Automobile / Mazda / RX7

Mazda RX7 Repair Questions and Answers

Question: 1992 Mazda RX7 Turbo 13B mileage: 129,000. I am having a problem with my acceleration. If I only put the throttle down a little bit before half way, the car runs fine. It will boost and accelerate all the way to 7000 if I wanted it to. But if I push the throttle past half way, it stutters, and feels sluggish, if I floor it the check engine light comes on. It is intermittent though, because sometimes it will go when floored and sometimes it won't. I've put new secondary injectors, oxygen sensor, and bac valve. What could be the problem, the TPS? Or the boost sensor?

Answer: Check the fuel filter, fuel pump and fuel pressure regulator to make sure they are all functioning properly. Also, check the catalytic converters to make sure they are not plugged.

Question: 1991 Mazda RX 7 mileage: 130,000.  I have a question about backfire on this car.  I adjusted the timing and it took most of it out.  Most of it was when you would turn off the engine.  Now it is just like a little "put" instead of a stick of dynamite.  When I am in 5th gear not using the gas, it backfires really loud when it drops down to 3000 RPM.  What causes this and how do I stop the backfire at shutdown and the 3000-RPM in fifth gear?  

Answer:  Check the anti-backfire valve located by the carburetor as it sounds like it may be malfunctioning.

Question:  1985 Mazda RX7  mileage: 150,000.  I see that other people asking questions have had acceleration/power issues.  I'm not sure if my problem is different.  I bought the car new in 1985 in Canada, and installed a Rotary Engineering high performance exhaust system in 1989.  In 1998, I relocated to Connecticut and had to install a (new) stock exhaust again to pass emission testing.  I also had intake problems that seemed to be solved with a new shutter coasting valve, valve diaphragm, and fuel filter.  At the same time, I also replaced the clutch.  However, now I have no acceleration.  I can accelerate to redline in second gear without moving faster than 10 mph.  The shop that did the work (on everything except the exhaust) assures me that the clutch is fine, and they sounded like they were grasping at straws when they suggested a compression test, so I declined (besides, I was convinced they were bleeding me financially).  And if that wasn't enough, it is starting to drop oil - about a cup every 6 weeks (I'm not driving it, so it's easy to measure).  So I have 2 questions: 1.  Any ideas as to the problem?  2. Know any good rotary mechanics around or near Fairfield County in Connecticut (other than the ONE Mazda dealership)?

Answer:  If the car is only going 10 mph in second gear and the engine rpm is close to redline, the clutch has got to be slipping.  Sorry we do not know any mechanics in your area.  Check with friends and neighbors to locate a mechanic you can trust.

Question:  1986 Mazda RX7 rotary mileage: 99,000.  I need to replace the 4 fuel injectors and am having trouble finding where 2 of them are located on the engine. Can you help me?

Answer:   The two injectors you are looking for are down low under the intake manifold – not easy to find,

Question:  1982 Mazda RX7  mileage: 142,000.  I get in and try to start the car.  It cranks but will not start.  I've gone through the Haynes book as best I can for now and have checked the battery, spark plugs (new and I took one out and watched it spark), all electrical connections, fuel filter (new), and fuel pump.  What else can I do in my garage?  Should I just have the car towed to a garage?  It’s the first car I've tried to work on and so far, it’s been fun but now I'm finding myself at a dead end.

Answer:    Check to see that the carburetor is delivering fuel to the engine.  Check the engine compression; it should be at least 90 PSI.

Question:  1990 Mazda RX7 GTU  mileage: 100,000.  My son replaced the battery cables and the battery when the car wouldn't start; still no good.  Next he replaced the main fuse and tried to start it--blew the fuse.  Have you any idea where in the wiring he should look first (I don't know anything about cars, you might guess).  The problem is also that I just replaced the clutch and this car now seems Hopeless.  The dealer got my money and now is not helpful.  (You probably hear complaints a lot--sorry) help, please.

Answer:    Check the ground straps from the engine/transmission to the frame.  One may be loose or left off.

Question:  1985 Mazda RX7 mileage: 125,000. My daughter's RX7 - Rotary engine- has lost acceleration. Its like it is starving for fuel. Although, we can give it gas and the idle goes up. We do that to keep it from stalling. Although its bad enough that she can't drive it, except around town. What do you think this is?

Answer: Perform a compression check to determine the condition of the engine. Check to see that the exhaust is not plugged or restricted, especially the catalytic converter. Check the fuel pump pressure, your fuel pump may be bad.

Question:  1991 Mazda RX7 mileage: 140,000: Car will not start when you turn key in ignition, there is nothing (sound). The battery is new and the alternator is also new, both replaced in August. ALL power items are working i.e. windows, radio/antenna, convertible, etc.

Answer: Check for 12 volts to the starter solenoid with the key in the start position. Check that the engine is not frozen; can it be turned over by hand (wrench on crank pulley)? If the above items are okay, the starter may be at fault.

Automobile / Mazda / RX7

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