Boxster cranks but does not start

[pieter1]

Hi this has been beat to death but I need help please.
Car cranks but will not start. I verified I have spark, fuel pump relay is latching when ignition is in on position. If I put power direct from the battery to the pump it works. But if I plug the connectors back there is no power to the pump. Any ideas next step is CPS (luckily I have one spare as well as two Cam position sensors)

[Gilles]

Originally Posted by pieter1

Hi this has been beat to death but I need help please.
Car cranks but will not start. I verified I have spark, fuel pump relay is latching when ignition is in on position. If I put power direct from the battery to the pump it works. But if I plug the connectors back there is no power to the pump. Any ideas next step is CPS (luckily I have one spare as well as two Cam position sensors)

Have you checked the fuel pump relay..?

[pieter1]

Gilles just a question if the relay latches (click) does this means it is working or can it still be faulty

[newBgeek]

Originally Posted by pieter1

Gilles just a question if the relay latches (click) does this means it is working or can it still be faulty

No. A clicking relay does not mean it is working. I made this mistake when I replaced a radiator fan (checked the relay first to make sure it clicked at the advice of another forum thread) only to find that the fan was fine and the relay was the issue. ARRRRGGG!!! Then, a couple months later the other radiator fan failed (this time confirmed the relay actually worked before replacing). I replaced it with the fan a took from the other side, but it only lasted a couple weeks before it failed again. Double-ARRRGGG!!! Anyway, now I have 2 new fans, and I keep a spare relay just in case.

You can bench test the relay if you have a multi-meter, or just swap it with a known good relay.

[pieter1]

Thanks guys tonight I will put my 996 fuel pump relay in the Boxster

[Gilles]

Originally Posted by pieter1

Thanks guys tonight I will put my 996 fuel pump relay in the Boxster

A couple of days ago HealthServices posted how to bypass the fuel pump relay (hot wired) you may want to try it before you buy a new relay..

[Gelbster]

Originally Posted by pieter1

Car cranks but will not start. I verified I have spark, fuel pump relay is latching when ignition is in on position. If I put power direct from the battery to the pump it works. But if I plug the connectors back there is no power to the pump. Any ideas next step is CPS (luckily I have one spare as well as two Cam position sensors)

So why not change the CPS??
"When the CPS fails, I think the ECU 'thinks' the engine is not rotating. Therefore there is no need for any fuel.Therefore the fuel pump relay gets no signal.
CPS is not very expensive. About $90 in USA. The part number for mine(but verify for yours) is:
BOSCH - 0261210204 "

[pieter1]

Guys thanks for the help it was the fuel pump relay. I put the 911's relay in and pump came on. O I did not mention the car is a true barn find out of Iowa stood for 9 years in a barn on a guys farm. I and getting her out of her coma. Fuel pump was frozen (discovered when trying to drain the gas). Had mice in there but wiring is all good, interior is destroyed. 47000 miles and a 3,4l Carrera motor in M96/01. Body and paint is stunning. plastic window is out.

[Gelbster]

Thank you for letting us know the outcome. Disappointingly some people just drop the thread when they find the solution.
The interesting part of the diagnosis that we often rely on was absent from your description:
" Does the tachometer needle bounce when you crank ?"
In theory ,it will bounce if the fuel pump relay is defective..but
it will not bounce if the CPS is defective.
The OEM fuel pump relay seems to be Wittrin or KAE a.k.a. KAEHLER # 2.408.120
Porsche part number 996 615 101 00
Price around $10 for a "Made in Germany" from Pelican . It has one of the 4 pins undersize so generic 4 pin 15/40 relay would not be a substitute. Carry a spare?
Pelican Parts - Product Information: 996-615-101-00-M504

[pieter1]

Sure do now since I have two P cars Ordered from Pelican. And yep the tack needle did jump when I cranked it that's why I ruled out the CPS.