I am trying to troubleshoot my 79 seville without much luck. The car is flooding at start. The only way it will run is WOT or with the tank fuel pump unplugged.
I have changed the fuel pressure regulator and cleaned the injectors. The injectors were fine and fuel pressure is 39psi at idle. The car sat in my garage for 2 years, when I put it away it ran fine. I did not do anything to preserve it. I hate just replacing components and don't know where to go for help.
Automobile(s): '80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
Re: 1979 Seville fuel injection?
Service manual is a must. Quick check without any manual would be to see if BOTH temp sensors measure the same resistance when stone cold. The 2 sensors are exactly the same part number. Make sure you have a good vacuum signal to the ECU under the dash. A vacuum leak will make the thing dump fuel. Get a spare ECU from ebay and keep it with the car in case....
Some people swap the 2 temp sensors while looking for replacements. 1 is much more important than the other but I don't know which.
I doubt the ECU was the problem. Perhaps some of the connections to it. The coolant temp. sensors has a more dramatic effect than the manifold temperature. The Haynes manual is dead wrong about the sensors, as are the companies selling new manifold sensors. The resistance in the sensors goes up with temperature, NOT down like newer
ones. I am testing/ slash installing a coolant and a manifold "guitar pot" that can be tuned in the car. This gives you full control of fuel mixtures as you go. Very simple, cheap, and easy to do.
You are welcome to kick me in the head and correct me if I'm wrong, however, I believe I am accurate.
I found a good used one for the coolant sensor, however a three or four position switch would be as good. One for real cold winter start, two for 30-40 degree start, three for 80 degree, and four for normal operating temp or 180 degrees. each just needs the appropriate resistor wired in. I currently have the manifold air temp on a guitar pot under the hood set around 1000 ohms. I has run very well at that setting. You can richen it or lean it out to find a happy median.