Thanks for looking. My 92 DX all stock, which I got a about a month ago, only start sometimes. I mean it'll start and run and then shut down a few minutes later and sometimes it won't. I thought it was the main relay, so I bought and installed a new and it still does the same thing. When the ignition is turned on the dash lights up, the CEL stays on and fuel pump does'nt prime but when I jumped the wires at the main relay the pump does run. So I do know the pump is good. Also, I checked the terminals including the ignition termninal at the main relay according to the Helms manual and there're all good and getting power. Now, I'm starting to suspect the ECU cuz like I said earlier the CEL stay on and the pump does'nt prime when the ignition is turned on. Checked for codes but the CEL stays solid when the check connector is jumped. Here's the kicker sometimes it'll start without any problem. All the fuses, cap, rotor, distributor, sparkplugs and wires are next to new. Is there anything else I should look at besides the ECU? Also, does the ECU control the main relay?
Thanks.


Modified by nemesis25 at 6:17 PM 11/12/2008

 

Anyone?

 

when it doesn't start, does it crank?

 

Yes it does crank when it starts and when it doesn't start.

 

Anything else guys?

 

https://honda-tech.com/zero...92010

http://search.yahoo.com/search...UTF-8

If you conclude your ECU is fried (looks likely), then get one at a junkyard for your engine, and make sure there is an exchange policy so if the junkyard one does not owrk, you can trade it for another.

 

Thank you for the link.

 

Sure enuogh the ECU was bad. It started right up after I put in the one I got from the junk yard. Also, just so you guys know the ECU does control the main relay. The only issue though, is my idling is bouncing around when the engine's cold. I don't know if this has anything to do with it but the ECU that was on was a P06-A00 and I could only find a P06-A02 which was intalled. And now the rough idling started. So what do you guys think?
Thank you.


Modified by nemesis25 at 9:54 AM 11/16/2008

 

What is the complete part number on the ECU? E.g. for the 4-door 92 DX, http://www.bkhondaparts.com says the ECU part number is 37820-P06-A01.

Is the ECU now showing any codes?

Assuming the ECU is okay (and it may not be... ), for now for the idle problem, I would start by topping off and properly purging the cooling system of air. Follow the manual's instructions to the letter. This means you may have to wait 40 minutes or more for the radiator fan to come on twice. Certain engine sensors need to be fully immersed in coolant to work properly.

If this does not work, then the next thing I would check is the idle air control valve.

 

^^^^^^ or vacuum leaks, advanced ignition timing, or sas or idle air bypass screw adjustment.....

 

Actually there is'nt any codes. The ECU part number is 37820-P06-A02 which I installed and I removed 37820-P06-A00. I changed the Idle control valve but that did'nt change anything. Also, I changed the FITV. Hopefully that'll fix it but I won't know til tomorrow, when the engine's completely cold. The coolant's level is good and there is'nt any vaccumm leaks.

 

No doubt many of the veterans here know this, but FWIW, http://rywire.com/store/faqdes...24236 suggests the replacement ECU you installed should be fine. The A02 is a later revision for the manual tranny 92-95 Civic DX. I do not know exactly what all a later revision implies.

Not sure you know this, but the coolant level will appear fine even with air in the system. You are a new owner of this used car. It is hard to say exactly what the original owner did to it, so starting as fresh as possible is a good idea when a problem arises. Two cents.

 

I have an ECU from a 95 DX thatll work as long as yours is a 5 speed, I can convert it to an auto if you need me to tho, 50 bucks + shipping and its yours bro. Although Ive learned in previous experiences that putting an auto ECU in a 5 speed hasnt produced any adverse effects to my knowledge, not even a CEL. As far as the idle, does it smooth out once the car warms up? Heres how Ive always set my idle:

-Warm the car up to normal operating temp
-Unplug IACV (its the thing bolted onto the back of your intake manifold behind the throttle body) The car might stall, so just keep a hand close by the TB to keep it alive.
-Using the Idle adjust scew on top of the Throttle body, turn open, or close until the car is idling at about 650-700
-Turn car off, plug IACV back up, reset ecu buy pulling the fuse in the top left corner of the underhood fuseblock, leave it out for about 10 seconds, and reinstall it.
-Now your idle should be around 900-1000, thats the lowest Ive ever been able to get my car, but i also need to replace my Fast Idle Thermo Valve, which can also be your cause of eratic idle.
If your car still surges after this, you MAY need to adjust your IAC. All that is needed is a 4mm allen head socket (use a socket, an allen key makes it a pain in the *** to dial it in just right. Make sure you do all of this with the car at operating temp, as it will greatly change if you do it while cold, and then the engine warms up.
-AND if that didnt work, bleed your coolant, air in the system will cause the IACV and FITV to act REALLY shitty. Hope this helps, PM me with any more questions.

 

Thanks for your imput. I think the erractic idling is gone after I replaced the Fast idle thermo valve. It's finally running good. Thanks again everyone!