1998 Porsche 986 crank but won't start !!

[Troyfrommars]

Hi there,

 

I really need your help with my boxster 986. The seller informed me that this car won't start after sitting in the garage for 5 months. At first I thought it's the battery problem, so I replaced the battery. the engine will crank but no fire at all. Then after some research I found out it could be a CAMSHAFT or CRANKSHAFT sensor problem. Then I bought a scanner, found code P1397 which is a camshaft position sensor bank 2. Someone has mentioned on 986forum that a crankshaft position sensor could also throw a camshaft code, but I chose to go with camshaft sensor because that is what said on the scanner. I ordered an aftermarket camshaft sensor from pelican parts, and the part number is : 996-606-106-04-M18.

 

After install the sensor, still no good. However, the tach now starts to move a little, and 1 out of 20 times it will fire up but then die immediately. 

 

so now everyone, should I go replace the Crankshaft sensor ? or what else should I consider? Could it be a fuel pump problem? Will replace the fuel pump relay help ? 

 

Thanks everyone in advance !! 

 

Troy 

 

 

[crwarren11]

I would go through the troubleshooting process for fuel pump to see if that gives you any guidance. Relay is one possibility or the pump itself. My pump went out around 100k mi and 19yrs. I also replaced the crank sensor because I thought that was it. Nope...just the fuel pump. 

[Troyfrommars]

2 hours ago, crwarren11 said:

I would go through the troubleshooting process for fuel pump to see if that gives you any guidance. Relay is one possibility or the pump itself. My pump went out around 100k mi and 19yrs. I also replaced the crank sensor because I thought that was it. Nope...just the fuel pump. 

Hi Crwarren11 thanks for you reply, can you point me to a post that touches on troubleshooting fuel pump related stuff ? That would help a lot ! 

[crwarren11]

Here are a couple of links I used.  Let me see if I can remember how to post pics/documents here...

 

https://rennlist.com/forums/993-forum/925886-fuel-system-testing.html

 

https://www.renntech.org/forums/topic/34302-ignition-turns-over-engine-wont-start/

[crwarren11]

Fuel System Testing Part 1 Rev 1.pdf

 

Edited March 26, 2020 by crwarren11

[crwarren11]

Diagram

 

I can't remember what thread this was on here, but I saved an image when I was working on it.

 

Edited March 26, 2020 by crwarren11

[crwarren11]

After replacing the fuel pump it was obvious what the noise of the fuel pump running was supposed to sound like.  Since this was my first fuel pump job, I never knew before, but it is a very distinct noise you can hear either from the area under the hood near the battery, or some have suggested listening into the fuel filler with the cap removed.  To me it is a buzzing noise, kind of like one of those small drones makes (like the ones you would buy for a 5 year old, not the big ones for us adult children).  I did all the jumping methods for the relay, etc. and never got the noise.  Also tested the pressure at the schrader valve, which was 0 at all times.  What threw me off initially was that I kept reading the telltale sign of a bad crankcase sensor was that the tachometer would not bounce when trying to start.  Mine did not, so I thought that was it.  As I mentioned earlier, my sensor was fine.  Hope this helps...

[Troyfrommars]

6 hours ago, crwarren11 said:

After replacing the fuel pump it was obvious what the noise of the fuel pump running was supposed to sound like.  Since this was my first fuel pump job, I never knew before, but it is a very distinct noise you can hear either from the area under the hood near the battery, or some have suggested listening into the fuel filler with the cap removed.  To me it is a buzzing noise, kind of like one of those small drones makes (like the ones you would buy for a 5 year old, not the big ones for us adult children).  I did all the jumping methods for the relay, etc. and never got the noise.  Also tested the pressure at the schrader valve, which was 0 at all times.  What threw me off initially was that I kept reading the telltale sign of a bad crankcase sensor was that the tachometer would not bounce when trying to start.  Mine did not, so I thought that was it.  As I mentioned earlier, my sensor was fine.  Hope this helps...

thanks a lot man !! I will keep you updated. 

[flyingpenguin]

Crank Position Sensors on the bell housing are known to go bad. These are cheap and easy to fix.. Not suggesting you randomly throw parts at the problem but had this happen on several M96's (my own and others').