Confused Turtle

I have been working on this 99 Boxster for a while now. I finally got the motor back in but having issues trying to get it started. It at first wouldnt even try to turn over. I jumped the starter relay and it would attempt to start. Then found that it had no fuel pressure so i jumped the fuel pump and I got fuel pressure. I then replaced both relays but still will not do anything unless they are both jumped. I've also notice im not getting anymore movement from the tach or the spedometer when I try to start it.

I'm not sure where to go from here. I have some ideas. Does anyone have any idea where i should start with figuring out why I need to jump all these relays just to get it to attempt to try and start?

Dllrd23

when you say you are jumping the relays are you using power from the control side to jump or are you applying power from an outside source? Do you have power on the control side too if so? If not (and you probably have already done this) check the fuses that power the control side. If you have power on the control side then look in to what provides the ground on the control side for those relays. Probably the computer after seeing ign switch input. Give some more details about the car 99 Boxster. I assume 2.5l engine. Std or auto? Any mods? Does everything else seem to work?

Starter986

I may stand corrected... but from what I've read upon the forums... if the RPM guage isn't moving that points to a bad crank position sensor. Best wishes on the outcome.

Confused Turtle

I am using it from the control side and jumping it that way. It is a 2.5 and it's manual. No mods aside from the stereo but I disconnected all of that when the issue started. I did also notice that I'm having a few other issues. Like the windows are not refusing to move and the key will only lock the car and won't unlock it.

Confused Turtle

I also thought the same thing so I pulled a CPS from another vehicle and there are no changes.

Confused Turtle

Update on this, I had a porsche code reader plugged into the OBD port and found that it wasnt reading the immobilizer, i checked the fuse and the connections to it and both seem to be fine. Is there another fuse that runs to the immobilizer that i can check or a pin test to see if its gettign any voltage?

Dllrd23

according to my diagram check e1, b8, f5, and c3
e1 is hot in off, acc, run, or start
b8 is hot in run or start
f5 is located in the current distribution block and hot all times
c3 is hot all times

did you swap the ecm?

current distribution block is in passenger footwell on the luggage compartment wall.

Dllrd23

What codes related to the immobilizer did you get?

pilot4fn

Did you check the fuse at the side of the actual immobilizer as well? I have a 2001 Boxster and it has one fuse also at the exterior outside wall of the immobilizer it self.

TheAdoptedGuy

Looking to buy a 1998 boxster as my first Porsche and it’s having the same issue. Electronics start but won’t even try to start or bump the engine. Has this weird buzzing noise. Had some water in the front with the battery. Has 27,800 miles. Just messaging so I can get some ideas before I buy this and if y’all come up with an idea.

NuttyProfessor

I have friends that have owned Boxsters and they've experienced flooding that killed the module under the seat. Does this happen to be a flood car? Have you tried getting a dealership to test security system? Some people have also noted great success working with independent locksmiths that have Porsche diagnostic systems. Seems like that would be a good first start.

mikefocke

Water up front under the hood where the battery is mounted fairly high? If that happened, how was the rest of the car and every electrical connection not also flooded?

Given what you have said, that car is good as a parts car perhaps if you have the time, space and skills to strip it. A flooded car is often long term trouble as you trouble all the connections that go bad over time.

tcora

24 year old car, clearly not driven much, that won’t start. Ask the seller to put a new battery in it. If that solves the problem, maybe you’re OK. If that doesn’t, keep looking. It’s not like Boxsters are rare.