will an unplugged air temperature sensor and/or coolant temperature sensor keep my honda from starting?

Question

I've done a complete stock engine swap, d16a6 into my 1991 honda crx si, changed the fuel pump, wired so it gets spark. plugged in and grounded everything I can see and the car will crank and not start.

I checked the fuel pressure, it's good; I checked for spark and there's good spark.

My ecu is flashing 6 times (coolant temperature sensor) and then 10 times (air temperature sensor)
I checked and they aren't plugged in and I can't find them!

My question is, with the d16a6 engine will the ECU prevent the car from starting with these sensors unplugged?

If not, any ideas what it could be?

If so, any links or advice on how I could run a bypass because I can't find the male sensors to save my life!

any advice would be greatly appreciated!

Thanks

Answer 1

Both engines in stock form should have the AIT and ECT connectors on the wiring harness and both sensors intact on the engine.



It seems to me that you have losted or the connectors stuck up somewhere during the engine swapping, lot of technicians did the same thing when a connector was in the way when doing engine replacement by move it aside, stuck it up or into a wiring harness and then forget about where it was..



When the ECM did not see the input signals from both the AIT or the ECT, the preset parameters will go into a default mode, meaning cold weather starting or more fuel is going into the engine to help with a cold start situation, so the plugs are probable soaking with fuel and getting flooded?



You'll need to dig out the two connectors from the nearby wiring harness close to the sensors itself.. or you can get the sensors off and go to your local part store and every single one of them should have a catalog for universal connectors, just match it up with the cavities (2, 3 wires) and you'll be set. Make sure you'll have a correct wiring diagram for the vehicle.



After replacing the connectors and if it's still having some kind of performance issue the go ahead and reflash the ECM with the newest software. Most of the repair shop will be able to reflash the ECM for your car nowaday. The dealer is not costing that much more when it come to reflash the ECM. HTH



Editing: For a bad spelling word. Sorry!

Answer 2

Hopefully somebody very conversant with this unit can assist. As far as other engines go being the two sensors this ought not to stop it starting..ecu should go to default mapping and provide own data to enable running even though will be low power etc.

Have we checked timing?

Try petrol head site too, few clever guys there.

Answer 3

No. You need to swap the computer to the one that goes with the new engine. I can't even express how important the computer is. If it's not the right one for the right engine, the engine might as well be siezed, it'll never start

Answer 4

Try this master mechanic.

scottykilmer.com/youtube/automotive.

M y days of cars ended as soon as the OBD1 ended i.e. mechanics and repairs of them by myself.

I'm old school and will work on and give advice on all cars before the 1990 year.