IIRC, if you bridge the two wires for the Temp II you get full cold enrichment and it should start. Don't run it for long like that. It's a get home trick.

 

What is the gap on those plugs, and how old is the distributor cap/ rotor ? If the plugs are wet, starting proceedure is to floor the throttle, even on a fuel injected engine. BTW, the reason I am asking about the cap is that the spark has such high energy that these cars will often keep running long after a tune up is due, then suddenly refuse to work any more. Was it raining ?

 

Sorry this is troubling me here.. Bill - you said the temp ii sensor was on the drivers side of the water bridge? I have an S4 and the temp ii sensor is on the drivers side, but it is a uk car..

Can we clear this up........ On my car it is the sensor with the Blue connector , on the left of the oil filler cap ( yellow cap ) and is a two prong sensor. Is this same sensor you are trying to describe?

 

found this in the archives Temp II is number 2

 

Ok so according to the picture bill was wrong but that is ok I now have a new number 4 sensor and the number 2 seems to work fine...lol. The plugs are new, The wires are new the caps are new and the rotors are not new but in good shape... yes it started to rain a little after it was parked for an hour or so then proceeded to rain very lightly for another hour or two untill I got in and attempted to leave.
Jacob

 

Ooops! Senility setting in progressively. I mis-stated the side. So, then temp sensor II is actually OK? Do BOTH pins test OK to ground? Test each pin separately. Actually, it would be good to remove the plug from the LH and check the resistance across the plug pins 13 and 5. 13 is where the temp 2 signal comes in and 5 is ground. Do this with the sensor plug in to the harness, of course. If this test fails and the sensor is good, there is a harness issue.

Sorry about the wrong side. Temp 2 sensor failure fits the symptoms (overly rich mixture flooding the cylinders and car not starting). The suggestion to bridge the leads to get the car running if an open circuit is found is right as well.

Well, then proceed with the rest of what I mentioned in my first troubleshooting guide.

Your car is the ripe age for an LH brain failure.

 

"IIRC, if you bridge the two wires for the Temp II you get full cold enrichment and it should start. Don't run it for long like that. It's a get home trick." -FlyingDog -

Bridging the temp sensor simulates a hot engine condition & NOT the cold engine
start condition. An open temp sensor causes the LH to default to a slightly rich
condition over the hot temp sensor condition (300-400 ohms). The LH ECM is
not like the old L-Jetronic with goes full rich with an open temp sensor.
Remember, the temp sensor has two sensors; i.e one for the LH & EZK,
both referenced to ground via the case/body of the sensor.

To eliminate the possibility of a rich/flooded engine condition, it's best to remove
the fuel pump relay or disconnect the LH ECM. As mentioned, the plugs need
to be dried as 928s flood easily. With the fuel system removed, use small
amounts of carb cleaner or even smaller amounts of starter fluid to see if the
engine will fire once the possibility of flooding is eliminated.

 

I'll second what Loren said about gas flooding, which you do seem to have. Mark Burlingame's S4 was hell to get started after it was flooded, even after ventilating the cylinders and drying the plugs as best we could. Eventually it fired and eventually was running perfectly. Left open (plugs out) overnight, the cylinders should be dry. If they flood immediately, you have a problem with the LH brain or the temp 2 sensor. This assumes you have effective spark.

I would try a few short blasts of starter fluid as I mentioned before and Loren suggests.

 

I have since left the plugs out overnight and let the car air out. I pulled the fuel pump fuse and havbe since been able to have the car start on starting fluid. but when I put the fuse back in it seems to flood again. I have tested my temp II sensor and it is at about the correct resistance. This leaves me to believe the computer might be shot. Anyone in the Albany NY area that might bewilling to let me test me LH brain in their car? Thanks again for the help
Jacob Duffney

 

Yes, your 89 LH is due. Mine went out 3 years ago. The failure mode is not classic, but unless you have a bunch of leaky injectors, it's real hard to explain sudden flooding otherwise. Did you pull the MAF plug too for good measure?

Maybe best to start a new thread or edit the title of this thread to indicate you need an 87+ 928 in Albany for LH brain test. Starting a new thread is not a good idea but you need you need to draw attention of the Albany crowd.

 

Yes i did pull the MAF to wich proved to provide no help.
Jacob Duffney

 

Bump. I live a little over an hour south of you, near Kingston. I have an 89 S4.

 

I have an '89 S4 90 miles to your east.

 

You can swap your LH into any 928 fropm MY 87 >>> the differences netween them are minor, compared to the gross malfunction you are experiencing....

 

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