Cel Comes On After A Few Minutes

[mikestang63]

re ran the codes. sorry for the mixup



KOEO- 2 codes

14 Two or more successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a possible engine miss or stall.
19 Failure in EEC internal voltage.

KOER codes-

12 Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) - ISC
41 System lean - Fuel control
91 System running lean - Fuel control

cyl balance

9


I took a video with my phone to show the whole process

 

[jcgafford]

re ran the codes. sorry for the mixup



KOEO- 2 codes

14 Two or more successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a possible engine miss or stall.
19 Failure in EEC internal voltage.

KOER codes-

12 Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) - ISC
41 System lean - Fuel control
91 System running lean - Fuel control

cyl balance

9


I took a video with my phone to show the whole process but can't figure out a way to upload the darn thing.

i would guess 14 and 19 might cause the light while driving. its all about fixing them one at a time now.

 

[jcgafford]

Taking off all your smog equipment will only cause a code.

EDIT: actually, it'll cause multiple codes and make the CEL come on.

i agree. but if it is something you want to do you should wait until you have fixed everything else first.

 

[jcgafford]

re ran the codes. sorry for the mixup



KOEO- 2 codes

14 Two or more successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a possible engine miss or stall.
19 Failure in EEC internal voltage.

KOER codes-

12 Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) - ISC
41 System lean - Fuel control
91 System running lean - Fuel control

cyl balance

9


I took a video with my phone to show the whole process

you don't even want to know how many times i sat in mine and watched that same thing over and over.... anyhow unhook the negative battery cable and leave it sit for 10 minutes with the headlight switch on. turn the headlights off then rehook the cable. run the tests again to ensure a current reading and not some saved old codes. you get the same thing thne it is time to start trouble shooting the codes. you counted the flashes correctly by the way.

 

[jcgafford]

Well, I can hear the darn smog pump bearings - like a grinding noise and I bet that is throwing off the CEL- so I either replace it or remove it. I've owned 3 fox body mustangs and none of them had the smog pump. We don't have smog checks here in FL. Can't really remember seeing one with the pump still on it. lol

fyi my smog pump didnt put out any air. after posting questions about it i finally got under the car with a compressor and found the two or three small holes on the back of the pump itself. unhooked all tubes from the pump and gave it hell with the compressor. crap came out everywhere. when i restarted the car it sounded bad then cleared up. i blew it out one more time and it has worked perfect since. try it before you buy a new one.

 

[mikestang63]

I am definitely thinking the CEL light and the temp rising are related. Drove the car for 1/2 and it was fine. CEL light came on and within a few minutes the temp went from the a in normal to 1/2 way on the gauge. Turn the car off and then back on and the CEL goes away. This is mostly stop and go in town traveling.

Did some research on codes 41 & 91 and saw some common problems

1. Bad 02 sensors/wiring/grounds
2. low fuel pressure
3. broken MAF wire/ dirty MAF

Wondering if any of the following are the culprits?

1. I recently did reoil the K&N filter. Maybe the MAF got dirty with excessive oil?
2. Just put in a 130 amp 3G alt. I added an additional 4 gauge ground from the back of the a/c p/s bracket to the ground connection below the washer overflow by the battery. This was where many writeups said to add the ground.


Tomorrow morning I will check the following
1. ground strap from the back of the driver head to the firewall
2. orange ground wire for the O2 harness coming off one of the 10 pin connectors to the firewall
3. The O2 harness plug that is just under the MAF right next to the passenger side
4. O2 wires to see if they are broke or burned
5. Pull the K&N off the MAF and see if the screen is clogged or oily

Any other advice?

 

[mikestang63]

Fixed the problem. Brought the car into the shop. He hooked up the scanner and it turns out BOTH O2's sensors were bad. Go figure. Replaced them and all seems good.

 

[jrichker]

Over oiling a K&N flat panel filter will deposit an oil film om the MAF element. While you are at it, clean the MAF element.

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables. Changes in RPM causes the airflow to increase or decrease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

 

[mikestang63]

thanks again. already checked and cleaned the MAF. Also was checked out OK at the shop. Hopefully this fixes the codes. was fine on the way home.

Now I can wait until I score a deal on some used headers, exhaust, intake and TB.