[JK McDonald]

Hey Yoni - Don't forget that during the initial start your engine is cold and the cold start thermistor switch (in the front water jacket) is probably energizing your cold start injector as the starter turns. This solenoid style injector throws any remaining residual fuel pressure left in your system into the intake manifold (like a bucket with a hole in the bottom) and helps to start any engine as long as there is at least some residual pressure remaining. If your car does not start after the 1st cold engine attempt - all of the residual pressure may have been used up. Any additional attempt has no residual fuel available. Once the engine has warmed up - the cold start injector is no longer in the start mix.

After driving around a while - everything will be fine until you park the car. Then if you start it back up within a relatively short period of time, your residual pressure may not have bled down very much. But if you have shut down the car for too long, the residual pressure may now be too low for an easy start.

At this point the engine is probably too warm for the cold start circuit to activate and since the 8 primary intake injectors only open by pressure, they wont even begin firing until about 30 Psi is in the lines. The fuel pump has an air flow safety switch in the mixture control unit which doesn’t allow the fuel pump to run until air is being drawn into the intake from piston movement. Naturally - if the residual fuel pressure is too low - it takes 10 - 15 seconds of starter operation to bring the fuel pressure up high enough to begin opening the main 8 intake injectors.

All the above information is assuming that you have tested for a residual pressure issue. Please realize that we are all troubleshooting by guess and by golly using the information provided and there may very well be a different problem you need to chase down ... check Mrmerlin's input.

Hey Landseer - the thermo-switch (cold start thermister switch) may be a good call if the cold start injector is trying to over fuel every start process. Yoni - check to see if 12 volts is being applied to the cold start injector at every attempt to start your car.

Good Luck, Michael