Well been driving the car daily for a several months, this afternoon, it decided to not start. Here are the current symptoms.... Will turn over several times, I get a stumble, then it will not go from there. So I do get an initial attempt to start, but then the care immediately dies. Prior to this, the care would always start on the first try, but if I drove it for a long time, turned it off, it would be difficult to start in the first 5-10 mins Once started, all things seemed to be well in terms of performance. Only other issue I had was when first driving, there is a hesitation. Sometimes I would get a pop and then the power would kick in. so very poor throttle response when cold.

TempII sensor has been replaced recently, and the connections were checked.

lets see what folks think it can be...

 

Assuming we are talking about an 88S4 if you are close to another S4 owner try putting your LH computer in his car and see if the problem migrates.Alternatively get a friend to crank the motor whilst you squat under the fuel tank to see if you can hear the fuel pump running [or not].

 

Mine was failed fuel pressure and regulator valves.
Diagnose by removing the vacuum line from the valve and sniff. If it smell of fuel replace the valve.
Also, you can use a noid light to check that the injectors get current.
Remove a spark plug and check for fouling and spark - by earthing the spark plug against a point like the x-brace bolt and cranking the motor.
Also make sure the fuel pump is pumping. Remove the return line on top of the tank in the hatch area and crank the motor. You can also check flow rate by measuring volume returned over time.
Happy hunting.

 

Yea I do think it is my fuel delivery system. I pulled the fuel pump relay, and saw some copper corrosion on the pins. Cleaned, and the engine did fire up, but I think that was more luck then anything else. I doubt it is that easy of a fix. Will tune all my relays with some deoxit today. I am hoping it is not the LH. I guess only time will tell. Also my fuel dampers are about the last thing I have to replace on the fuel rail, so they are being ordered from Roger. Kind of pricey now. they are getting hard to find.