1989 Mazda RX-7 No Start Low Compression Fix

1989 MAZDA RX7
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MAVERICK
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  • 1 POST
I have just received a 1989 Mazda RX-7 GXL 102k miles. The only problem with it is that it will not start. The person that i bought it off of said that the engine would start when he parked it. I have cleaned the spark plugs and tried starting it but all it will do is turn over. The guy said that the rear rotor had only 25 compression but the front rotor had 110. he said that it would start like this but do i need to get a tester and see if the compression is that and then decide if i have to rebuild the engine or do i try the feul pumps and everything. plz help me.
Sep 26, 2006 at 10:27 AM
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COSMO
  • ✓Experienced Mechanic
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Well if the rear rotor only has 25 psi of comprssion, its time to have a rebuild. Plus if he says there is 110 psi on the front....he's either lying or not testing it right. Comprssion readings should be around the 80-95 psi on that motor....anything under 65 psi is weak

Cosmo
Sep 27, 2006 at 4:44 AM
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Suggested Repair

Have the rotary engine rebuilt. Reported rear-rotor compression of 25 psi is far too low, and a proper reading should be about 80-95 psi; anything under 65 psi is weak. Recheck compression correctly rather than relying on the reported 110 psi front-rotor reading.

Conversation Summary

The owner of a 1989 Mazda RX-7 with 102,000 miles says it only cranks and will not start after the seller claimed it started when parked. The seller reported 25 psi on the rear rotor and 110 psi on the front. The expert says the rear rotor needs a rebuild, notes that normal compression is about 80-95 psi and under 65 psi is weak, and doubts the 110 psi front reading.

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