# Did a compression test - How's it look?



## Teerump (Sep 29, 2014)

If you guys have been following my other thread about dumping fuel into the exhaust, as many suggested to do a compression test, I did one today.

Here are my numbers, tell me what you guys think. The car is completely stock with 74,000 miles.

I'm going to post the first crank and last crank, we let it crank 5 times.
1st crank is in parenthesis.

#1 (30) 150
#2 (40) 148
#3 (40) 155
#4 (40) 150
#5 (30) 152
#6 (40) 150
#7 (35) 148
#8 (35) 150


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## Lemans guy (Oct 14, 2014)

T...compression should be between 140 and 160 with no more tha a 10% difference between the cylinders....your lowest is 148 your highest is 155........10% percent would be 15 and you are within 7

That looks good to me, now I suppose one could try to pick apart the 155 to the 148 etc, but hardly relevant.

I say you are good there dumping too much fuel is a carb problem. 

Had the same thing on my Lemans when PO put on a two big 4bbl, just dumped fuel until I put the right carb on it. Could not turn the mixture down.


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## svede1212 (Nov 1, 2005)

What is this "carb" thing you speak of?


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## Teerump (Sep 29, 2014)

Lemans guy said:


> T...compression should be between 140 and 160 with no more tha a 10% difference between the cylinders....your lowest is 148 your highest is 155........10% percent would be 15 and you are within 7
> 
> That looks good to me, now I suppose one could try to pick apart the 155 to the 148 etc, but hardly relevant.
> 
> ...


Yeah the fuel problem was a shorted wire to one of the fuel injectors, so it was stuck open.

I still think I have a clogged catalytic converter. Taking it in Tuesday to hopefully find out for sure. Mechanic is going to do full diagnostics, and a back pressure test.


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## HP11 (Apr 11, 2009)

Raw fuel will superheat the monolith in the converter and cause it to melt which will clog it.


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## Teerump (Sep 29, 2014)

HP11 said:


> Raw fuel will superheat the monolith in the converter and cause it to melt which will clog it.


Thanks for the tip!


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