93 civic only starts with ether and will stay running
 

Hi all and thanks in advance!!
I recently put a new ignition switch in a 93 Honda civic prior to putting it in the car with some jiggling would start and run. Now the ignition switch works great but the car will not start. Although a shot of ether it starts right up and runs fine until the car is shut off again. Then again it will crank but will not start with out some help from a ignitor like ether.
It did have a old security system on it which was removed could this have something to do with it.
So it seems the fuel is shut off until ignition then the car once running runs fine.
Any ideas? Thanks

Re: 93 civic only starts with ether and will stay running
 

I dunno.. Thoughts:

Was this an issue before replacing the switch?

Connect your old switch and see if the problem is still present (just plug it in to test, no need to fully install it)


See if fuse 18 is blown
See that fuse 18 receives power only during cranking

Recheck everything in on and around the old alarm connections, good possibility something was disturbed

main relay/fuel pump output test, does it run the pump during cranking??

Re: 93 civic only starts with ether and will stay running
 

No this was not a problem before.

Yes fuel pump runs when key is turned and after start.

I will run a check on the fuse and check connections. Great idea on plugging in the old switch,

Thanks for the reply

Re: 93 civic only starts with ether and will stay running
 

Does the same thing with old switch, fuse 18 ok only activated when engine cranked. Still looking

It has to be with the fuel or air something is not letting it have fuel for initial start up.

But once started on ether it runs fine is there a control that may do this.

Fuel pump runs before start up etc.

Any Ideas?

Re: 93 civic only starts with ether and will stay running
 

Hmmm. I don't ever get to see cars this old with weird problems first hand...

A scanner that can read live data from the OBD1 ECM would be real handy (3 pin data link connector) right now.

Not having that, you're kinda reduced to trying to measure various sensor values with a voltmeter or plain old SWAG or WAG..

I might check the grounds on the thermostat housing for being clean, corrosion free, and tight..

Engine/chassis/battery grounds for the same.....thinking high resistance (voltage drop) through the ground cables or connections while the starter is cranking might make the ECM go stupid

ECT sensor for the computer

Open up the ECM and look for telltale signs of capacitor leakage onto the printed circuit board (google image search for examples of leaking capacitors)

Re: 93 civic only starts with ether and will stay running
 

Thanks good ideas I didn't think of voltage drop it wouldn't hurt to check these items. Going to start checking the system one piece at a time.
Thanks for the reply