hey guys, maybe someone here might know this problem that I'm having. I have a 89 crx and I just drop a SOHC v-techd16 in my car. My question is why is that when I unplug my map sensor my car dies out?

 

why are you unplugging it anyway?

 

I wanted to see if my map sensor is defective or not. right now my cell is showing 3 and that's the map sensor

 

The cars computer relies on a few critical sensors to run the engine, the most important are the Throttle Position Sensor and Manifold Absolute Pressure sensor. Without a MAP sensor, the most Speed-Density fuel injection cars will have no idea how much air is going into the engine and they will stop running.

Some cars have emergency limp-mode fuel maps to only run off one sensor, but I don't think Hondas have this back-up.

This is similar to unplugging the Mass Airflow Sensor or Air Flow Meter on a metered airflow fuel injection system. Mitsubishis have a backup system that will keep them running (poorly) and older Mazdas don't (and will shut off.)

 

My car had a limp mode in it. My TPS sensor could be plugged in or not and it ran the same.

 

THe only difference is that when it wasn't plugged in, it would give it a little more fuel than it needed.

 

That makes me wonder then, how would Honda speed-density cars run with no TPS? They have no other sensors to judge the airflow of the engine, other then to read the tach signal along with pressure... Come to think of it, those two signals could probably work.

Redline: nice F'ed link, I had to click to see why you cross-bred a Toyota engine code with a Nissan product.

 

Your honda doesnt have a "Limp mode", it will run just fine without the tps but it has to have the MAP sensor. The computer uses the map sensor to determine the load of the engine which it then uses to determine injector pulse width. These are extremely basic engines! Were talking about 15 year old technology!!

 

So if it doesn't NEED the TPS then what does it use it for?

 

The more inputs the computer gets, the better it can judge how much fuel the car needs. I can promise you the car will fail emissions tests without a TPS, because without it the car has to guess what the throttle position is based on other sensors.

If the car shipped with no TPS, it wouldn't be US legal and it would suck down more gas.