Code 8

SPOOLIN · Post by **SPOOLIN** » Sun Mar 14, 2010 9:02 pm

OK, the only thing different is a new engine harness...going through a mil spec connector but please read, i seriously doubt its that. I have tried 2 other distributors and it still pops up code 8, i can clear the code and crank the car and the code NEVER comes back until after the engine is not running but the key is on, it only happens on key on engine off. I have ohm'd out the sensor at the dizzy plug and the ECU plug, i get the same readings (370ish ohms), i have checked continuity and no wires are shorting to ground and it checks all the way back to the dizzy plug from the ecu.WTF?

fly_n · Post by **fly_n** » Sun Mar 14, 2010 10:08 pm

Whether its mil-spec or girlguide-spec a connector is only as good as its installer...

Is this a custom harness or a new stock harness?
If its custom,was the standard shielding type setup on the dizzy sensors retained in some form?

Its hard to look past wiring issues when this sort of thing never happens with stock wiring & 99% of these types of problems are wiring related.

Do u have any aftermarket electricals in the car like ignition gear ,etc?

SPOOLIN · Post by **SPOOLIN** » Mon Mar 15, 2010 5:40 am

Its custom, i have no idea what type wire was used i know its a high quality wire because its strong as hell very hard to strip. I have aftermarket ignition but thats wired seperately from everything else. The code only throws when the key is on and the engine is off!

SPOOLIN · Post by **SPOOLIN** » Mon Mar 15, 2010 7:57 am

i just checked and all of the wire is shielded for the whole harness.

Post by **Spunkster** » Mon Mar 15, 2010 9:51 am

It sounds like your harness is powering the ECU at all times and is triggering the code because it thinks it should be running.

SPOOLIN · Post by **SPOOLIN** » Mon Mar 15, 2010 11:13 am

Interesting! The car runs fine, but thats an interesting point.

Is the ECU not supposed to get power at all time with key on engine off though?? I mean you get check engine lights in the same position on any other car?

Do you have any way for me to test that?

Post by **Spunkster** » Mon Mar 15, 2010 11:51 am

compare your harness to the wiring digram in the Helms manual.

SPOOLIN · Post by **SPOOLIN** » Wed Mar 17, 2010 6:39 pm

im going to do some work with it tomorrow. Heres a note. When i first started trying to get the car to run, i never had this problem, and i worked with it for 20 minutes playing with stuff once i got it running and such. Its when my tuner made his ma and tuned it that the problem started. Im not saying he created the problem himself but maybe some weird glitch could be causing it with the map....is it possible for a corrupt map to randomly throw a cel for no reason and only when the car is sitting with the key on and not running. Just wondering if its possible, not if its ever happened before. Im going to load a virgin map into the ECU tomorrow to see what happens. I never thought to try it. Im also taking a spare s300 to see if it does it as well.

SPOOLIN · Post by **SPOOLIN** » Thu Mar 18, 2010 9:06 pm

well reloading the map and trying a new s300 ecu didnt change anything.

lol, hondata can you just add a check box to ignore this error for me?

Post by **Hondata** » Fri Mar 19, 2010 7:40 am

Take a marker, draw a square on your head and put a check mark in it.

The ECU needs a certain number of working sensors to run the engine. The TDC sensor is one of them, so can't be ignored.

SPOOLIN · Post by **SPOOLIN** » Fri Mar 19, 2010 5:52 pm

lol yeah

Well it will crank while throwing the CEL so apparently its not needed or its working and something is making it think its not working.

fly_n · Post by **fly_n** » Fri Mar 19, 2010 9:59 pm

Go unplug your entire engine harness & just leave 2 wires hooked up.....the main ground strap & starter motor supply.
Now short the starter motor terminals with your pliers or something.....

Did u notice how it still cranks?

fly_n · Post by **fly_n** » Fri Mar 19, 2010 11:39 pm

Just fyi,for your own best interests,u should really learn the difference between the term 'crank' & 'runs',u will probably receive some better targeted advice then....

Post by **Hondata** » Sat Mar 20, 2010 9:10 am

Be civic. First and last warning.

If you either try your ECU in a different vehicle or another ECU in your vehicle then by a process of elimination, you have narrowed it down to the wiring. If you haven't swapped ECUs, do this next.

The distributor outputs a variable voltage based on engine speed. The ECU circuit has a variable threshold for detection of the distributor pulses, so that it can cope with the small signal when cranking (<0.5V) to high rpm (50+V). If you get electrical noise on the distributor wiring with the engine off then the ECU will see a signal, and throw an error code. The stock harness has shielded wires to keep the noise down. Adding another connector into the harness is a bad idea - at the very least, there is the additional resistance of two wire to connector joints, and then connector pins themselves. Also the forementioned shielding must be kept intact.

SPOOLIN · Post by **SPOOLIN** » Mon Mar 22, 2010 6:53 pm

Good point but on a stock obd1 harness, there is a shock tower connector between the ecu and the dizzy. The shock tower connector is nothing special within the pins them selves. All of my wiring is high quality shielded wire, that i know. I have a 61P firewall connector, so as far as # of connectors is concerned, its no different from an obd1 engine harness which im using an obd1 dizzy also. I measured resistance at the ecu plug and the dizzy plug and they were identical. The 61P connector should be more than sufficient in keeping the signals seperate since it has that bulky plastic insert on the female side that surrounds the pins. I guess thats the only thing that could be causing it though really. I guess the last thing ill do it run 2 seperate wires just to see. Maybe i can get the guy who made my harness to isolate the 2 wires away from everything else since its a 61P and im no where near using 61 pins, not even half.