My car is cranking but not starting. It'll start for a second sometimes and then shut off. All the lights are working and the stereo.

I've had this issue in the past where it cranks but won't start. I'll let it sit for a few minutes and it'll start up. (main relay issue)

anyone have any ideas?

i've researched a little...possible so far is fuel filter, fuel pump, alternator, or the main relay issue has gotten worse.

the plugs and plug wires are new.

 

I've just had a similar problem with my Lude, and it turned out to be the fuel pump .

Check for the easy things first. When you turn the key to position 2, you should hear the fuel pump prime for 2 seconds, and also hear the main relay click at the same time. If this isn't happening, get your main relay out & resolder the joints.

If that doesn't work, whip out a sparkplug and check for a spark. If there's nothing, it could be the ignitor or coil, so you may want to swap in a good dizzy.

If you have a good spark, it's likely a fuel issue. Download the workshop manual and read through the fuelling section to get familiar with it. My next check would be to connect a fuel pressure gauge to the fuel rail and check for pressure. If you have no/low pressure, change the filter. If it does not improve, you need to look at the fuel pressure regulator or the fuel pump.

If the pressure is good, but it still won't start, disconnect the electrical harness from the injectors, and bridge one of them with a wire with an LED inline with it. Try turning the car over, and if the LED flashes, it shows your getting the signal through from the ECU.

Check/replace the resistor box for the injectors (if you have a OBD1 4th Gen Prelude), as I've known this to be the cause of these symptoms as well.

If that doesn't work, you could then maybe try swapping out the injectors for a known good set.

 

thanks!

ended up being a fried main relay and a bad fuel filter

 

Just recently i had same prob. Going to check out your suggestions, thanks for the tips. Pumps good and the relay, but been a long time since i changed the filter.