81 fi spider 2000 running rich

[topbuddy]

My FI spider is starting right up and runs normal with a little surging but as soon as the engine warms it starts to run rough and it takes coaching to keep it running. I checked the plugs and they are sooting up so assume it is getting too much fuel. My temp sender is normal and the fcu seems fine as well. What other Fi component could cause this? I have heard that the fuel pressure regulator could do this. Does anyone know just what is required to change that unit. I looked at the parts for sale on IAP and it shows 4 rubber discs so I am confused by this, and just where is the unit mounted on the engine?

[RRoller123]

The temp sender may be ok, but the connector to it is a frequent point of failure. You can measure the resistance back at the ECU, and those readings will include the connector and wiring.

[divace73]

The temp sender may be ok, but the connector to it is a frequent point of failure. You can measure the resistance back at the ECU, and those readings will include the connector and wiring.

I concur with RRoller....

[rlux4]

The fuel pressure regulator is located at the rear of the fuel rail, under the intake manifold. You'll see a vacuum line going to it. Check the vacuum line for cracks. You can check the fuel pressure with a liquid pressure gauge connected to the rubber line going up to the cold start injector (front of intake plenum). Be careful if you do this, the line is under pressure and will spray pretty good when you disconnect it.
The most critical sensor for our system is the coolant temp sensor at the coolant T. If it's not good, or the connection or wires are bad as RRoller123 said, it'll give incorrect ohm reading to the ECU which will result in bad fuel/air ratios.
The values and method for checking this can be found in Brad Artigue's maintenance manual in the FI section. He's made these available to us, free of charge.
http://www.artigue.com/wp-content/uploa ... 124_MM.pdf
Ron

[giuliot60]

I agree with everyone else. My 81 just went through the same thing and it turned out to be the $8 CTS connector. I installed it, cleaned up the plugs, and she's been running like a champ.