Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: dthebuk on June 25, 2008, 03:21:20 PM

Title: So i think i fixed the lack of compression??
Post by: dthebuk on June 25, 2008, 03:21:20 PM
basically i got a compression test a while ago which was around 5.9-6.1 over the 6 faces. I also had troubles with warm starts and an erratic idle when the car was warm.

So looking through the haynes manual to fix the idle, it suggested checking for air leaks. So i looked around and guess what i found. One of the nuts from the top of the air intake manifold (i think thats its correct name) was missing, this left a slight gap. Tightened it up and now the idle problem has gone. The car also now seems to have a bit more power. So the big question is; could the engine have had low compression because of this missing nut?


please say yes :D


cheers
Title: So i think i fixed the lack of compression??
Post by: Brett on June 25, 2008, 03:25:27 PM
Sadly not - the compression cycle takes palce within the confines of the housing :(
Title: So i think i fixed the lack of compression??
Post by: BlitzBoy on June 25, 2008, 03:26:05 PM
ermm afraid no but at least you fixed your idle and you will have more power coz you fixed the air leak
Title: So i think i fixed the lack of compression??
Post by: TiddlesRX7 on June 25, 2008, 04:38:01 PM
so what value is low compression classed as then? Anything below 6?
Title: So i think i fixed the lack of compression??
Post by: BlitzBoy on June 25, 2008, 04:45:00 PM
yep you are correct sir, you lose a bit of power, but it can run on low compression for another 10K
Title: So i think i fixed the lack of compression??
Post by: dthebuk on June 25, 2008, 05:06:08 PM
i best start saving for a new engine then:D

my logic was that maybe if its not taking in enough air then the air pressure in the engine would drop. So when the compression tester is used it reads a lower pressure


once again thanks for the help
Title: So i think i fixed the lack of compression??
Post by: Grizzly on June 25, 2008, 08:08:29 PM
If its even and idling etc ok i would leave it until it starts causing you problems, i have had one down into the low 5\'s and and that used a little more fuel / felt a bit down on power but i drove it for a year and to my knolage is still going now.