Airflite40

I have been fighting a no start condition the last week on my S2

after a hard rain the car won't start. I changed the ignition module behind the drivers headlight since that seemed to get wet and the car started.
it rained hard again yesterday and today the car won't start. I'm not getting spark. My DME is not getting wet, swapped relays and nothin...

any ideas?

Lemming

More info? Is the starter engaging?

Airflite40

cranks but no fire. not getting spark

krystar

is coil getting input power?

Airflite40

do I measure that when cranking? across the leads to the coil I assume?

i was in a hurry this morning so I checked for spark betwen the cap and #1 plug.

I will check for spark from the coil to the cap (to rule out cap & rotor) and check for 12v across the coil when cranking?

thanks.

originalmotorhead

wiggle the reference sensor connectors.

Tom

Airflite40

S2 only has one reference sensor and I seem to be registering it since I'm getting the tach twitch upon cranking

Black51

How 'bout the plug wires? Did you check those as well? Sometimes it's the simple things we miss, well, on our cars, it's actually quite often.

PorscheDoc

Unplug and blow out the AFM connection. For some reason with the S2's, I have seen this happen a lot after it rains. Usually unplugging the afm and blowing out the connection and replugging it back in will allow it to start. No idea as to why, as it really doesn't get wet at all up there.

Airflite40

tried the AFM plug trick and it started up... thanks doc... I'm gonna clean all the connectors and hopefully next rain it wont happen

Airflite40

its back again it wont start since it rained on monday all day.

i am not getting spark from the coil. when I hooked up the timing gun I get a spark randomly like when I turn the key to stop cranking i will get a random spark sometimes.

I have checked everything and think I should just replace the damn coil. I also have a new ignition switch on the way.

Mello

On one of my cars I had a problem with a rusted out battery tray. Water from rain or car wash would drip into passenger foot area and make its way onto the computer. No start until it dried out a day later. One time it even cut out while driving after a car wash. Problem was gone after I POR15ed the battery tray.

Mello

I should add that the battery tray hole was on the front side of the battery, making the drip really far forward in the foot well and not very noticeable.

peanut

have you tried the 3xway DME bypass yet ? (Clarks Garage Workshop)
If you use the bypass and it starts it will limit the things that need checking as the bypass bypasses the ECU as well as the DME relay

Both your fuel pump and your coil are contolled by the ECU via the DME relay.

If you don't have a spark the first place to check is at the ignition pack or amplifier. This is where your coil's primary circuit is grounded by a signal from the ECU.

Is the car cranking at 200rpm+ ? it will need to for the ECU to allow ignition and fuel delivery.

Rain induced problems do suggest dodgy electrical connections and possibly earths. Would be worth checking and cleaning MPll and MPlll and engine to firewall earth strap and unplug replug all electrical connectors ie injectors , crank sensor, etc