MFA (2) manifold pressure test..

[G60-NeedMoorePoower 0]

"" 1. Start engine

2. Move the MFA selector to "2"

3. Press and hold the MFA end button (keep holding)

4. Stop engine

5. Start engine

6. Release the MFA end button.

7. Press the MFA End button one time.

 

 

You should now see 550-750 readings fluctuating with idle. Anything higher than 750 is probably not right (a vacuum leak possibly?). Much less than 550 is probably too much timing advance. Run the car to the redline in 3rd and 4th gears noting the highest readings you get

 

== my reading is 240, dropping to 200 stable

 

Running a standard 78mm pulley you should see 11psi if the charger is in good nick but a charger with a smaller pulley should make more than 11.6

 

EURO Hg(#'s of boost/vacuum)

 

200 - 23.7

400 - 17.8

600 - 11.9

800 - 5.9

1000 0 (Atmospheric pressure, charger is bypassed?)

1200 2.9 psi (You have a major boost leak)

1400 5.8 psi (Your charger is in very poor condition)

1600 8.7 psi (Your charger would benefit from new apex strips)

1800 11.6 psi (Good for stock pulley, needs new apex strips if 68mm pulley)

2000 14.5 psi (Good for 68mm pulley on stock charger)

2200 17.4 psi (Good for 68mm pulley on heavily ported charger)

 

Any more than this and you must ensure that the fuelling is seriously up to scratch At this point you are into the realms of different injectors, aftermarket engine management and so forth....""

 

--- my redline reading is only 960 odd !

 

According to the graph above thats near atmospheric pressure....

Could "timing advanced too much" be the only issue I have ?

 

I would need to get a boost gauge yes to check psi ...

 

 

 

Thanks

[Dub_nut_g60 0]

960 at redline in 3rd/4th?

 

Do you have a flowed head? as IIRC these result is no pressure (remember pressure is due to restrictions in the flow of air) therefore there is nothing to worry about

 

BUT If not you will need to investigate, as it effectively means the charger is doing nowt.

 

My idle values are around 200 i think, and the highest boost i saw from the MFA was 2200, but i think my engine map ran out there as it was nowhere near the redline.

[G60-NeedMoorePoower 0]

960 at redline in 3rd/4th?

 

Do you have a flowed head? as IIRC these result is no pressure (remember pressure is due to restrictions in the flow of air) therefore there is nothing to worry about

 

BUT If not you will need to investigate, as it effectively means the charger is doing nowt.

 

My idle values are around 200 i think, and the highest boost i saw from the MFA was 2200, but i think my engine map ran out there as it was nowhere near the redline.

 

Well according to the test idle should be in the 650 mark..? So if your idle is 200 odd that

means I have no timing problem, however charger needs overhaul or something else...

 

??

[G60-NeedMoorePoower 0]

960 at redline in 3rd/4th?

 

Do you have a flowed head? as IIRC these result is no pressure (remember pressure is due to restrictions in the flow of air) therefore there is nothing to worry about

 

BUT If not you will need to investigate, as it effectively means the charger is doing nowt.

 

My idle values are around 200 i think, and the highest boost i saw from the MFA was 2200, but i think my engine map ran out there as it was nowhere near the redline.

 

Don't know anything about the head, only just bought it...never met the prev owner...

[G60-NeedMoorePoower 0]

"..960 at redline in 3rd/4th? ..."

 

Yip - 3rd

[G60-NeedMoorePoower 0]

I'll try the boost test as per Wiki.....