I did my b swap a little over a month ago and have noticed a HUGE drop in my gas mileage. With my old a6 i was getting arund 30mpg now im getting less than 20. At first i figured it was me driving it hard, so for the last 2 tanks i took it pretty easy. I also have the ls tranny. Anyway my driving didnt change my results im still only getting 18-22 mpg. My question is; what is wrong? The o2 sensor is new. I also know its running rich from the black smoke.

B18a OBD-0 Stock civic ef si harness, Teg injectors.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g-ride-si &raquo;</TD></TR><TR><TD CLASS="quote"> I also know its running rich from the black smoke.</TD></TR></TABLE>

Sounds like you might already know the answer to your question.

Get it tuned, get it running normal (not rich). Check timing, etc.

 

im broke so i cant take it anywhere. ive checked the timing and i have; new plugs, wires, cap, rotor, o2 sensor. What else can i check or do??? what else could make it run rich?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g-ride-si &raquo;</TD></TR><TR><TD CLASS="quote">im broke so i cant take it anywhere. ive checked the timing and i have; new plugs, wires, cap, rotor, o2 sensor. What else can i check or do??? what else could make it run rich?</TD></TR></TABLE>

https://honda-tech.com/zerothread?id=1328359

https://honda-tech.com/zerothread?id=1279228

Some of those threads might help. Who did your B18a swap? Was the MPFI wired correctly? Are the injectors clean? Did the person responsible for the swap install the injector resistor box?

 

I did the swap my civic is an si it was already wired for mpfi. Havent checked injectors.

 

I'm not sure if this would cause it to run rich or not, but also make sure the TPS and MAP sensors are not switched around. They have the same plugs and can often be swapped by accident.

 

hahaha, kinda like the same thing with my b16. Im just waiting for the right time to upgrade to obd-1 and fix it from there.

 

I kinda question my vacuum more than anything. 2moro im gonna check to see what codes im throwing.

 

next time check codes first. The ECU is smart

 

i did check the codes it was a 14 which is the eacv. I took it out and cleaned it with carb cleaner, put it back on no code. That was yesterday, tonight cel came back on. I was changing a motor/tranny in a dakota so i didnt feel like checking the ecu again. Can the eacv make it have bad mileage?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g-ride-si &raquo;</TD></TR><TR><TD CLASS="quote">Can the eacv make it have bad mileage? </TD></TR></TABLE>

I might be wrong, but ANYTHING that affects the amount of air or fuel (or a combination of both) can affect gas mileage.

 

ok so i checked the codes I had a 6,7, and a 14. The 6 was a broken wire on the cts(coolant temp sensor). 7 was the tps seensor and it wasnt plugged in all the way and 14 was eacv which i cleaned and reinstalled. Now i have no cel, hopefully this helps my mpg.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g-ride-si &raquo;</TD></TR><TR><TD CLASS="quote">ok so i checked the codes I had a 6,7, and a 14. The 6 was a broken wire on the cts(coolant temp sensor). 7 was the tps seensor and it wasnt plugged in all the way and 14 was eacv which i cleaned and reinstalled. Now i have no cel, hopefully this helps my mpg.</TD></TR></TABLE>

I think that all of the above would affect your mpg. Return and report

 

The car is def. running a lot cleaner no more black smoke. Cant really tell about the mpg yet, still got about half a tank. I am wondering why the cts would affect the performance? If you know please fill me in. I understand how the tps and eacv would but the coolant temp, the car never overheated it has never even came up halfway.