This one is really for DiscoMike or anyone else that can help.
THE FACTS:
-Running Rich, Poor Mileage (worse than stock which we all know is not too good), and Poor Performance
-Had code 44
-Performed induction cleaning BG44k, changed plugs, changed O2 Sensors (both sides)
-Things were good, then tripped a code 44 again, back to the same symptoms
-after driving around, she would shut off as if you ran out of gas...would only start back off when car cooled down tripped code 48
-removed the Stepper motor cleaned evertything...put it back together...things seemed fine
-the shut down happened again, was able to start it back up, but no code
-happened one last time, now runs rather rough and wants to hesitate when you blip the throttle
SO.....
Still running rich, poor mileage, no performance, and no trust! Help Please!!!!

 

Check out the faults codes and suggestion, especially for the 48.
http://www.fourfold.org/LR_FAQ/RR/FA...ult.Codes.html

 

Hi from Oz. Have you considered that the AFM/AMM might be unserviceable? Sounds like where I'd be starting. See if you can check the unit by substitution.

Probably Lucas 5AM. We have had a similar problem on one of our earlier RRCs.

HTH

Pete

 

Sorry Guys...what the AFM/AMM?????

Thanks-

 

Air flow meter / Air mass meter

 

My guess would be a plugged cat.

 

A MAF won't cause an engine to run rich, they cause them to run lean.

 

After about $1000 from changing the O2 sensors to a complete top end rebuild...it turns out there was an intake leak that was causing the ALL the misreadings.

Now she runs honestly twice as fast and MUCH better mileage...its like a whole new rig.

Thanks for all the help. Now in the process of bringing the paint back to life via clay bar, polishing compound, and cleaner wax.

 

You have a lot of symptoms there! Likely multiple issues.

Let's start from the top. That is what the Hotwire diagnostic system does...shows codes by some weird priority it decides. Can't see the next one until the ones before are cleared

44 is the code for a left bank Lambda (O2) sensor fault. You should test it.

When testing your O2 sensor, you must be careful to not apply voltage to the sensor. But measuring its output voltage is not harmful. Testing can be done with the sensor in or out of the car. If you have a high impedence voltmeter, the procedure is fairly simple. The engine must first be fully warm. Attach the positive lead of a high impedence DC voltmeter to the O2 sensor output wire. This wire should remain attached to the computer. (You will have to back probe the connection or use a jumper wire to get access.)

The negative lead should be attached to a good clean ground on the engine block or accessory bracket. Cheap voltmeters will not give accurate results because they load down the circuit and absorb the voltage that they are attempting to measure. An acceptable value is 1,000,000 ohms/ volt or more on the DC voltage. Most (if not all) digital voltmeters meet this need. Few (if any) non-powered analog (needle style) voltmeters do.

Set your meter to look for 1 volt DC. Many late model cars use a heated O2 sensor. These have either two or three wires instead of one. Heated sensors will have 12 volts on one lead, ground on the other, and the sensor signal on the third. If you have two or three wires, use a 15 or higher volt scale on the meter until you know which is the sensor output wire.

Turn the key on, but do not start the engine. You should see a change in voltage on the meter. If not, check your connections. Next, check your leads to make sure you won't wrap up any wires in the belts, etc. then start the engine. You should run the engine above 2000 rpm for two minutes to warm the O2 sensor and try to get into a closed loop. Closed loop operation is indicated by the sensor showing several cross counts per second. It may help to rev the engine between idle and about 3000 rpm several times. The computer recognizes the sensor as hot and active once there are several cross counts. You are looking for voltage to go above and below 0.45 volts. If you see less than 0.2 and more than 0.7 volts and the value changes rapidly, you are through, your sensor is good.

If not, is it steady high (> 0.45) near 0.45 or steady low (< 0.45)? If the voltage is near the middle, you may not be hot yet. Run the engine above 2000 rpm again. If the reading is steady low, add richness by spraying some starter fluid through the air intake. If the voltage now rises, and you can change it at will by spraying, the O2 sensor is usually good.

If the voltage is steady high, create a vacuum leak. Try pulling the PCV valve out of it's hose and letting air enter. If this drives the voltage to 0.2 to 0.3 or less and you can control it at will by opening and closing the vacuum leak, the sensor is usually good.

If you are not able to make a change either way, stop the engine, unhook the sensor wire from the computer harness, and reattach your voltmeter to the sensor output wire. Repeat the rich and lean steps. If you can't get the sensor voltage to change, and you have a good sensor and ground connection, try heating it once more. Repeat the rich and lean steps. If still no voltage or fixed voltage, you have a bad sensor.

That was the right code interpretation and you took the correct action. Well done.

Since you got the spray can of starter fluid out anyway. Give hose connections and the plenum quick sprays to find if there are any vacuum leaks. If the idle changes with the spray (aside from the air intake), you have found a leak.

Hmm... I would like you to test the fuel temperatre sensor. It is the one that is on the fuel rail. However, you should test it at the ECU plug. Here is what you should see at different temps;:

Connect ohmmetre between Pin 25 and 32.

°F ohms

14° 9100-9300
32° 5700-5900
68° 2400-2600
104° 1100-1300
140° 500-700
176° 300-500
212° 150-200

If this checks out, we can move on to some other simple tests.

James

 

I think I jinxed myself...my mechanic called to check how things were and we checked the codes..still 44 (there's an irony that if you hold shift down and type 44 you get $$) anyways...so if the O2 sensors have already been changed and you still have a code is that an issue with the connections or could it be a bad ECU???