Flooded S2

Paulbav · 12-17-2002, 02:16 PM

Elo elo

Been having problems starting my 1990 944 s2 after checking everything looks like fault seems to be over fueling on start up and flooding the engine, if i diss the fule pump and dry the cylinders out it starts ok and runs perfectly untill i try to start it again! its allways taken a few rotations to start but i'm told thats true for all S2's somebody mentioned temp sensors to the ECU could be faulty?. Does anyone have any ideas before the long and exspensive garage trip.

Thanx

Makis · 12-17-2002, 02:31 PM

Yes, I mentioned the temperature sensor in the past, but will start suspecting it only if most convensional culprits are rulled out.
So check condition of the sparks, sparkleads, ignition coil, clean all connectors check battery is in good condition, and check once the engine is started is the engine runnig OK, have you got good power?

gearhead290 · 12-17-2002, 07:39 PM

My n/a did something similar then that when I bought it. It made it so that I got one hell of a deal! My problem was the Fuel Pressure Regulator, it was a cheap fix.

Paulbav · 12-18-2002, 11:32 AM

Thanx

I think that it will be the sensor then as i've checked all the things you suggesed allready and there all fine but when i remove the plugs after attempting to start they are soaked with petrol. Do you know where the sensor is located is it an easy to replace part??

Makis · 12-18-2002, 12:24 PM

Ok, the coolant sensor on the S2 can be found roughly as follows:
Open the bonnet. In front of the engine, top of the engine, to the right of the cylinder head, but just under the head and very close to the bleeding screw for bleeding the coolant air bubbles when replacing coolant. There is a connector attach to it and I think it is green/blue. To test the sensor you will need to measure the impedance of the sensor. It should measure over 2K when cold. Also make sure the sensor terminals are isolated from the ground, i.e. no resistance between any of the terminals and the ground. This is very important because this is how my failed and I had to replace it.

A simple way to test that the sensor is causing your starting problem is to just disconnect it and attempt to start the engine. If the engine starts OK then your sensor is almost certain to be the cause. This is how I was starting my engine before replacing the sensor.

However remember the reason the engine does not start with a faulty sensor is because the ECU thinks the engine is warm when in actual fact the engine is cold. As a result the starting mixture is weak and the engine misses to fire. Persitent misses may cause the engine to eventually flood but I have some doubts. Let us know if this is your problem though.

Paulbav · 12-18-2002, 02:20 PM

Excellent thanx Makis will try it at the weekend and let you know. if all else fails there's allways the RAC to tow me to the gararge Doh!!
fingers crossed eh!

Paulbav · 12-19-2002, 10:40 AM

Hmmmmm

Checked the switch as you suggested but it seems to be ok 3K4 when engine cold and after runing a few minuets it droped to around 2K and progesivley lower!.
I'm stuck now, its definately to much fuel on start up as i've had the plugs out loads of times to check and dry them out. If anyone has any other suggestions they would be greatfully appreciated as i think trying to get it into a garage before Christmas in going to be almost impossible!!

Cheers

Paul

Makis · 12-19-2002, 12:48 PM

Can you also confirm that the switch is isolated from the ground?
I.e. infinite resistance between the ground (engine block) and any of the two switch pins. If so then try to check your ignition circuitry, wiring, connectors again from the ECU -> Ignition Amplifier -> Ignition Coil -> Dizi/Rotor -> Spark Plugs. Try replacing the spark plugs with new ones they are quite cheap. Also check battery condition voltages. If this fails check to see if you have leaky injectors and correct fuel pressure. A blocked exhaust system may also cause starting problems. Does your car run properly after is start? Let us know how you doing?

Paulbav · 12-19-2002, 03:40 PM

It definately runs fine after ignition i have checked the switch to ground and there is no circuit there! and i've had the rac out who confirmed that the injectors and the plugs are preforming ok, all the electrics seem to be fine!. I hope there is an answer for this out there some where!!!!

Paulbav · 12-20-2002, 02:02 PM

I've got it into a local garage should be done by monday i'll keep ya posted cheers for the help though.

Bloody typical though it seemed to start ok again when I went to take it in!!!

Paulbav · 12-25-2002, 09:44 AM

Yippeeeeeee She's fixed it turns out it was the HT leads after all the spark was'nt good enough when the leads were cold. So a quick trip to euro car parts was all that was required thank god merry christmas all.