My Model:
1991 FC3S Turbo2
i THINK its made in Germany :P

Car Mods:
- AC removed
- PFC from Japan
- Streetport
- Koyo Rad
-Basemap with alittle tunings when discovered running rich

Cant think of any other mod that might be problem related

The Problem(s):

-Watertemp jumps between -5 and +90 Celcius after a minute of driving and it may change as fast as jumping from minimum too maximum within the second.
-Car starts jumping/coughing/misfiring/detonating
-Car has gotten harder too start now that it has rested a few days (leaky injectors?) but still its not a problem too fire it up, but it DOES start less easy.
- Let me add that this erraticishnishness only occours when i throttle, runs fine on idle.

The Story:

Ive had the car in at a specialist and they werent really sure what the problem was, i picked down the intercooler and some tubing too get to the Watertemp sensor and i notice that it REALLY LOOSE, like im pretty sure it can shake out of its socket at hard driving. I have a replacement tempsensor and that will be my first action next time i grab the wrenches. After driving for just a minute my car starts running erraticly, i changed all spark units like coils and plugs.
The last time i was down in the garage and fired it up and let the clutch go too drive it simply jumps and stops ( as if it was an electrical issue and not mechanical).

Please guys im at my last nerves and im not asking anyone too solve my problem just give me some pointers too how i can start problem searching

 

I'd replace that water thermo first and see what happens. That was my first thought before I got to the line where you mentioned it. That thermo sensor will cause... well alot of what you are describing. Your base maps should be calculating the timing and fuel enrichment from that thermo sensor reading along with the air temp sensor. I don't know anything really about the PFC, but I know enough to know it is rather reliant on that thermo sensor.

 

After removing the dynamo and the intercooler, should i be able too get the sensor changed from there? Cause when i tried last time the back of the sensor hit "something" maybe it was the shortblock wall.

 

You should be able to just remove the alternator to get to it with an open ended wrench.

I need to go outside and pull my car into the garage for some work anyway so let me do that real fast and I'll post back up if I can see anything else that is in the way.

 

Hmmmm, I dont see anything else in the way. Did you unplug the harness attached to it before you tried to remove it?

 

Im not sure i remember if i did, but i will be sure to do tomorrow when i pick it down again

 

So i changed the WaterTemp Sensor and put just a little drop of superglue on the connection so the temp jumping is not a problem anymore, the pfc`s shows a concistent function there. Ive also got rid of the erratic throttle problem...ALMOST!

Its driveable now, usually it would give up as soon as i let the clutch go in gear, now i can accelerate abit. But when i hot 0.18 in pressure on the turbo if doesnt wanna accelerate anymore, i havent checked around which RPM it happens yet but will do tomorrow.

If i give it the floor and rev up too lets say 5000 rpm and let the clutch rip it will accelerate at full capacity with turbo and all....