i have a 90 CRX Hf with a B16a swap and its been burning way to much gas, ususally only get 200km to a full tank? clearly something is wrong.
if anyone has any idea what it might be could you help me out!
thanks

 

wow your gas mileage is horrible if that is the case. I had a b16 swap in my HF also, but I didn't have your problem. Have you done maintenance to the motor? Tune up? change the spark plugs, filter, etc. you could have a lot of carbon build up which is destroying your mileage.

 

I agree, do a tune up, if it had never had one, change out sensors that may have gone bad, i.e. o2 sensor, or pcv valve.

 

Now its throwing a code, code-6 coolant temp!? could that have anything to do with it. Ive checked my spark plugs ad they were loose. covered in oil so i swapped them out

 

I would check on the coolant temp sensor for any loose connection or frayed wires. If it doesnt take off the CEL, just replace it. If your spark plugs are getting covered with oil, i would check the valve cover gasket for leaks.

 

If your spark plugs are covered in oil you have bad spark plug tube seals. They come in a kit with the valve cover gasket for ~40 bucks.

The reason you may be using so much gas is if the plugs are covered in white and have build up on them from burning the oil it may not be burning all the gas that is being put into the motor as the spark is not hot enough to burn through the buildup.


Also which ECU are you running?

 

well the check engine light only comes on when it goes into reverse?! and i just put a brand new valve cover gasket on and i went to emissions test it today and it failed and made my crx look like a lifetime investor in smoking. it was horrible. ill checck my spark plugs again

ive double checked everything. with teh excepting on the ffrayed wires.
im running the Pr3 ECU. could that have anything to do with it? i doubt it personally, it is the right ECCU for the motor or am i wrong?

 

Yeah it is the correct ECU. which code are you throwing?

 

code 6, which is the coolant temp?!
im pretty sure.

could that have anything to do with it?

 

It might as if the ECU thinks the car isnt up to temp, it maybe using more gas because the ECU sees that the motor is cold.

Hence cold starts, Idles 1.5k-2K RPM, and then when the car warms up, drops down to the target range of 800rpm.

The Coolant Temperature(TW)Sensor uses a temperature dependant diode(thermistor)to measure differences in the coolant temp. The basic fuel injector duration is read out by the signals sent from this sensor through the ECM/ECU.

In this picture, the black sensor with the gold nut going into the block right under the VTEC solenoid. That's the Coolant Temp Sensor. ~$15 bucks at a local car parts place, I'v had to replace it also personally.

 

thats exactly wwhat happens everytime i start it!

so you think it might be the ECU?!
maybe if i find a new PR3 do you think it could solve the problem?!

 

i had the same problem i changed out the valve cover gaskets replace my fuel filter new temp sensor and put my stock exhaust system back on with a catalytic converter stopped the bad smell and smoking and runs like new now . And i also went to get the redline fuel injector cleaner along with the red line antifreeze solution and i'm also running 10w 30 redline oil .

 

No, change the coolant temp sensor. Thats why you are getting crap for gas milage. The ECU sees that the engine coolant is still cold (caused by the sensor not sending the right info or no info at all) thus it making the car use WAY to much gas because it still thinks the car is cold.

Are the Coolant Temp sensor wires frayed or broken?

 

never mind lol

 

Yeah it is, but im saying if the motor is technically warm, but the Coolant Temp Sensor isn't sending the signal to the ECU to tell the ECU that it's warmed up, thus it's dumping the fuel in the car even when it is warmed up because the ECU still thinks the car is cold because it's not getting the proper feedback from the Temp sensor.

 

what year is your b16a might be the same year as my head on my LS/VTEC

 

yes i checked my manual and you are true about that but the start up issue is perfectly normal .

 

what year is the b16a ?

 

alright i went and checked and i checked the coolant sensor and none of the wires are frayed or broken but im going to buy a new a sensor right now and hopefully thats the problem! thanks and ill let you know how it goes because 200km to a full tank doesnt sit right with me.. haha

 

Mines doin the same thing but it runs like crap in reverse and also throws a code 73. But only in reverse. Any ideas?

 

its a first gen

anddd mine still also bogs in reverse!
disconnect your reverse lights and that should help

 

Ill try that. My coolant temp sensor has frayed wires I need to fix. Did unhooking reverse lights realy help? Did it make check engine light stop coming on in reverse? Thanks for your help.

 

some how it worked for me

next problem... soo after i switched out the sensor my car ran great last night. and towards the end of the night i ws parked and it started over heating?!
so i parked it for the night, this morning when i got up i went to drive it home and my vtec wouldnt kick in!? if anyone has any idea why please help me!

 

your vtec plug is near the thermal sensor plug. did you knock it loose. Before you changed the sensor did you get any temp readout? or do you even have the stoc gauges? if the sensor was out your temp on your dash would not change. mabey it was oveheating the whole time.

 

dahm, thats probably why its running like crap if it was overheating all the time..

1 question: if you buy an autometer Temp guage BUT you dont hook it up to your ECU will it still throw a code, or think its overheating?