Now that's what I call a useful explanation!! I would be interested to know.....with all the low MAF readings, what are the different causes that you have found that cause the low MAF reading. This point is coming back to an earlier post, where you might have a symptom, but you need to get...

But then if there was plenty of leeway......... wouldn't the ECU have done it already? Problem solving is a series of logical steps of IF ......THEN repeated over and over based on hypotheses. I can provide many IFs and THENs, but if you don't like my IFs, please just ignore them, don't...

But then tricking a MAF into thinking that more air is going in is one point BUT, What if the ECU has a limited range over which it can add fuel? If the fuel trim is already as rich as the ECU can possibly make it at the rev point, and if there is a limit on the airflow at that rev...

Me not making sense? This last test doesn't make any sense to me at all, but I accept I can be dim, a little slow, but please be patient. Why not find the airleak? Loose throttle bodies and manifolds are an obvious culprit. Let's open the throttle / idle control and restrict the...

There are different manifolds for the V8, so it depends on which one you have. Ask the engine supplier / builder, they should know if it is an SAI one, if and how it was blanked off, and if any blanking was necessary. If there is a constant sized hole, then the flow through it will be...

plugs, leads, air leak, endless list. Either get some data on lambda values or emissions - gas analysis, or when were the service items - plugs, leads, coils, distributor cap/rotor done?

Bank 1 = left hand side Bank 2 = right hand side (drivers side in the UK) This is looking at the front of the car as far as I know.

Is the idle control valve closed more than normal? Some engines have the valve half open to give some leeway to increase/decrease the engine speed. The duty cycle would be around 50% but it depends on the valve. If there is a large airleak, then the valve would probably be closed completely...

If this is an air leak, an exhaust gas analyser would show this, without relying on the lambda sensor data. There are many ways to skin a cat. On checking the brake servo, disconnect the pipe and blank it off, tape or rubber bung, but do the testing when stationary. I wouldn't want you to...

The voltages won't cycle if it's not going closed loop, it will be a monitoring output only. This is because you need the ECU to change the fueling as the voltage changes, i.e. a feedback mechanism.

As WSLR says about the MAF readings, an airleak will make the MAF readings lower than normal at each engine speed.

Looking at the voltages, 0.3V is almost stoichiometric and 0.08V is about 20% lean. If the fuel trims are having to adjust 20% - about the maximum possible, it looks like a lot of excess air is getting in somewhere.

Bank 1 is lower than bank 2, which could mean that an air leak is nearer to that bank, or on the inlet manifold - head in the V for that bank.

There we go, not going over 0.35 as the garage said is the lambda sensor voltage. That means it is picking up a lean mixture, which it is shifting the short term fuel trims as positive as possible, to try and get the mixture correct So why isn't it managing? Blocked injectors? Low fuel...

On the WD40, it says on the can that it doesn't contain silicones, my mistake!!

You could look at the EGR valve to see if that has failed. It could be open too much, knackering the combustion, of course eightinavee can correct me if I am wrong. With too much EGR it won't matter what the lambda sensor says, because poor combustion will always result in high HC/CO and...

Sorry that you don't feel my contribution is helping. With any engine diagnosis you have a load of sensors that tell the ECU what is happening and then the ECU supposedly does it's calculations for fuelling and ignition timing, operating the injectors and coils. Beyond that either all...

The lambda sensors and ECUs changed for different years. What year is your ECU for and do you have the correct lambda sensors for that year of ECU? You did say about going from SAI type to non-SAI type.

If you are really unlucky with the engine build, there might be silicon poisoning of the lambda sensors. That screws them up pretty quickly. Did anyone squirt a load of WD40?

With the sensors, if you got the secondary sensors fitted where the primary sensors should be, and the primaries fitted where the secondaries should be, then depending on the sensors if they are zirconia or titania type, and they could cause a problem for the ECU. The ECU might not know what...