89 mustang rich condition no codes.

[89FoxBodyStang]

hey guys, finally got my mustang running pretty good. idles nice, everything seems to be working fine, but the exhaust smells terribly like fuel. makes my eyes water. just so you know i have a bbk shorties to a MAC o/r h pipe w/ pro chamber and no cats. im thinking it might be time to replace my 02s but i think it's weird that im not getting codes. you can smell the rich exhaust while driving, and on the freeway it is odd. say im cruising at 80 mph and i turn off the cruise, as the rpms drop you get a smell in the cab with the windows down (kinda reminds me of oil, but unsure of if it's oil/fuel) until you hit the gas again. wonder if im just leaking oil under my valve covers, i think that's what the problem was last time.

and another thing. i bought an adjustable FPR of a store on ebay (lol) and i can smell fuel in the vaccum hose from the FPR to the intake. im thinkin that could be a bad thing. maybe that is contributing to my richness. oh and my #2 injector is making a funny "pss, pss" like hissing noise when the car is running. you can hear it with a stethescope on the rail to that injector. it's got no uniform continuity to it, just random hissing. these are newer bosch 19lb injectors...

 

[jrichker]

Fuel in the vacuum line connected to the fuel pressure regulator is a sign that the regulator is leaking internally. It needs to be repaired or replaced.

No code 11 (two flashes when the computer dumps the codes)? The 11 code is computer passed its internal self test.
If you don't get an 11, you have computer or wiring problems.
Please check and repost.

 

[89FoxBodyStang]

are you talking about a quick 2 blinks when i check codes?

 

[jrichker]

are you talking about a quick 2 blinks when i check codes?

Yes, if you got them, you are in good shape.

 

[89FoxBodyStang]

okay... so that would point to it just being my regulator? what about the noise at one of my injectors? is that normal?

 

[89FoxBodyStang]

i checked the codes and had a few KOEO and KOER codes... a couple of which i know have to do with the thermactor system and charcoal canister which i have removed... i did a voice recording on my phone, but had a bit too much to drink tonight and deleted it off my phone by accident while trying to listen to it... a couple i think popped up with KOEO were 66 and 31. which i think 66 has to do with the neutral safety i dont have hooked up. 31 has to do with PFE or or EVP circuits either below minimum voltage or internally failing. what are these for?

 

[89FoxBodyStang]

now that i look at the list of codes again i think i had a code for something HEGO relative. i think it was code 43, HEGO lean at full throttle. i am not for sure i will check again tomorrow.

 

[jrichker]

okay... so that would point to it just being my regulator? what about the noise at one of my injectors? is that normal?

Injectors may make a clicking noise when running: as long as it isn't overly loud, it is OK.
There definitely should not be any fuel in the vacuum line that connects to the fuel pressure regulator. That points to a leak in the regulator diaphragm. Some fuel pressure regulators are repairable like the Kirban, while others are not. You will have to check with the fuel pressure regulator manufacturer to see if yours is repairable.

 

[89FoxBodyStang]

the Kirban is the model i have. i just put a stock replacement on for now. im saving the kirban and im gonna get a replaceable diaphragm for it later on. with the new replacement on it seems to run a lot smoother. but still smells rich when it goes closed loop.

here's the codes i ended up with

KOEO
85 was the first code, then 1 blink, then these codes followed: 31 63 66 96

KOER
21 94 44 33

cylinder balance test passed. code 90

 

[89FoxBodyStang]

and yes i do have the smog system deleted. the EGR valve is on the car. but i really don't think it's doing anything right now exept keeping the car from having a check engine light when running. i bought new spark plugs, and my friend is selling me a pair of 02's for the car he only ran for 3 months before switching to wideband for 10 bucks.

 

[jrichker]

Testing the O2 sensors 87-93 5.0 Mustangs
Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear.

87-90 5.0 Mustangs:
Computer pin 43 Dark blue/Lt green – LH O2 sensor
Computer pin 29 Dark Green/Pink – RH O2 sensor
The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter. The O2 sensor voltage should switch between .2-.9 volt at idle.

91-93 5.0 Mustangs:
Computer pin 43 Red/Black – LH O2 sensor
Computer pin 29 Gray/Lt blue – RH O2 sensor
The computer pins are 29 (LH O2 with a Gray/Lt blue wire) and 43 (RH O2 with a Red/Black wire). Use the ground next to the computer to ground the voltmeter. The O2 sensor voltage should switch between .2-.9 volt at idle.


Testing the O2 sensors 94-95 5.0 Mustangs
Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a red/black wire) and 27 (RH O2 with a gray/lt blue wire). Use pin 32 (gray/red wire) to ground the voltmeter. The O2 sensor voltage should switch between .2-.9 volt at idle.


Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter. Do not attempt to measure the resistance of the O2 sensors, it may damage them.

Testing the O2 sensor wiring harness
Most of the common multimeters have a resistance scale. Be sure the O2 sensors are disconnected and measure the resistance from the O2 sensor body harness to the pins on the computer. Using the Low Ohms range (usually 200 Ohms) you should see less than 1.5 Ohms.

87-90 5.0 Mustangs:
Computer pin 43 Dark blue/Lt green – LH O2 sensor
Computer pin 29 Dark Green/Pink – RH O2 sensor
Disconnect the connector from the O2 sensor and measure the resistance:
From the Dark blue/Lt green wire in the LH O2 sensor harness and the Dark blue/Lt green wire on the computer pin 43
From the Dark Green/Pink wire on the RH Os sensor harness and the Dark Green/Pink wire on the computer pin 43

91-93 5.0 Mustangs:
Computer pin 43 Red/Black – LH O2 sensor
Computer pin 29 Gray/Lt blue – RH O2 sensor
Disconnect the connector from the O2 sensor and measure the resistance:
From the Red/Black wire in the LH O2 sensor harness and the Red/Black wire on the computer pin 43
From the Dark Green/Pink Gray/Lt blue wire on the RH Os sensor harness and the Gray/Lt blue wire on the computer pin 29

94-95 5.0 Mustangs:
Computer pin 29 Red/Black – LH O2 sensor
Computer pin 27 Gray/Lt blue – RH O2 sensor
From the Red/Black wire in the LH O2 sensor harness and the Red/Black wire on the computer pin 29
From the Dark Green/Pink Gray/Lt blue wire on the RH Os sensor harness and the Gray/Lt blue wire on the computer pin 27

There is a connector between the body harness and the O2 sensor harness. Make sure the connectors are mated together, the contacts and wiring are not damaged and the contacts are clean and not coated with oil.

The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts

Make sure you have the proper 3 wire O2 sensors. Only the 4 cylinder cars used a 4 wire sensor, which is not compatible with the V8 wiring harness.

Replace the O2 sensors in pairs if replacement is indicated. If one is weak or bad, the other one probably isn't far behind.