So my buddy has a 93 civic dx hatch 100% stock automatic.
Originally it would only do it on hot days..
So I have him a couple main relays and that helped him a couple times.
Then I soldered one and that worked
Then we tested the fuel pump and all tests lead to it being the pump, so we replaced it with an autozone pump..
Ran perfect for awhile then started doing the same thing.
It would start fine then anytime he let the car sit for 30-60 mins it wouldn't start sometimes.
So he bought a new relay from Autozone.

replaced main relay
Replaced fuel pump

Now tomorrow I'm gonna try to run some tests on the dizzy
And see if I can narrow it down.
Any ideas of anything else I should look for.
I'm sure the tests won't tell much unless the car isn't starting at the time though right?

 

Yeah, the tests won't tell you anything if you test while the car isn't having problems.

Be sure to double check all of the grounds for the motor.

 

You need to thoroughly clean up all of your electrical grounds until they're shiny. Every part that is related to the ground should be shiny, but DON'T scrape any paint!!! So if you remove a bolt from a ground, the eyelit should be shiny, the bolt threads should be shiny, the underside of the bolt should be shiny, the washer that is attached to the bolt should be shiny on BOTH sides.

What I use to clean up the grounds is an emery board, works splendidly! I'll see if I can find a wiring schematic of all the ground locations for your car.

 

Thanks guys will look at all of that when he arrives in the morning..
Doing his brakes too.

I honestly have no idea what an emery board is
I know there is one from the VC to the headlight area, and one to the thermostat, and one to I believe somewhere near the trans.
Also when the car won't start it does crank..
And if he just keeps trying eventually it starts.. Just like it would with a damn relay.

 

Sounds like the ECU may be bad. Try swapping in a known good one to see whether the problem disappears.

 

Can I try a p28?
And it could be the ecu even though it is randomly?
I suppose If I can't reenact the problem I'll let him borrow my p28 for when it happens to him.
I know it will throw a code for being manual.

 

Yes - for testing purposes.

Absolutely

 

Appreciate it Ron!
I'll also check the grounds.
This will be like the 5th thing I have made him put in his car just in case lol..
He must have like 4 relays, now 2 ecu's
A paperclip check cel's and I put two wires with female plugs in his car just in case he overheated again, on his way home from work or something
(Fan stopped kicking on)

 

Car is still having the same issues. And now
Has died at a stoplight
And also sometimes the car hesitates upon startup and idles rough until it begins to warm up

 

Replaced cap, rotor, and coil. I had a obd2 non vtec dizzy, and used the coil from it (seemed to be same part number)
We will see if he still has the same problems..
He didn't have a 10mm wrench or ratchet to try the p28.
But now the bolts are off for him. And if it happens he can try the ecu.

The coil looked a little bent..
When I tested the coil I got 0.6 between what I believe was A and B terminals
When I attempted to test the secondary winding terminal..
I never once got a reading on my fluke multimeter.
If I read it right you test one of the terminals a or b (one of the screw holes on the coil that I took the wire off?) and the other lead to the coil?
I'm not 100% sure I read the diagram correct. But I never got a reading.
I performed all tests with the key in the off position.