Shudders while cranking, not starting

[jakevance99]

Hey guys, I just bought a 1999 Porsche Boxster about a month ago, and it has ran like a dream until today. Yesterday I detailed the heck out of it, put some oil treatment in it, fixed a headlight, and drove it around. It behaved totally normally, if not better than it normally does. I went out to start it this morning, and it just cranked and cranked. I gave it a little gas while cranking, and it started to catch like it was gonna start, but then I saw some white smoke. I took the engine cover off and was looking around. Everything seemed to be good from what I could see. I had a small oil leak, but I had already known about that. I cleaned out the air filter good, and topped off the oil. I kept cranking it for a couple seconds periodically just to see if I was making any progress. I had to go to work so I put the covers back on and tried to start it one more time. I noticed this time that as it cranked, the whole car kinda shook/shuddered. Im gathering that the lack of ignition could be a crank position sensor, or a fuel pump/ fuel fuse issue, but the rough cranking has me worried. there weren't  any metallic flakes in the oil, and it didn't sound like metal on metal grinding, it was just rough. any help or advice on it would be great, I'm new to owning a Porsche, and while I've worked on cars before, this Porsche is a new kind of beast. 

[JFP in PA]

Welcome to RennTech

 

Start with the basics:  Does the tachometer "bounce" while you are cranking it over?  If it doesn't , you may have a bad crank position sensor.  If it does bounce, check to see that you have both fuel pressure and delivery.  No fuel, no fire.................

[jakevance99]

I went home after work and cranked it for probably 5 seconds and it started right up. I’ve been driving it around for the whole evening without anything unusual happening. I’m gonna replace the fuel pump still, I’m pretty sure that was causing the trouble starting. I think the shuddering might have just been a low battery, I haven’t noticed it since. Thanks for the advice! I’ll definately use it if my plans to fix it fail 

[rockhouse66]

Did "detailing the heck out of it" include spraying cleaner and water in the engine bay?

[jakevance99]

No, I didn’t even touch the engine bay. It’s such a hassle to get to, I just tried to steer clear of the intake on the side, and the soft top as best as I could. Most of the work I did was on the interior