boxster newbie

my 97 boxster, has just had a new fuel filter, air filter, sprayed the MAS, ran 150 miles, on a hot day, wouldn't start until I applied throttle, got home and put a fuel pressure gauge on the rail, got it running and read, 3.5 -3.8, wich I assume to be normal,it held the pressure when turned off,any sugestions would be cheerfuly accepted.

968workaholic

Check the evap (fuel vapor) system

Macster

P1124/P1126: Fuel enrichment at its limit bank #1 and bank #2.

Any pending codes?

The failure is at low engine speed, with the engine RPMs below 880.

Possible causes: intake system leaking. Fuel pressure too low. Fuel injectors contaminated. Volume supply of fuel low.

Based on what you wrote fuel pressure is acceptable. Engine idling: 3.3 bar +/- 0.2 bar. Engine off: 3.8 bar +/- 0.2 bar.

(Be aware that the fuel test port seal is not to be reused but should be replaced.)

My WAG is there an intake system leak. This can take several forms.

Without knowing the car's history/miles unless you or someone was recently working on the car around the intake I can offer the following to check.

First check the oil tube filler cap. The leak is at low engine speed (idle speed) leak. I've had to replace the oll tube filler cap on my 2002 Boxster two times now. Believe it or not the cap (seal) wears out and leaks air at low engine speed. Actually the cap if it leaks at all leaks air all the time but at higher engine speeds the amount of air it lets in is small compared to the amount of air that is coming into the engine via the normal route and the leak doesn't matter.

With the engine idling see if you can move the cap about and if the engine reacts. In a quiet place I could hear the air leaking past the cap.

The other possible explanation is the AOS (air/oil separator). These based on my experience last anywhere from 80K to 120K miles but it is not not unknown for one to fail at fewer miles. The usual "test" to with the engine running is unscrew the oil tube filler cap and remove the cap probably won't be of much use for it doesn't read like the AOS has gone that bad yet. But you can try this. The one time I did this the cap was impossible to remove against the pressure difference.

If you can remove the cap this does not let the AOS off the hook. It may not have deteriorated to the point that it produces an excessive low pressure in the crankcase yet.

If you get the cap off the engine will react which is normal. The engine controller will adapt to the big air leak the absent cap represents in just a moment or two. Then when you put the cap back on the engine will react again and again the engine controller will (re)adapt and the engine should run ok.

Bush Pilot

I’m getting these codes. The Bentley is leading me to the fuel pump relay and/or the oxygen sensor on cylinders 1-3. I plan to replace the relay since I suspect that that’s easy.

Bush Pilot

I replaced the fuel pump relay but the codes came back. I guess it's time to start thinkiung about an 02 sensor replacement.