Recently swapped in a B16a into my EG long story short first start up the other week it ran ok no missfire etc but HG was damaged and leaking oil a bit so that was replaced with an oem Honda item.

Now no oil leaks starts and revs fine however there is a missfire on idle and the ecu light is on solid no codes, I've tried both a JDM P30 ecu which I know is good and a known working socketed P28.

Distributor, leads and plugs are all good, only thing is the B16 engine loom had been tucked previously by who I don't know but the earth point by the thermostat is missing again unsure if this has been extended in the tuck or grounded elsewhere now, would the missing earth cause the solid ecu light and missfire?

I'm tempted to use my D16z6 engine loom since thats untouched to see if it makes a difference.

 

Had a 93 del sol whose owner had a wire tuck done to it wires everywhere all different colors and car would not start cel light would not go out after 2-3 seconds and stayed on. I got rid the engine harness that was tucked under the dash(bunch of spagettti wires,different color wires from oem and none labeled) Replaced it using a stock engine harness to make it stock back where it should be in the engine compartment. Had to extend wire some wires, checked still no real change and still would not start. Checked power and grounds at the ecu( I believe they are 6 in total but not sure being a long time-anyway you can find info here on H-T or schematic or both. All check good and then checked input and output voltages on main relay all checked good of course I had unbolted the main relay to check--all good. Tried and it started-only thing I can conclude is that I had poor wire connection on the main relay since the car started and worked finde since then. That ground point on the thermostat housing as you know controls the ecu and very important get that done and ensure that you have continuity from it to the ecu.

 

Just a quick update.
Tucked loom swapped out for the Z6 one everything plugged in as it should all 3 earth points are on and fine.
The car still wouldn't start and had no spark so changed the ignition amplifier in the distributor, it was then we noticed the tip of the coil with the little spring on had snapped off, changed that too and the car now starts and runs fine.
No more missfire, idles fine and revs up nicely. However the ecu light is still on solid with no ecu codes when the plugs are bridged.
We have tried a JDM P30 manual ecu, a JDM P30 Manual converted auto ecu and a socketed P28 all the same the only difference is for some reason on the P28 idle is a bit lower.
Also checked the main ecu relay by the bonnet pull that is also ok clicks when it should.

 

This is normal. Unbridge the service connector and the CEL should turn off.

 

Hello

checked the plugs where not bridged and tried again but still have a solid CEL have tried those 3 ecus and even gone as far as burning a new standard map to try across the 3 but no change.

Seems to idle a bit lower on the P28 but bit stumped now, would the lambda sensor not being seated all the way cause the cel? I would of thought that would flash a CEL up when you checked it