My car is still running extremely rich after my swap and i have no idea why. I have tested and swapped a ton of stuff with no luck so im wondering what are the common causes of an engine to run rich.

BTW its a 97 B18b1 engine in a 1998 civic coupe running an obd1 P75 ECU.

 

Running rich can be a few things. Bad o2 sensor, bad or missing speed sensor. Wrong ECU. Bad MAP or TPS switch.

Throwing any codes?

 

only code is code 1 but it rarely pops up. The weird thing is ive swapped O2's, checked that the wiring form the ecu goes to the proper pinout on the O2 connector and still havent been able to figure out why i throw an O2 code once in awhile.

I tested the o2 signal wire and when i start the car up it is fine but then when the car warms up at idle the voltage reading just sits there but when i put a load on it the voltage jumps up and down

 

ne ideas?

 

when does it run rich?

where is your fuel pressure at?

 

stock FPR and rail so im assuming its stock. i know it runs rich at idle, not sure about at WOT etc.

 

when the car is warmed up, at idle; whats the voltage reading?

 

for the O2? i think it was like .1xx or something

 

is the OBD1 ECU chipped or stock?

 

.1xx at idle would be around 15.x to 1 AF which is right.
.5 volts would be 14.7 and .9 volts would be around 14

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by non-VTEC &raquo;</TD></TR><TR><TD CLASS="quote">is the OBD1 ECU chipped or stock?</TD></TR></TABLE>

ecu is 100% stock as far as i know (worked perfect in my eg hatch)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">.1xx at idle would be around 15.x to 1 AF which is right.
.5 volts would be 14.7 and .9 volts would be around 14</TD></TR></TABLE>

to be honest i believe it was more in the 0.0xx range when idling but ill have to recheck once i get my alt re-installed. All i know is that on cold idle the car starts up fine but then immediately the idle drops to like 600rpm and the engine shakes. I have adjusted my FITV valve back in so either its completely messed or the problem lies elsewhere.

 

clean the TB; take out the idle screw and clean in there also, finally take out the iacv and clean that biatch too.
reset idle to 600 rpms with the iacv unplugged.

see if that works

 

to clean the TB whats the best way? Also to clean the idle screw part do you have to remove the TB or is it suppose to unscrew completely out? I have cleaned the IACV before and i even swapped in another one thats known to be good and cleaned it aswell with no luck. How can i reset the idle to 600rpms with the IACV unplugged? I thought with the IACV unplugged the engine is suppose to die?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">clean the TB; take out the idle screw and clean in there also, finally take out the iacv and clean that biatch too.
reset idle to 600 rpms with the iacv unplugged.

see if that works</TD></TR></TABLE>

K well I just went out and followed the steps in the manual to reset the idle and here are the things I noticed. When the engine is cold and i try to hold the rpms steady it will go up and then slowly drop down and i have to ad more throttle to compensate and it will go down again. Once its warm the rpms will stay steady with stable throttle. When i disconnected the IAC connector the car would not idle AT all, i adjust the screw from where it was before in and out with no change and even completely in and pretty far out and it would not idle it would just die immediately. After i re-connected it and disconnected the battery for 15 seconds and restarted the car it started idling at 400rpm and then slowly rose to like 600-700rpm and then after about 5-10 seconds and it would drop down just below 400 and then catch itself and it would continue to do this in the same pattern.

any ideas?

 

did you take out the idle screw and cleaned the crap in there?

With the iacv unplugged you should be able to get the car to idle by opening up the tb screw.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">did you take out the idle screw and cleaned the crap in there?

With the iacv unplugged you should be able to get the car to idle by opening up the tb screw.</TD></TR></TABLE>

no i didnt take the idle screw out completely as it was to dark to do that but ill try it tommorow. Do i just unscrew it and spray like TB cleaner or what in there? I had the TB screw unscrewed pretty far and the car would just die when i started it up, if i gave it gas it would stay on but as soon as i let my foot completely off the throttle it would die.

 

TTT

 

Bump

 

Still wondering???