92 civic hatch using p28. engine is a 96 fully built turbo gsr.

update 9-8: not the ignitor or coolant temp sensor or the ECU/chip. i have found that as soon as the richening out happens, if i shut the car off and turn it back on while driving, the AFRs return to normal. if the car DIES/STALLS and i restart it, they will remain rich.

my car has been tuned by a reputable local tuner.

situation: car runs with the correct AFR's 85% of the time. doesnt matter how i am driving. However, sometimes my AFR's will drop to 9.9-10.0 and remain there no matter how i drive. after anywhere from 10-60 seconds the AFR's return to normal.

normal idle is a steady 1100rpm. when AFR richens out, idle surges from 500-800rpm.

The car IS actually running rich. the sensor is not giving a false reading.

can some people please point me in the right direction to solving this problem.

thanks in advance, doug

 

type of map sensor?

 

modified honda map sensor.

tuning software is chrome.

 

modified how?

I've seen this issue more than once with Crome, usually rebuilding the bin from base takes care of it.

 

my tuner sells map sensors that are in a honda case but read up to 30psi. not sure exactly whats done to them but he sells them alot.

 

bump

 

bump. still cant figure this out.

 

my tuner is also completely stumped.

 

bump...what more info do u guys need? ask some questions.

 

bump

 

leaking/sticking injector?

 

I am also going to go with the map sensor. I bought one of those diy kits to save some money and it worked great for a month or so then I was getting the same issue you are having. After a few days I could no longer drive it. I ordered a hondata map sensor it fix it on the spot. Borrow someone's map sensor or put yours on their car and get back to us.

 

sounds like a plan. any imput helps guys.

thanks champ

 

ditto. this has happened to me twice over the past 3 or 4 years. in both instances it was my gm 3 bar map sensor that went bad.

 

my friend had a gm 3bar map sensor do the same thing....

 

HERE WE GO:

MAP sensor is not the problem HOWEVER I DID FIND....

with the car off i have 12.6V at battery.
with car running normally i have 14.4V at the battery.
with the car running like **** (very rich AFR) I HAVE NO VOLTAGE AT THE BATTERY.

is this a faulty alternator or voltage 'regulator' i believe its called?

LMK please

 

sounds like you defiantly have a electrical problem. check and clean all your grounds first...if that does not help then replace the alternator.

allot of tunes rely on proper battery voltage to supply the right amount of fuel....it should be tuned into the map...

 

yeah as soon as i saw that the first thing that popped in my head was the engine was running on 14+ volts and was going to throw off the scales to sensors and supply too much power to the fuel pump causing a rich condition.

but before i found this out i replaced/cleaned the grounds and it made no difference. so i need an alternator most likey? is advance auto still an OK place to have test it?

 

well while the car is running it is supposed to have 14+volts.. thats how the alternator works, it has to supply more power then the battery requires in order to supply power to the entire car's electrical system while its in use and to recharge the battery. However the car reading 0 volts while you are having this issue with running too rich doesnt sound right.. What are you using to read voltage? and if you have a voltage gauge where is the gauge tied in? its kind of strange that you would have 0 volts even though the battery is still hooked up. you should get a minimum of 12 volts (or 11.something at the least)

 

there is no way the car made 0 volts while still running. i had an alternator die on me once while i happened to have the laptop hooked up. the car started to run like crap with voltage in the mid 12s and wasnt really driveable by 11.8 or or so volts.

i think you should be in the mid 14's above like 2500 or 3000 rpms.

alternator seems the likely issue, or at least something in the wiring leading to and from it...

 

im using a fluke 87. i know it seems very weird that i would have a 0V reading but i check again and again because it didnt make since. as soon as the ingition was cycled and the car began to run normal again the voltage was back to 14.4

 

I have the same problem and cant figure out what the issue is. It seems to be an electrical issue to me as well. I am not sure if the altenator is the problem because the battery is still charging.