986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - HELP!!! rough idle missfires after work on ps

stelan · 11-12-2015, 06:09 PM

Hi, I need some advise on this thing.
This is 99 boxster new to me, just bought it a while ago, when i got it it had a typical burned by headers power steering high pressure line and previous owner installed a banjo fitting with clamps that was leaking, so I removed the entire line and replaced with a new one, after doing this the car runs very rough at idle like is running on 4 or 5 cylinders and wants to stall on idle, the car was running great before I replaced the power steering line.

My first impression is that it has a vacuum leak and I checked everything that I disconnected and removed over and over:

plastic tube from airbox to throttle body
snorkel clamp
clamp from tube to throttle body
little rubber hose under Throttle body
two little plastic hoses that insert into the boots
four clamps on the intake boots
gasket on passenger side intake manifold as I have to loosen it to remove ac compressor bolts to move it out of the way to get to the power steering line

additional things that I did that can provide more clues:

cleaned the throttle body with solvent and a brush (did I brake it?)
cleaned all the plastic intake tubes
connected and reconected the two electrical plugs into the throttle body

I did not disconnected the battery at all during the process

One thing I did also was trying to start it without the j-shaped plastic tube that goes from throttle body to aux air pump and of course it did not start, I forgot to install it and then I noticed it, then installed and it started right up but rough.

I wiggled the intake manifold a lot when it was loose and perhaps I disconnected something else like injectors or? I visually can't find anything wrong with it.

When running I sprayed a little engine starter on the probable sources of leaks and the idle does not change except when spraying close to the air box, which I assume is normal.

The codes I'm getting with my cheap obd2 scanner are all missfires

P1319 GENERAL MISSFIRE
P1314 MISSFIRE CYL 2
P1316 MISSFIRE CYL 4
P1313 MISSFIRE CYL 1

Please note that I can not take it to a mechanic since I live up in the mountains in central mexico (I live here for half a year since I'm semi-retired) and mechanics hera are far away and do not know anything about porsches, lol.
anyway... HELP!!!!

11-12-2015, 06:09 PM	#1
stelan Registered User Join Date: Oct 2015 Location: Austin Posts: 395	HELP!!! rough idle missfires after work on ps Hi, I need some advise on this thing. This is 99 boxster new to me, just bought it a while ago, when i got it it had a typical burned by headers power steering high pressure line and previous owner installed a banjo fitting with clamps that was leaking, so I removed the entire line and replaced with a new one, after doing this the car runs very rough at idle like is running on 4 or 5 cylinders and wants to stall on idle, the car was running great before I replaced the power steering line. My first impression is that it has a vacuum leak and I checked everything that I disconnected and removed over and over: plastic tube from airbox to throttle body snorkel clamp clamp from tube to throttle body little rubber hose under Throttle body two little plastic hoses that insert into the boots four clamps on the intake boots gasket on passenger side intake manifold as I have to loosen it to remove ac compressor bolts to move it out of the way to get to the power steering line additional things that I did that can provide more clues: cleaned the throttle body with solvent and a brush (did I brake it?) cleaned all the plastic intake tubes connected and reconected the two electrical plugs into the throttle body I did not disconnected the battery at all during the process One thing I did also was trying to start it without the j-shaped plastic tube that goes from throttle body to aux air pump and of course it did not start, I forgot to install it and then I noticed it, then installed and it started right up but rough. I wiggled the intake manifold a lot when it was loose and perhaps I disconnected something else like injectors or? I visually can't find anything wrong with it. When running I sprayed a little engine starter on the probable sources of leaks and the idle does not change except when spraying close to the air box, which I assume is normal. The codes I'm getting with my cheap obd2 scanner are all missfires P1319 GENERAL MISSFIRE P1314 MISSFIRE CYL 2 P1316 MISSFIRE CYL 4 P1313 MISSFIRE CYL 1 Please note that I can not take it to a mechanic since I live up in the mountains in central mexico (I live here for half a year since I'm semi-retired) and mechanics hera are far away and do not know anything about porsches, lol. anyway... HELP!!!!