cam solenoid and P0171 Bank 1 Lean

[RickHaleParker]

Cleaning it was easy but it also did not change a thing

It could still be Damaged (MAF) sensor.

Work down the list before you start throwing money at it:

1. Contaminated engine oil or Oil level too high.
2. Fuel pressure too high or too low.
3. Air leakage.
4. Leaking evaporative emission system (EVAP).
5. Leaking fuel injectors.

[abscate]

Look at the short term fuel trim at idle and at 2500 rpm. If it drops down to less than 5%, you’ve got unmetered air coming in, aka a vacuum or induction leak

[IslandV70]

Cleaning it was easy but it also did not change a thing

It could still be Damaged (MAF) sensor.

Work down the list before you start throwing money at it:

1. Contaminated engine oil or Oil level too high.
2. Fuel pressure too high or too low.
3. Air leakage.
4. Leaking evaporative emission system (EVAP).
5. Leaking fuel injectors.

1. Changed the oil recently and the level is good.
2. It seems to hang around 52-56 PSI. I can check and get an exact number.
3. No idea???
4. No idea???
5. No idea???

Thanks for those ideas, I need to figure out how to check some of them. The MAF could actually just be bad too I guess.

[RickHaleParker]

Smoke test for #3 & #4.
Google "DIY EVAP smoke machine" for all kinds of ways to do a smoke test economy.

You can check for air leaks on the intake with starting fluid. Spray the starting fluid around the intake. If there is a leak it will suck in starting fluid and you will hear the engine rev up. Stop spraying when and if it revs up.

[DrDan]

To diagnose the MAF, you can compare measured airflow to reference values in VIDA.
If you don't have VIDA, in principle, the same check can be made by measuring signal voltage with a DMM, but it's not so convenient and someone (on here?) would need to help out with a reference value...

[IslandV70]

I might be investing in VIDA/DICE. I checked the fuel pressure and it is 54-55 PSI or so. I let the car sit for the morning with the battery off to reset the fuel trims and see what that does.

[IslandV70]

So far so good - no codes after the battery reset. I won't be sure for a while though, the code tended to come and go. I think I do need VIDA/DICE, I get the feeling there is a lot more info to be had than what the generic codes tell you. I did mange to fix the air temperature, ever since I bolted the damn thermostat thing in the cold air position the IAT has been more or less the same as the ambient air instead of 120 degrees on a cold day.

[IslandV70]

Never mind, it came back

[EngineeringBloke]

How did you clean the MAF?

The MAF unit has a visible air temperature sensor - the tiny cylinder (a thermistor), on a loop of wire - on top of the sensing unit held by the two screws - that provides the IAT reading, but the airflow measurement is from a hot film plate sensor that is inside the tiny ducting of the sensing unit.

The ducting is designed so that dirt and liquids readily bypass the film sensor and avoid contaminating it.

It is important to use MAF cleaner only, and to spray it down inside the ducting of the sensor but at a steep angle from the tip of the sensor.

On the Bosch site, there is a video that shows the air pathway (at 0:30)
https://www.boschautoparts.com/en/auto/ ... ow-sensors

Based on the content of the video, I wonder if cleaning does just fix a dirty IAT in the MAF and that that is what is needed. OR that disconnecting the MAF electrical connector may clean the contacts or wiggle loose wires or pins?


Lean air to fuel ratio

A lean condition is too much air for the amount of fuel when the mix is measured in the exhaust by the front O2 sensor. This is too much air, or too little fuel. To address this condition, the ECM will reduce the air or increase the fuel (setting a fuel trim level). However, it is likely that extra fuel will be supplied while this condition is present.

If the sensors are not dirty/broken, and are reading accurately, then there is an air or fuel leak. Or it may be that a 'bad' MAF is under-reading the air flow, and so the ECM is directing extra air intentionally but erroneously.

Extra air can come from a leakage in the air intake - loose air hose/pipe clamps, or tears in the hoses or similar issues with the vacuum hoses.

Fuel can be lost from the fuel injectors out of the engine at the fuel rail or manifold, if the injector o-rings are aged or damaged.

The injector fuel holes may be partially blocked preventing the expected fuel from being delivered to the manifold. Requiring cleaning or replacing.

The o-rings can be replaced cheaply, or the injectors at higher cost. When I tried to replace an injector microfilter, I damaged the filter and failed to remove the filter so ended up getting one new injector. Be careful if you decide to work on the injector microfilter. Either use a microfilter removal tool, or a #10 sheet metal screw held in a vice may work - I have not yet done this step myself.

[Gouws]

Hi all....how can i self test whitch of my transmission solenoide's are not working no more please......transmission slipping and whant to test the solenoids already out off transmission