mp470 Posted September 11, 2017 Author Share Posted September 11, 2017 First, your engine is turning over. turning over has nothing to do with starting . .other than if it is not turning over it won't start :) This is a common misuse of the tern "turning over'. You engine is spinning, it is turning over . .it's just not starting. You should not be using the gas pedal when starting a fuel injected engine. Typically heat related starting or even running issues, are electronic in nature.Heat causes extra resistance, can make small breaks in wiring grow to larger gaps, etc. When you turn your engine off, it heat soaks, meaning more heat is present to this components than were present when it was running. I would not suggest just buying parts to try, but if you can find a loaner coil, that is where I would start first, it's easy. Next would be the module inside the distributor. Helpful stuff, thanks. I'm thinking electronic as well, just wasn't sure where to begin. Link to comment Share on other sites More sharing options...
LARIAT 85 Posted September 13, 2017 Share Posted September 13, 2017 Yes it's a 1985 EFI. Usually I floor the gas pedal and it starts with a bad struggle after which I have to hold the gas partially down for a minute or two to keep it going otherwise it will stall out. My wife's 2001 Ford Mustang was doing that, and the problem turned out to be a bad idle air control valve. In order to start the engine, I had to give it gas as if it had a carburetor. Link to comment Share on other sites More sharing options...
mp470 Posted September 13, 2017 Author Share Posted September 13, 2017 My wife's 2001 Ford Mustang was doing that, and the problem turned out to be a bad idle air control valve. In order to start the engine, I had to give it gas as if it had a carburetor. Thank you, that actually makes a lot of sense. I will try to simulate it by unplugging the valve. Link to comment Share on other sites More sharing options...
PetesPonies Posted September 13, 2017 Share Posted September 13, 2017 My wife's 2001 Ford Mustang was doing that, and the problem turned out to be a bad idle air control valve. In order to start the engine, I had to give it gas as if it had a carburetor. That is a port fuel injection engine. tThe IAC dithers to allow air in during idle . . when the throttle plate in the TB is totally shut. Link to comment Share on other sites More sharing options...
mp470 Posted September 13, 2017 Author Share Posted September 13, 2017 That is a port fuel injection engine. tThe IAC dithers to allow air in during idle . . when the throttle plate in the TB is totally shut. I knew that too, so I'm a bit red-faced on this one. Of course unplugging that valve recreated the issue exactly. Link to comment Share on other sites More sharing options...
mp470 Posted September 13, 2017 Author Share Posted September 13, 2017 I knew that too, so I'm a bit red-faced on this one. Of course unplugging that valve recreated the issue exactly. Well I'm getting somewhere. Went for a long drive. Ground side lights up very dim on the connection to that valve. Now to find where it grounds. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 13, 2017 Share Posted September 13, 2017 Well I'm getting somewhere. Went for a long drive. Ground side lights up very dim on the connection to that valve. Now to find where it grounds. Here's some info: http://www.garysgaragemahal.com/ground-wires.html Pages 60 and following here - http://www.garysgaragemahal.com/electronic-engine-control.html Link to comment Share on other sites More sharing options...
mp470 Posted September 13, 2017 Author Share Posted September 13, 2017 Here's some info: http://www.garysgaragemahal.com/ground-wires.html Pages 60 and following here - http://www.garysgaragemahal.com/electronic-engine-control.html Thanks Gary, looks like it's ground switched by the ECA. I wonder if it's supposed to light up dim while not in operation. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 13, 2017 Share Posted September 13, 2017 Thanks Gary, looks like it's ground switched by the ECA. I wonder if it's supposed to light up dim while not in operation. Let's make sure my understanding of "lights up dim" is correct. Your trouble light? If so, probably yes. Battery voltage is supplied to the various components and then the computer grounds them when it wants them to activate. That creates a current flow and they do their thing. So if you put a trouble light on the ground, or computer, side of any of the components then you will have voltage when the thing isn't activated. Link to comment Share on other sites More sharing options...
mp470 Posted September 14, 2017 Author Share Posted September 14, 2017 Let's make sure my understanding of "lights up dim" is correct. Your trouble light? If so, probably yes. Battery voltage is supplied to the various components and then the computer grounds them when it wants them to activate. That creates a current flow and they do their thing. So if you put a trouble light on the ground, or computer, side of any of the components then you will have voltage when the thing isn't activated. Basically, it's a LED test light that lights up green for ground (hooked to battery +) and red for power (hooked to battery -). Any other body ground lights up nice and bright green, while this IAC ground is very dim. At least it was after that long drive. Link to comment Share on other sites More sharing options...
Recommended Posts