anyone help me out with this?

I have popped up lean codes for a few days now and when this has happened before its usually a vacuum leak at the breather hoses on rs of engine , now I have checked and double checked for any air getting in and can't find any.

so my next train of thought is the MAF going bad

I get the following on a hot engine

idle 5.8-6.2 g/s thats after giving it a bit of revs

1000 rpm 7.6
2000 14.7
3000 25.8
4000 35.6


can anyone with a 4.2 s/c do a comparison for me?


thanks in advance

I’ll give it a go on Monday afternoon for you. If somebody else beats me to it that’s OK I’ll check it out anyway then you can get a better average. 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

thanks mulcher

its the unsteadiness of the idle count thats suspect but I took one reading at idle then another after the 1000rpm X 4 stage readings and thats when it started fluctuating a bit , if you do it in the same manner that would be great.

I should be able to check this for you today

Here ya go - this was with the following conditions:
Air temp 5 (as read by the car and indicated on the dash)
Oil temp 85 (Oil is Castrol 15990F Magnatec 5W-30 (changed in July) )
Coolant temp 92
Air con switched off (check you had this off)
Readings via IIDTool BT.


Car hd just driven 20 miles. Engine has 84000 miles on it.

Idle - 5.5 (this was varying between 5.4 and 5.6 but was mainly at 5.5)
1000 - 7
2000 - 14.5
3000- 23
4000- 34

There was no noticeable wobble at any of these RPM's.

Hope it helps

thanks for going to the trouble of getting those readings for me

air flow meter was not the issue , discovered that the engine cover was pressing just a little bit on the breather hose enough to make the push connection (they are crap btw) a little squint in its recess and letting in a little bit of air.

problem now resolved

Doh, just got back indoors after running the tests. Glad you sussed it, here’s my readings for interest:

Idle 5.9-6.2
1000 8.4
2000 16.0
3000 26.5
4000 36.5 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

thanks mulcher

all ours look in a similar ballpark anyway