1st) What sensor (circled yellow in pic) is this on my gsr intake manifold and do i need this hooked up for obd-1 motor in 94 civic dx?



2nd) My car backfires in betweens shifts and on deccelleration. What could be the causes of this?

 

it appears to have a vacuum line coming off the back. i think its your map sensor. someone please feel free to correct me if i'm wrong, but i'm pretty sure thats what it is. i dont think your map is located on the firewall. i've never owned a GSR so i'm not 100% positive of the engine bay layout off the top of my head, but like i said, i'm pretty sure thats what it is. and YES you must use the map (manifold absolute pressure) sensor on your car.

 

evap solenoid. Dont need it unless your worried about smog.

 

ok cool...cause it does have a unused vacuum on it and i do have a surging problem. What about the backfiring?

 

corrected^. thanks cuz i wasnt for sure and i didnt wanna give him misinformation.

 

bump for the 2nd question

 

Just plug the port on the manifold and your good to go.

 

Well, no one is taking on the 2nd question, so I will. The cause of backfiring is un burned fuel getting into your exhaust and exploding when it meets any combustion from your cylinders. The unburned fuel can be caused by many things. Bad plugs, wires or coil reulting in a spark too weak to burn all of the fuel, poor igintion timing, valvetrain problems, or an air/fuel mixture that is too rich. Every one of these conditions is equally likely to cause back firing so you'll need to look into all of them. Here's what to do...

1. Ground your plugs while they are still hooked to the wires (somewhere you can see them) and check the strength or even existence of your spark.

2. Advance your ignition timing a couple of degrees and see if that fixes your problem.

3. Check your cam timing and make sure it's where it should be

4. Make note of whether or not your gas mileage has become lower since the backfiring began. Or just invest in an air/fuel ratio gauge.