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Random stops & no starts

  #1  
Old 12-04-2013, 05:40 AM
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Default Random stops & no starts

I have a 94 civic DX automatic that will stall completely and not restart.

The car will run fine and then just fail, all lights remain on, just losing ignition or fuel or both.

Afterwards it will sometimes start right up, or sometimes when I turn the key to the on position the fuel pump will not kick in, the engine light will stay on and flicker with a sad random clicking from the solenoid in the shifter.

After some retrying or after waiting a while you can turn the key and hear the fuel pump kick in, and the shifter solenoid doesn't make any noise and the car will start fine.

Does anyone have any ideas what this is caused from???

I have replaced the relay and the fuel pump, almost seems like an electrical short, like the relay is trying to activate the solenoid in the shifter instead of the fuel pump.

Any ideas before I go throwing more money without knowing where to throw it would be greatly appreciated.

Thank you
 
  #2  
Old 12-04-2013, 07:11 AM
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I'd tend to think its the ignition switch. Do the "oil" and "battery" lights also flicker? Also you could be losing power to the whole car due to bad connections of the battery cables or a problem in the main fuse box under the hood next to the battery. Also check the small engine ground wires on the thermostat housing.

The solenoid in the shifter is only connected to the ignition switch and the brake pedal. It doesn't have anything to do with the ECU computer or the engine.
 
  #3  
Old 12-04-2013, 03:01 PM
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Originally Posted by mk378
I'd tend to think its the ignition switch. Do the "oil" and "battery" lights also flicker? Also you could be losing power to the whole car due to bad connections of the battery cables or a problem in the main fuse box under the hood next to the battery. Also check the small engine ground wires on the thermostat housing.

The solenoid in the shifter is only connected to the ignition switch and the brake pedal. It doesn't have anything to do with the ECU computer or the engine.

The other lights didn't flicker, just the solenoid along with the engine light, and when the fuel pump kicks in the solenoid doesn't click and the engine light goes away.
 
  #4  
Old 12-08-2013, 02:31 PM
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Just asking...

Did you check the main relay? Simple check/fix

(Man, I feel that I'm pushing the whole 'main relay' thing like it's crack lately , but it seems to be such a known issue and easy enough to check/fix, it's worth mentioning because even if it's not a problem now, it could be in the future, and you can eliminate it as a problem)

 

Last edited by Jymmm; 12-08-2013 at 02:33 PM.
  #5  
Old 12-09-2013, 04:52 AM
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No, the relay is fine,

Would the fuel pump not kick in if the distributor is failing?
 
  #6  
Old 12-09-2013, 05:15 PM
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Originally Posted by nitro169
Would the fuel pump not kick in if the distributor is failing?

*I* don't know for sure, but...

You could use a test light or meter connected to the fuel pump wiring to see if it's operating when it should be or if it's intermittent.

Use the wiring diagrams for your car to see where to test from, and you might even drive around a bit (if you can) with the test light/meter connected to see if there are any changes while driving.

If you do, be sure to connect your test wiring so that it's secure when driving to prevent any shorts.
 
  #7  
Old 12-10-2013, 07:49 AM
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Bad distributor would cause no spark, but the 2 second fuel pump prime cycle would not be affected. The ECU basically doesn't use any signals from the distributor until the engine is turning.

If you're sure everything is getting power and the main relay is good, this problem could be the ECU itself.
 
  #8  
Old 12-11-2013, 04:04 AM
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Default Ecu

I took apart the ECU and replaced a leaking capacitor, didn't burn the circuit board or anything, everything else looked good, but the car does the same thing...

I have another ECU coming in later this week and I will give it a try.

Are there any other electrical tests I can do to confirm its the ECU?
 
  #9  
Old 12-11-2013, 05:41 AM
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Basically the diagnosis of an intermittent ECU fault is to try to rule out everything else before replacing the ECU.

One more thing you could do, While it is not starting, test all the power and ground wires going to the ECU to confirm that they are indeed powered and grounded respectively.
 
  #10  
Old 12-11-2013, 07:53 AM
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Default Diagram of ECU

Does anyone have a link to what is power/ground on the ecu?
 

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