Rookie to this site needs help! - 986 Forum - The Community for Porsche Boxster & Cayman Owners

cjweiss · 10-10-2008, 06:37 AM

Yeah, the first thing I thought of was the most obvious...gas...but tank guage shows 1/4 tank and on board computer shows 81 miles left...probably unlikely that both are wrong but I am going to add more just to be safe...again, car turns over (cranks) as normal. I just want to eliminate the possibly easy stuff first hoping its a fuse type thing before tearing the car apart and starting with normal progression...checking spark/gas etc. If I had to guess I'd say the fuel pump either went or is not getting a signal. Thanks to all who have responded trying to help me...keep those ideas coming...they are appreciated!

Topless · 10-10-2008, 07:50 AM

Out of gas? These cars don't like to run below 1/4 tank. Sometimes the fuel gauge is off. Bad ignition switch?

CJ_Boxster · 10-10-2008, 09:35 AM

Sorry CJ, (no-relation) I think your going to have to start looking for reputible Indy Porsche Mechanics now, cause things like Compression Testing and Fuel Pressure readings are alittle beyond the average DIY'er unless you have the pressure gauges and the williness to get greasy & constantly run back and fourth from the engine bay to the drivers seat over and over again till u find the issue.

Jaxonalden · 10-10-2008, 11:44 AM

Cjweiss,

Did you pull a plug yet? After spinning over the motor you should be able to pull one out and see a wet plug, fuel soaked. If its dry you have a fuel problem, wet and you have a ignition problem.

Lil bastard · 10-10-2008, 12:37 PM

Was your car recently wet? Washed? Left outside in the rain? Wet carpet, esp. under the drivers seat?

cjweiss · 10-11-2008, 08:37 AM

No, car wasn't wet, it's a perfect weather driven car only. I have not dismantled this car to get to the motor which I was dreading having to do, to do any testing. I think I will see what a scanner picks up first...if anything. Thanks guys.

rick3000 · 10-11-2008, 08:43 AM

Accessing the engine takes less than ten minutes, and in very easy, so I wouldn't worry about that. While your back there check your drains (search for instructions), it is good idea to do so occasionally.

cjweiss · 10-11-2008, 10:05 AM

Quote:

Originally Posted by Topless

Out of gas? These cars don't like to run below 1/4 tank. Sometimes the fuel gauge is off. Bad ignition switch?

Hey Topless, I finally got the time to do something with my non running car since I had it flat bedded back home. Put gas in it and it started....you were right...guage showed 1/4 tank with 81 miles left on trip computer. Please share with me what you have expeirenced to know that these guages can go off and as you say, "don't like to run below a 1/4 of a tank". I'm sure I've been to a low fuel light in the past and never had a problem before. Obviously, I must have been bone dry as even the flat bed ride home didn't move any gas around to re-start it...you the man!!!

rick3000 · 10-11-2008, 11:09 AM

Some Boxster's have problems with the fuel gauge sticking. So when you fill up the tank is full, but the gauge gets stuck at 3/4 full. And the same thing can happen for low fuel. The gauge gets stuck at 1/4 tank, but their is less gas than that.

I have noticed that the OBC fuel gauge is based on your OBC average mileage. So if your OBC average mileage is very high (say from a lot of freeway driving), and then you go driving around town, the OBC may be giving you an estimated range based off your average MPG but not your actual MPG.
I'm glad you got it fixed and wasn't anything serious! My dad used to run out of gas all the time doing, "aerodynamic testing," in his 944.

cjweiss · 10-11-2008, 11:45 AM

Thanks Rick...I guess I'm still in shock that it's running...I must admit I'm a little paranoid about driving it right now but that will pass...again, thanks for taking the time to help me!!

SoCalKen · 10-12-2008, 07:02 AM

if you have a sticky fuel sensor what is involved in getting it fixed, (expense wise)? I have been having an issue with not being able to fill the tank with fuel because of what I thought was an air lock issue. sometimes at 1/4 tank I can only get half of what I think should go in and then the guage reads only 3/4 full. However after reading this maybe my guage sensor is totally wrong. I think the problem really is more of an air lock issue with mine as I can drive a little and then get more fuel in. To fill it up. Possibility is both problems are in play here.
Ken

Topless · 10-12-2008, 12:54 PM

That was easy!

The fuel gauge on these cars is somewhat unreliable

. A little German quirk. Sometimes it sticks at full, sometimes the float gets soggy and never really reads full (mine). You can change it out but the word on the street is that the new ones aren't much better. To overcome this I just reset my trip log at every fill up. Once I log about 250 miles I know the gas gauge means business. Time for gas.

You would think they could figure out how to solve this simple problem.