensor (no tach movement when cranking). Then the car started for like 20 seconds with me feathering the gas and backfired and died. I looked under the car and there was a puddle of fuel under the passenger side from an exhaust junction. I checked fuel pressure and it was great, even after sitting for 30 min it still held. I took the throttle body T section off from between the intakes and there was fuel in both intakes and the T. My guess is some sort of vacuum issue that’s pulling fuel into the intakes? Any ideas? Thanks in advance!

Start with the basics:
Replace spark plugs. Clean the TB. Check your air filter. CHANGE THE OIL IF YOU HAVEN'T ALREADY. (Old oil is bad oil, especially if you've been over-rich). Check your cam timing. Change the fuel filter.

My guesses would go;
stuck injectors.
Fouled plugs.
Air obstructions.

Really, hit your basic troubleshooting methods: fuel; check. Air: check. Spark; check. Timing; check. Then it runs.

Sent from my SM-G970U using Tapatalk

Thanks. Planning on new plugs and oil tomorrow. The fuel in the intake is just odd.

I have great fuel pressure
Spark is great
Air filter is clean.

How nasty is the fuel? any chance of water in it?

It doesn't seem bad. It has less than a quarter tank. Today I plan to:

change spark plugs
change oil
add 5 gallons of premium fuel
double check all vacuum lines before installing intake T

All of this still doesn't explain the fuel in the intake T, but I'll take my chances and will update.

Thanks

I think maytag hit the nail on the head. Go to the basics. I had a crank no start a while back. First check for spark, then check for fuel pressure, check for air leaks. If these pan out then dig a layer deeper. Could be bad fuel as suggested if it has set awhile. Could also be injector issues or the pressure regulator but if you are seeing fuel in the intake I wouldn't think so. Could also be crankshaft sensor but you can check the connector and see if it is reading the recommended voltage. It's a little hard to get to but can be done.

You'll just have to be methodical and work your way through it but you'll get it. Let us know when you find out the culprit. Good luck.

Fuel in the intake shouldn't be what you get hung up on. You flood the motor when you fail to burn the fuel. That'll account for fuel EVERYWHERE..... hahaha

You may consider a bottle of "stabil" or "heet" or something like it when you put that gas in the tank. And change that fuel filter.

Sent from my SM-G970U using Tapatalk

99 No start issue.
 

Weird. Still working on it.

If the IMS bearing went bad, that would explain bent valves. Pull the oil filter and or the pan and look for metal bits. Did you witness it running last year?