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Very Low Compression


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#1 mckenziecz

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Posted 14 June 2013 - 07:53 PM

Hi there,

 

I have done dry test on my girlfriends mini. I got 25 psi which is obviously incredibly low number. The things is it was same on all cylinders. I had all plugs out, what and petrol line clamped. The test was done by cheap untested gauge so i though it was the gauge.

I then tried to test my mates focus the only petrol car available to me and have reading around 85psi which seems low so the gauge is probably reading half the amount. not sure what the compression of focus is.

 

Would my girlfriends mini even move with figures like that?

 

 

Thank you



#2 Island Mini

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Posted 14 June 2013 - 09:23 PM

Don't know for sure but I would say it would barely run let alone start! If it is running okay I would say your gauge (make sure you don't have any air leaks on the gauge) if you are still having problems I would say off with her head!!

#3 Stevie W

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Posted 16 June 2013 - 06:18 PM

Hi,

Judging by the low compression on both your Mini and your mates Focus, I would think there's a strong chance your compression tester is kaput!!!
25psi would barely be enough to compress the fuel/air mixture for the spark plugs to ignite it!

Before whipping the head off I would invest in a new tester. What prompted you to measure the compression in the first place? Is your Mini down on power or mis-firing?

If this was the case, by all means try a new tester, but if it's running rough it could be ignition or carburation problems.

Cheers, Steve.

#4 Yoda

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Posted 16 June 2013 - 06:40 PM

Did you have the throttle wide open when you did the test?



#5 sonikk4

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Posted 16 June 2013 - 06:42 PM

Did you have the throttle wide open when you did the test?

 

Even doing that would not make that much difference. The tester must be cack. I did a test on Paddy with the throttle closed and he still showed 160 psi. 

 

And Yoda you are looking quite young on telly at the moment. ITV2



#6 jaydee

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Posted 16 June 2013 - 07:26 PM

At 35 psi it wont even fire, try testing again with throttle wide open and possibly a different tester



#7 Yoda

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Posted 17 June 2013 - 03:39 AM

 


 

And Yoda you are looking quite young on telly at the moment. ITV2

 

 

 

 

Sorry,  watch telly i do not.






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