my car will not start

Ok This is my problem. I have a 92 accord coupe. I just got it. It had
a problem starting. One guy said I needed to put a new computer in it.
Done that and the car would start fine. I started it up like 5 times
in 3 or 4 days. and only drove it a round the block like twice. I was
sure that it was fixed, but today it was right back doing the same
thing. It just turns over. Can any one help me. I need to get the car
fixed, so I’ll have wheels till I get one of my crxs runing again.

Thanks.

 

Hi

It could be many things, so start with the basics:

Check to see if you hear the gas pump buzz when you first turn on the key
where all the lights are on, but the car is not started. You'll hear a
slight buzz coming from what appear to be the trunk and after two seconds a
click from under your dash. Not hearing the buzz and/or the click might
suggest the fuel pump or main relay -- especially the relay is notorious for
messing up like that.
Also, usually when you start the car (without it actually starting) you will
smell the gas under the hood if gas is getting to the engine.

If you know you are getting gas, check for spark. If you don't know how to
check, get a simple tool from Autozone/Pepboys to plug instead of one
sparkplug and start the car to observe the spark while someone starts the
car.

Knowing these basics will help you find the problem - just post your result
back here. Plenty of guys (gals too, come to think of it know where to
take it from there and suggest other things to try.

Regards,
Remco

http://www.AutoForumz.com/eform.php?p=361981

 

====================

If it doesn't run the fuel pump when you (quietly) switch the key to
position II, smack the dash to the left side of the steering wheel. If
you hear the pump run for three seconds, try starting it. It will start.

Search this group for the many helpful descriptions about 'Main Relay'
troubles.

'Curly'

 

1) Got fuel? 2) Got spark?

Fried ECU requires investigation then installation. For example, open
diode in main relay can destroy ECU's driver circuit, thus no fuel
days later. Diagnose now, or risk another dead ECU.

 

mmmmm.... an open diode is like a break in the circuit. There would be no
voltage moving across an open. You mean a shorted diode that may hold the
relay in the energized position allowing excessive current flow, or one that
allows voltage to flow in the opposite direction of design basically running
negative to positive.

Either way...dead ECU....

 

Uh,diodes are used *across* (in parallel to the coil) relay coils to shunt
the back-EMF;if the diode shorts,the relay is shorted too(and inop),if the
diode opens,then the back-EMF is not shorted and can damage other circuitry
(but the relay still works).

 

ah...parallel to the coil....kind of like a filter. I was not sure the
orientation of the diode in the circuit....I can see it now....makes sense
in this case.

Thanks for the clarification.

Either way.......dead ECU.......

 

Yup. The neat thing that makes a diode work is that the current from the
back-EMF goes in the opposite direction than the current energizing the
coil.So the energizing current is not shunted past the coil,but the back-
EMF is shorted out.