Car won't start, no fault codes

[Sheriff John]

I have a 1998 boxster, with 147K miles on it. I drove home one night, the next morning the car cranks but won't fire. I don't smell gas.

Here is what I've done so far.

1. Replaced the ignition switch. (the spring was weak and didn't want to return without a helping hand, so it needed that anyway)

2. I can hear the fuel pump but have not tested it. The fuel filter has about 20k miles on it.

3. Tested the DME relay and the FIO (fuel injector/ignition coil/O2 sensor) All OK

4. Fueses look good. Fuel pump, DME, etc.

5. Was following instructions on from the Bentley manual. Section where says turn ignition on and check continuity to ground at terminal 85 on DME Relay. It says if I don't have continuity, I'm not getting a signal from the DME. I checked the wiring from the relay block to the ECM connector and it's good. So, to me, it's telling me that something is wrong with the ECM. BUT, I'm not getting any fault codes at all.

don't want to go out and get a new ECM unit without being sure.

I guess I could check the fuel pump. Although I hear it when I turn on the ignition, I haven't proved that's working. I could pull the filter and see if it's plugged or test the fuel pump to see if it's really working.

Any ideas or help?

Thanks,

SJ

[Loren]

:welcome:

Unless you are positive the relays are working start by swapping them with another car that is working.

[Sheriff John]

Thanks for the welcome. Been visiting for a long time, just never posted.

I swaped one of the relays, but will swap out the DME relay too. I hear them click and they seem to check out electrically, per the manual, but it's good to make sure.

Do you think swapping out the DME/ECM unit with another Boxster (same year) would work or does it need to be programed?

Swapping parts sounds like a good idea. Want to make really sure before I invest in another DME unit.

thanks,

SJ

[Loren]

No swapping DME won't work because you would need to reprogram the immobilizer each time.

You should however check to see that the connections to the DME are tight. I had one once that was 3/4 of the way unplugged.

[pk2]

Has your car gotten soaked recently? I've had my car flake in every way imaginable. The real stumper is a soaked black box under the driver seat. If it's damp down there, thats probably your trouble (been mine 3 out of 8 times)

Regards, PK

P.S. I f it is, get it out yesterday and dry it out, you may save it (I'm 2 for 3 on that count).

Edited April 14, 2008 by pk2

[Sheriff John]

Has your car gotten soaked recently? I've had my car flake in every way imaginable. The real stumper is a soaked black box under the driver seat. If it's damp down there, thats probably your trouble (been mine 3 out of 8 times)

Regards, PK

P.S. I f it is, get it out yesterday and dry it out, you may save it (I'm 2 for 3 on that count).

No, it didn't get wet. I don't think this is the problem, but at this time who knows! The car still cranks so I hear that if the immobilizer is causing the car from working, it wouldn't crank. I changed (moved around) the relays to no avail.

I may have to get it towed to a shop. I'm running out of options. I'll check the fuel pump and filter, just to say I did it.

Maybe now's the time to put a 3.4 conversion in this thing! :D

[juniinc]

bad fuel pressure regulator can cause this, if its not the DME

[Sheriff John]

:rolleyes: Well, it turns out that it was the fuel pump relay. I don't really understand it because I'm pretty sure that I swapped that relay and I could also hear the fuel pump work when I turned on the ignition. The deal is that I gave up trying to fix it myself and had it towed to Vison Motor Sports, here in Orange County, CA. It took them a few hours to find the problem but that's what they said was the problem. I think there was some black magic done too.

Had the clutch replaced while it was there. I haven't been lucky in this department. At 95k I replaced the orignal clutch and mass fly wheel. At 147k the oil that is imbedded in the mass fly wheel oozed out and trashed the clutch. So another clutch and mass fly wheel with only 52k miles on it? bummer, but the car feels so good with a working clutch. :D I didn't realize how bad, bad was!

thx for all the input.

SJ

[RFM]

Contains two mass flywheels oil in the US ?

[Sheriff John]

Sorry, I don't really understand your question. I don't know if there are any differences between the US and EU clutches and flywheels. I would not think so.

fortunately there is only one Dual Mass Flywheel on the Porsche. (fortunately, because they are expensive!) From what I've read, Dual Mass Flywheels incorporate the normal flywheel with vibration dampening. They also make shifting more smooth and easier. Here is a link explaining a DMF. http://www.aa1car.com/library/2004/bf40459.htm

SJ

[wvicary]

Contains two mass flywheels oil in the US ?

I think what RFM is asking is if that the vibration dampener of the DMF contains oil like some engine mounts. To my knowledge it's just a solid,rubber coupler.