Lack of power on replaced engine

i just got my engine and clutch replaced in my 1993 300zx. when i test drove it today, the response was not what i expected. it ran slower than my Chevy caviler. the engine was less than 70k miles on it, any suggestions?

Was the engine known to be good when you bought it?
Did it have a compression test and a leak down test done before/after installation into your 300Z?

Is the motor actually from a car comparable to your 300Z?


yeah it has a 3 year warranty, unlimited miles. i am taking it back today more a compression test. is sounds like a truck when i am driving it, it sounds like alot of air in sucking in

Who did the installation??

an auto repair shop

i paid 3500 for the work

is there anything else that i should ask the shop to look for?

plugged converters ?

sounds an awful lot like a vacume leak someplace to me.

thats what i was thinking

no their new also

i am going to ask them to check for leaks today

they are telling me that i just have to run it for a while and to use engine cleaner to clean out the engine of old gas, are they right?