I have a 96 civic with a b18b, when the engine is not up to operating temp. the car misses or sputters, but as soon as the temp gauge is exactly halfway it runs fine. I cant figure it out, it does this everytime i drive. The only code its throwing is code 12? Im using a jumper harness and a manual pr4? Is there anything i can do, im extremly confused why it will run like **** when the engines cold then perfect when its warm! I already replaced the injectors, fuel pressure regulator, MAP sensor, TPS, IACV, plugs, wires, cap and rotor. It makes no sense, and no one on this site has any ideas!

 

You have a bad EGR valve. Pretty straight forward fix.

Heres one for sale. Send him a PM.

 

haha thats funny! Theres no EGR valve on my car! The motor is from a manual car, which dont have EGR valve. I know what they look like, and it doesnt have one! Thats why i said "no one knows the answer"

 

bump

 

Maybe an auto ecu? I have no idea, sounds really f-ed up. Go to a mechanic and see if he'll get rid of the code for you. Does this affect your performance?

 

When engines are cold, they tend to run a little rich. Engines then start to lean out while reaching operating temperatures. Sometimes, this can cause fouling of the spark plugs.

Edit: Try looking into that situation. And get the description of that code. It will most likely help you out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EM1_ChRiS &raquo;</TD></TR><TR><TD CLASS="quote">When engines are cold, they tend to run a little rich. Engines then start to lean out while reaching operating temperatures. Sometimes, this can cause fouling of the spark plugs.

Edit: Try looking into that situation. And get the the desciption of that code. It will most likely help you out.</TD></TR></TABLE>

Its an EGR valve. These dont come on manual cars, only autos. Thats why he named this thread "No one knows the answer?", because it doesnt make sense.

 

So code 12 is an EGR valve code?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EX-T &raquo;</TD></TR><TR><TD CLASS="quote">So code 12 is an EGR valve code?</TD></TR></TABLE>

1 O2A - Oxygen sensor #1
2 O2B - Oxygen sensor #2
3 MAP - manifold absolute pressure sensor
4 CKP - crank position sensor
5 MAP - manifold absolute pressure sensor
6 ECT - water temperature sensor
7 TPS - throttle position sensor
8 TDC - top dead centre sensor
9 CYP - cylinder sensor
10 IAT - intake air temperature sensor
12 EGR - exhaust gas recirculation lift valve
13 BARO - atmospheric pressure sensor
14 IAC (EACV) - idle air control valve
15 Ignition output signal
16 Fuel injectors
17 VSS - speed sensor
19 Automatic transmission lockup control valve
20 Electrical load detector
21 VTEC spool solenoid valve
22 VTEC pressure valve
23 Knock sensor
30 Automatic transmission A signal
31 Automatic transmission B signal
36 traction control found on JDM ecu's
41 Primary oxygen sensor heater
43 Fuel supply system
45 Fuel system too rich or lean
48 LAF - lean air fuel sensor
54 CKF - crank fluctuation sensor
58 TDC sensor #2
61 Primary oxygen sensor
63 Secondary oxygen sensor circuit
65 Secondary oxygen sensor heater wire (black wires)
67 Cat Converter
71 random misfire cylinder 1
72 random misfire cylinder 2
73 random misfire cylinder 3
74 random misfire cylinder 4
80 EGR Valve/Line
86 ECT sensor - Cooling System
91 Fuel Tank pressure sensor
92 EVAP Solenoid/Valve/Vacuum Lines

 

thanks for tryong to help guys but, im still confused?
When i clear the code it will come back within like 15 minutes of driving.
Yes, it affects perfomance, i guess, bc when im driving it feels like it looses a little power usually around 4000 rpm. It just feels like its being bogged down a little bit. Bad ignitor maybe?

 

what year is the pr4 ecu that you are running??

 

Im not sure what year the ecu is, its obd1

 

just try to swap ecus and see if it makes a difference.. ! it may be a problem with the ecu... its worth a try

 

I could try that, it just doesnt make sense that it runs like complete ****, until the engine fully warms up. Its really hard to drive it when its cold, just sputters and misses.

