Hi all, again..
I am looking into a few issues with my 4.4 petrol 2004 engine, just trying to make sure it is running as it should and not causing my transmission issue from my other thread if somebody can help.

I have run a few diagnostic reports using a faultmate and there are a couple of readings that don't look right to me that i have attached.

In particular i am looking at the cam adaption values being very different for the two different banks which is shown in degrees. I believe the adaption values should be between 0, fully retarded and 20 degrees fully advanced.

The throttle position shows as unlearned so i cleared the adaption values which put it into an emergency mode and it then showed as learned but then very quickly returned to unlearned although i may not have carried out the procedure correctly.

The air leakage showed at around 5 kg/h so I cleaned the MAF sensor and throttle body and really made sure i put it back correctly and sealed it but the total air flow increased and the leakage increased to around 10 kg/h, but weirdly, if i wiggle the wires connected to the MAF sensor, the value will drop to around 8 kg/h.

Anyone make any sense of these please, i have other pages of information as well.

Many thanks
Andy

What s the symptoms ?
Start with some MAF readings. These below are known good ones.
All loads off engine up to temperature.
600rpm idle - 17.1 Kg/hr.
2000rpm - 44Kg/hr.
3000rpm - 76Kg/hr.

Hi, thanks very much for the reply, quite a long story short, I have an issue that when I drive slowly and let off the throttle and back on again I get a clunk from my drivetrain and I have read the fault on later models has been rectified by updating the engine ECU. I also went to an Indy and his Autologic said my ECU needed an update but as we couldn't really see much wrong with the drive train with it on a ramp and wasn't confident about the update so we left it but he did say to make sure the engine is running as it should and to clean the MAF sensor and throttle body and check for air leaks.

The engine idles steady at 600 but when I first touch the throttle I can get a dip in the revs a bit like the link below and then the idle can waver up and down a bit before settling back to 600.

i was also concerned about the cam adaption values being so different for the different banks knowing i have a noisy vanos.

Do you have any readings for the air leak values or ideally should it be zero?



This is the reading before I cleaned the throttle body and MAF sensor showing 17.9 Kg/h @ 600 rpm.



And this is after showing 22.5 kg/h @600 rpm, but the leakage increased to around 10 from 5 kg/h




I'll take some more readings this weekend and see if it has settled down.
thanks very much for your help.
Andy

Have you had a look at the breather pipes and the Pcv valve on the back of the inlet? When you cleaned the maf, did you reset the fueling adaptions ,.? Forget the lpg until she's running sweet on petrol. Any pulsing from the airbox when it's running ?

hi,
I reset the adaptions on the attached page below and then i re learned the throttle position by turning the ignition to position 2 for 30 seconds and then off and it showed as learned. I notice that when i turn off the ignition and back on again and go back into the same page it says throttle not learned but I guess you just do it once.

When we rebuilt the transmission the pipes at the back of the engine were just mush but we didn't replace the pcv valve at the time due to funds and not realising how common a failure is and how tricky they are to change when the transmission is back in.
I have a new one now but haven't fitted it as it looked like a real pain and I tested the existing one according to a procedure I found on the net using a home made manometer which appeared to be good.

I changed the cam cover seals but I have noticed my timing chain cover seals are also leaking and I am destined to change the vanos seals at some point so I am going to do the PCV valve then.

I am not sure what to look / listen for regarding pulsing from the air box, at a guess a pulsing noise from the airbox ?

I tried testing the vacuum system using the 'cigar method' I saw on youtube by blowing smoke as hard as I could down the pipe that leads to the brake servo, I couldn't see any leaks and can confirm this method tastes disgusting and probably doesn't work unless you have a gaping vacuum leak.

Ok, start with basics. Are O2 sensors switching nicely when warm. Between 0 and .8v every second or so. Any big differences between banks one and two ?

Ok, that's me out of my depth, I don't have any upstream faults regarding upstream o2 sensors but I do with downstream sensors but I don't think that matters ?
Will faultmate tell me about the o2 sensors voltage?
I don't have LPG, forgot to mention

You should be able to see live data on the faultmate. Front ones should switch every second or so between 0 and .8 v and the rears should stay reasonably static at about .45v

ok, standby for update, I'll plug it in later today, thanks very much for your help so far