Running Really Rich!

[ReefBlueHatch]

My car has always ran rich, but lately it seems to be getting worse. Terrible strong exhaust smell and blows black smoke when floored. My cars has GT40P heads - so no EGR, air pump, and cats on my car. I know this contributes to the exhaust smell, but the rich smoke under acceleration has me concerned. It threw obvious codes with the EGR/smog stuff missing.

31 - EVP or PFE voltage low
67- Neutral switch (car was in neutral)
81- Air diverter solenoid fault/ IAC circuit fault/ Air injector diverter
82- Intergrated relay control module / air diverter solenoid circuit fault
84- EGR vacum regulator circuit fault

The wondering about my O2 sensors. Anyone have some ideas?

 

[jrichker]

With a code 67 you will not get the engine running codes, and have only half the diagnostic info needed to fix the problem.

Code 67 –
Revised 2 Nov 2012 to add definition of the NSS functions for both 5 speed and auto transmissions

Cause of problem:
clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests. External evidence from other sources claims that a code 67 can cause an idle surge condition. Do try to find and fix any issues with the switch and wiring if you get a code 67.

What the NSS (Neutral Safety Switch) does:
5 speed transmission: It has no connection with the starter, and the engine can be cranked without it being connected.
Auto transmission: It is the safety interlock that prevents the starter from cranking the engine with the transmission in gear.
What it does for both 5 speed and auto transmission cars:
The computer wants to make sure the A/C is off due to the added load on the engine for the engine running computer diagnostic tests. It also checks to see that the transmission is in Neutral (5 speed and auto transmission) and the clutch depressed (T5, T56, Tremec 3550 & TKO)). This prevents the diagnostics from being run when the car is driven. Key On Engine Running test mode takes the throttle control away from the driver for several tests. This could prove hazardous if the computer was jumpered into test mode and then driven.

The following is for 5 speed cars only.
The NSS code 67 can be bypassed for testing. You will need to temporarily ground computer pin 30 to the chassis. Computer pin 30 uses a Lt blue/yellow wire. Remove the passenger side kick panel and then remove the plastic cover from the computer wiring connector. Use a safety pin to probe the connector from the rear. Jumper the safety pin to the ground near the computer.
Be sure to remove the jumper BEFORE attempting to drive the car!!!

 

[ReefBlueHatch]

Can I get around the code 67 if the clutch is pushed in while dumping codes? My car is a factory A/C delete car - is it possible it throws the 67 code due to lack of A/C?

 

[Mustang5L5]

Yes. Hold the clutch in the entire time you are running codes. That should eliminate the code 67.

Are those engine running codes? Or did you pull codes with the engine off? Also, did you perform a cylinder balance test?

 

[ReefBlueHatch]

I pulled the codes with the engine off. I just bought a code reader yesterday so this is the first I've used one.

 

[Mustang5L5]

Ah, so you missed half the codes really.

Once the engine off codes are complete, then you can start the engine and get the engine running codes. These are different and will include things like O2 sensors and MAF codes and stuff that can only be checked while the engine is running

 

[ReefBlueHatch]

OK thanks, Mike. I'll give it another shot with the engine running and someone to push the clutch. Is it best to pull codes with a warm engine?

 

[ReefBlueHatch]

So here's what I have with a running engine at normal temp:

94 - Air diverter solenoid circuit fault
44 - Thermactor air system fault
31 - EVP or PFE voltage low

But here is a problem I had with the tester. The first step the tester identifies is the number of cylinders and my tester read 6. So I don't know if that's a fault with the tester or the car.

 

[slow5ohgt]

All three of those codes will be thrown because the EGR system is removed. Your problem sounds notoriously like a leaky map vacuum hose.

 

[Mustang5L5]

Ignore the 6 cyl indicator. Happens a lot.


Most of the codes are harmless, except the EGR code. However the code 31 should disable the function in the computer.

Does your reader have instructions on the cylinder balance test procedure?

Sent from my iPhone 4S using Tapatalk

 

[mikestang63]

Throw away that tester and use the paper clip method, Run the KOER codes and the cylinder balance test. X2 on the vacuum leak. Other things could be bad O2 sensors.