 

I know its throwing the wrong code for this, but maybe your coolant temp sensor is out of range. Maybe when its cold, it senses WAY too motherfreaking cold, and it puts the car's short term fuel trim way out of wack. It might be running super way too rich when the car is cold....but when it warms up, maybe the coolant temp sensor is still reading too cold, but it's got a reading warm enough for it to operate relatively smooth. Like for example, at cold start up, the coolant temp sensor is outputting FULL cold like -40degrees. Then at halfway, it's telling the ECU something like 30 degrees ...still too cold, but enough for it to run smoothly.

This obviously has something to do with cold start up. The EGR valve would have been valid...except for you said you dont have one. How high is your fuel pressure set? I think stock is like 38 or so. I know you said you got a new FPR, but maybe the fuel pump isnt putting out enough or the fuel filter is clogged and the problem is that when the engine is in open loop and it wants to run rich, the fuel pump/filter cant keep up.

Try swapping jumper harnesses....sometimes there is an erroneous connection (which would explain throwing a code for a sensor you dont have).

 

After running through 15 different things it could be my mind kept comming back to your CEL12... that has to be it.
Is the ECU chipped or stock?

Simply put, if the ECU is throwing CEL 12 that means it expects to see the EGR and it doesn't. Simple fix, all though not what you want to hear. Replace the ECU.
All though you should be able to chip the ECU and disable the EGR, but I'm not sure how to do it.

Techno-babble...
Logically the P30-203 code that Crome is based around should work fine with the B18B maps in it. (P30-203 code does not use the EGR) All though I don't know if the EGR is hardware based or code based.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">After running through 15 different things it could be my mind kept comming back to your CEL12... that has to be it.
Is the ECU chipped or stock?

Simply put, if the ECU is throwing CEL 12 that means it expects to see the EGR and it doesn't. Simple fix, all though not what you want to hear. Replace the ECU.
All though you should be able to chip the ECU and disable the EGR, but I'm not sure how to do it.

Techno-babble...
Logically the P30-203 code that Crome is based around should work fine with the B18B maps in it. (P30-203 code does not use the EGR) All though I don't know if the EGR is hardware based or code based.</TD></TR></TABLE>

You can disable the ECU's ability to look for the EGR valve w/ Crome? How?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate &raquo;</TD></TR><TR><TD CLASS="quote">

You can disable the ECU's ability to look for the EGR valve w/ Crome? How?</TD></TR></TABLE>

*cough* thread jack *cough*

 

small thread jack.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate &raquo;</TD></TR><TR><TD CLASS="quote">You can disable the ECU's ability to look for the EGR valve w/ Crome? How?</TD></TR></TABLE>
If I'm right it's more of a code thing. If the code is not looking for an EGR, it doesn't set the CEL. But again "...I don't know if the EGR is hardware based or code based."
If it's hardware based then you're screwed. If it's code based then chipping the the answer.

OP: if your ECU is stock (manual trans PR4) and it's throwing 12 (and not 10 & 2), then there is a problem with it and it should be replaced. If it's chipped then it's a different story.

 

how about the O2 sensor...? you try to test and or replace it...? other than that it sounds like a problem when the ECU is in closed loop... it then goes into open loop when the car gets to normal opp temp.

 

Yea, its a stock pr4, its definatly a manual pr4 bc my one friend that chips ecu's took it apart and verified that. The o2 sensor is new and works fine, i guess ill just get aother ecu.

 

what are the digits after the PR4?
I can tell you what vehicles it is off of and should be able to tell from there if they had the EGR.
At least you'll know if the ECU is fried or working properly so you can sell it.

 

pr4-a61

 

there is the problem... it's not a manual trans ECU.

37820-PR4-A61
92 3dr GS/LS/RS (auto trans)
93 3dr GS/LS/RS (auto trans)
92-93 4dr GS/LS/RS (auto trans)

converting it to manual may solve your problem... http://www.pgmfi.org/twiki/bin...anual all though if it wasn't converted all ready you should have a CEL 19 for auto tran solinoid... so umm yah. get a manual trans ECU.

PR4-A02 (90)
PR4-A10 (91)
PR4-A11 (92-93)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMKid71 &raquo;</TD></TR><TR><TD CLASS="quote">how about the O2 sensor...? you try to test and or replace it...? other than that it sounds like a problem when the ECU is in closed loop... it then goes into open loop when the car gets to normal opp temp.</TD></TR></TABLE>

other way around. Open loop when cold. Closed loop when warm. O2 sensor is not read in open loop.