95 5.0 running lean/ rich adaptive limit reached

[Pipstar]

I have a 95 gt that has a BBK cold air intake, BBK mass air flow, svo intake manifold. I keep getting a code for running lean/rich adaptive limit reached. I was unable to find any vacuum leaks. And while driving the rpms hang at a high idle with the clutch in until the car is brought to a stop. Any insight would be greatly appreciated.

 

[KRUISR]

Have you checked the O2 sensors?

 

[WhiteCobra95]

What ECU are your running?
What injectors are installed?
What injectors is the MAF setup to use?
Are you running a chip of any type?
As mentioned above, are your O2 sensors in good shape?
Is the DTC for both banks?
Do you have any exhaust leaks (head-to-header, header-to-H pipe, around the O2 sensor seal)?

It sounds like something is mismatched in the setup if it's setting that DTC. You're not metering either the air or fuel correctly, and this is winding up the control authority of the lambda control. It could always be an exhaust leak that's poisoning the O2 sensor's reading, but it would have to be a good sized leak to max out the control range. Do you know if it's adding or pulling fuel?

 

[manicmechanic007]

What specific code is it? and then follow the pinpoint test steps for that code is a good start

 

[manicmechanic007]

Like the above post
It might be adding fuel if you have an intake manifold leak
It might be subtracting fuel if you have drizzling or leaking injectors
You need the specific code

 

[Pipstar]

New 02 sensors, stock injectors with maf to match (18 or 19 lbs?) Stock ECU, and no chips. It was both banks I believe. I would assume it's adding fuel smells extremely rich. I sprayed all the vacuum lines and gaskets I could reach with carb cleaner, no change in idle to indicate a leak. I'll have to pull the code again, I don't have it written down.

 

[Pipstar]

I bought the car with this set up, did not install anything myself.

 

[Pipstar]

No noticeable exhaust leaks, it is a catless system, BBK short headers, full aftermarket exhaust

 

[WhiteCobra95]

Have you checked your fuel rail pressure? I wonder if your fuel pressure regulator is giving up.

 

[manicmechanic007]

Monitor those front O2 sensors and see if they are slammed?
You retrieve the code(s) yet?

 

[Pipstar]

Sorry guys, been a little busy. I've been slowly chasing this problem for 4 years. So I checked the fuel pressure last summer, it was around 49lbs, if I remember correctly. I ran a code check yesterday, no codes came up. I think I cleared the codes when I parked it for the winter. I ran a running diagnostic on it yesterday also, o2 sensors are working fine at idle, reading between .33 volts and..75 volts, egr functions in range, tps in range, IAC in range and intake air temp in range. Still didn't find any exhaust leaks.

 

[Pipstar]

It still smells rich, and pings under heavy load

 

[manicmechanic007]

49 lbs is too high for the fuel pressure
It should be 30 to 35 and maybe 38-40 with the vacuum line pulled off the regulator
Check for an intake manifold vacuum leak

 

[96pushrod]

With no cats it’s just going to smell like fuel, no escaping that. Noses are a terrible indicator of air fuel ratio.

I’d confirm fuel pressure, because it shouldn’t be 49psi. If you cleared codes and none came up, that’s good.

Take the spout out and put a timing light on the car. What does it read?

 

[Pipstar]

With the diagnostic computer it read 20 degrees of spark advance.

 

[manicmechanic007]

What do you mean diagnostic computer?
Base timing is10 degrees right?

 

[Pipstar]

Using an auto xray easy scan with car running it reads 20 degrees of spark advance. I didn't have a chance to put the timing light on it, hopefully tomorrow evening

 

[Pipstar]

I believe base is 10

 

[manicmechanic007]

The timing will be all over the place running with the spout plug in
Verify the base timing and go from there

 

[manicmechanic007]

What is the Auto Xray Easy Scan you mention Pipstar?