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2000 civic ex, bone stock motor/transmission. The motor was just rebuilt and I just got it back in the car and I have a mystery plug left over and can't figure out where it goes. It's located toward the passenger side back toward the firewall and under the air intake tube. Can someone tell me where this thing goes?
Also, the car cranks but won't start, but I'm reasonably sure that's a timing issue.
Figured out the plug but I still have a no start issue. It cranks but won't start. Thinking about more I'm not so sure it's the timing. I was extremely careful when putting on the timing belt to the point of being OCD about it. Anyone have any thoughts on what it might be?
Based on the location, my first suggestion would be the fan switch on the thermostat housing. However, there are a LOT of two wire round grey plugs on the harness... how about telling us what COLORS the two wires are so we can direct you properly.
Check my previous post. I figured that part out. Now I just have to figure out the no start issue.
You may think you have figured it out but there is a couple of two wire gray plugs that are interchangeable and if they are swapped will burn a component in the ECU.
Common reasons a newly installed engine might not start:
Thermostat ground not connected or loose
Sensors not plugged in, or plugged in wrong (check ALL wire colors, including the 3-pin plugs)
Distributor shaft engaged 180 degrees out of time
Spark plug wires in wrong order
No compression due to improper valve adjustment
Make sure the CEL comes on and goes out and the fuel pump primes when you turn key on and don't crank. Then hook up OBD scanner and confirm there are no codes, investigate any codes found.
All grounds are connected including thermostat. Compression is good. All plugs are connected and in the right spots. I'm checking the timing now. I'll check the distributor as well. I thought the ears (?) that came off of the distributor shaft that go into the end of the cam were different sizes though to keep it from being installed 180 degrees off? Also, CEL does not stay on, main relay clicks, and the fuel pump does prime. I also double checked just to be sure, and there are no codes.
Yellow with a black stripe and the other wire is black.
Are you sure it's not a BLK/BLU wire? Sounds like C138 which is your IAC plug (Intake Air Control Valve). It would look like this.
Like others have said, there are a lot of two wire gray plugs behind the intake manifold that all reach several sensors. It's common to mix them up.
Last edited by CX-Adam; Feb 6, 2017 at 04:17 AM.
Reason: IAC not IAT
There is no factory plug that contains the two wires that you have stated. I think CX-Adam is right about your wire colors... blue with a black trace and yellow with a black trace would be proper colors for the IACV and not the IAT as stated above. IAT is a similar plug with a red/yellow wire and a green/black wire. Check your electrical connections... just because a plug fits doesn't mean it is plugged in at the correct location. Now, also as stated above... you need fuel, air and spark. Check your spark plugs... are they wet ??? If not, you don't have fuel. While that spark plug is out, plug it into the plug wire you removed from and place it near something metal and turn the car over... do you have spark ???
There is no factory plug that contains the two wires that you have stated. I think CX-Adam is right about your wire colors... blue with a black trace and yellow with a black trace would be proper colors for the IACV and not the IAT as stated above. IAT is a similar plug with a red/yellow wire and a green/black wire. Check your electrical connections... just because a plug fits doesn't mean it is plugged in at the correct location. Now, also as stated above... you need fuel, air and spark. Check your spark plugs... are they wet ??? If not, you don't have fuel. While that spark plug is out, plug it into the plug wire you removed from and place it near something metal and turn the car over... do you have spark ???
Good catch. I miss quoted the Helm manual. I fixed my previous post. D'oh.
Originally Posted by 90si-rex
Looking at it again it's blue/black.
As for the no start...yes, I have air, fuel, and spark. Looks like the timing was off. Just corrected that and I'm putting everything back together.
If the plug was placed in the wrong location and the ECU fried a pin, NONE of the sensors affected by it would cause a no start issue.
I know he already solved his issue, but man, you people are the absolute WORST when it comes to helping people out in tech and somebody had to say it.
Actually slomofo, a failed ECT sensor or unplugged/shorted ECT sensor makes it incredibly difficult to start a '90's model Honda engine... and it looks just like the plug that the OP posted in the picture.
Where does this plug go?
