eumoria

I have a CRX but I posted in this section because the motor is a D16Z6.

My check engine light came on the other day so I flipped the switch I made for the checker and it blinked;

1 long, 1 long, 1 short

I looked in the service manual and although it didn't say anything about Long/Short blinking it did say that 3 blinks means MAP sensor.

So what my question is: What does the MAP Sensor do and why would I get the CEL 1 time then never again (besides an electrical/wiring problem)

Also my engine hunts (surges idle) when it's cold but when it gets warm enough for the idle to drop below 1000RPM it stops. Would that have anything to do with the MAP Sensor? I assumed it was the CACV (cold air idle control valve) and haven't got around to fixing it because it didn't seem like a big deal.

The CEL does not appear when hunting. It came on at normal operating temperature in 35 degree weather w/o the heat on in stop and go traffic. I don't remember what exactly I was doing when it happened (if I was idle or accel/decel)

For people who hate reading:
What's a MAP Sensor?
Can it cause idle surging (hunting idle) when cold?
If it only came on once and not again should I be worried?

Thanks for any help!!

slambedcivic

your surging idle is cause from a faulty Fast Idle Thermo Valve (FITV). its located directly beneath your throttle body. you should take it off (3 10mm bolts and 2 hoses if remember correctly) remove the 2 phillips head screws on the end or 8mm bolts. however you what to get it off. and screw the big plastic plunger all of the way back in. that should cure your idle surging.

as for your map sensor, if it was a one time thing, ide just let it slide. usually if there is a problem the CEL will not go away

slambedcivic

sorry forgot to answer the MAP question.

Your MAP sensor senses how dense the air is that going to be going into your engine. MAP stands for Manifold Absolute Pressure.

eumoria

Thank you so much for that information. I should've remembered that... I fixed a surging idle on my brother's B16A by screwing back down that plunger I completely forgot about that on the mpfi motors.

Thanks a million!

IIXtremeHansen

1 Long, 1 Long, 1 short
isnt that 21? Vtec solenoid?

redcivic44

Yea just cause it blinks 3 times doesnt mean thats the code. The first long blinks is the 1st digit and the short blinks is the 2nd digit. And its a Vtec solinoid. Check the ground on it, and your oil. If you have no oil pressure it wont work and throw a code

eumoria

I didn't know how to count that... I come from non-OBD world.

Code 21 blinks? VTEC solenoid?? Uh oh.

Well it hasn't happened since so I guess it's not an issue. The engine must have overheated when the previous owner had it because I tried to unbolt the FITV like slambedcivic said to and I sheered off the bolt. This also happened when I tried to remove the water temp radiator fan switch... snapped it clean off.

This head is probably warped and fubar and I plan to replace the motor eventally anyway. I don't trust whoever put this motor in because it's been a disaster from the top to the bottom.

Thanks for all the help guys.

slambedcivic

those bolts break often because they rarely come off.

FYI, when you check your CEL one long blink = 10, and one single blink = 1, then you add them together. thats the way i was taught