1988 Rx7 - Detonation
06-25-12, 08:26 PM
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1988 Rx7 - Detonation
My 1988 RX7 convertible (45,000m) has had a detonation problem for the 10 years I have owned it. Doesn't matter if the engine is cold, warm or hot. Usually premium fuel helps but it still detonates under load. Different tanks of fuel seem to make a lot of difference -always premium- but it is never free of some detonation.
Detonation . . . it makes a terrible metalic clinking noise under load and is sometimes "missing".
Related . .
If there was a Rotary shop in Minnesota I would like to bring it in for service ?
Detonation . . . it makes a terrible metalic clinking noise under load and is sometimes "missing".
Related . .
If there was a Rotary shop in Minnesota I would like to bring it in for service ?
06-25-12, 10:53 PM
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Detonation will destroy a rotary in no time. It's unlikely to last 10 days with constant detonation events, let alone 10 years. I'm going to assume it's just been driven rarely and carefully during that time, otherwise, the engine would have blown by now.
The #1 cause for unexplained detonation in an NA is going to be an improperly stabbed CAS. If the timing is advanced, you'll get detonation. I would pull the CAS and restab it, then check timing with a light. A Haynes manual has the procedure to do this. Some related info here too: https://www.rx7club.com/showthread.p...light=stab+CAS
The #1 cause for unexplained detonation in an NA is going to be an improperly stabbed CAS. If the timing is advanced, you'll get detonation. I would pull the CAS and restab it, then check timing with a light. A Haynes manual has the procedure to do this. Some related info here too: https://www.rx7club.com/showthread.p...light=stab+CAS
06-28-12, 05:09 PM
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Detonation - Solution
I finally gave in and brought the car to my local Mazda Dealer. They said there was arcing between cables and chassis. They replaced cables and plugs. That fixed the detonation and missing.
They also charged me 160 for diagnostics
90 for a rear alignment
640 Grand total . . . it looks like they charge be about $400 for cables and plugs. Thats what happens when you go to a Mazda/Mazerati dealer.
I declined some other items that would have gotten the bill up to 1360.00.
This car is 24 years and this probably the first time it has has service except for maintainance.
They also charged me 160 for diagnostics
90 for a rear alignment
640 Grand total . . . it looks like they charge be about $400 for cables and plugs. Thats what happens when you go to a Mazda/Mazerati dealer.
I declined some other items that would have gotten the bill up to 1360.00.
This car is 24 years and this probably the first time it has has service except for maintainance.
Last edited by steve3691; 06-28-12 at 05:11 PM.
06-29-12, 02:56 AM
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Expensive lesson.
But you said you owned the car and it had this same problem for 10 years.
This means you never changed the plugs in 10 years?...so where is the Maintenance you speak of?(last sentence).
The car is 24 years old,so it Will require maintenance to keep it running.I hope you do a fuel filter and oil change next.
But you said you owned the car and it had this same problem for 10 years.
This means you never changed the plugs in 10 years?...so where is the Maintenance you speak of?(last sentence).
The car is 24 years old,so it Will require maintenance to keep it running.I hope you do a fuel filter and oil change next.
06-29-12, 12:20 PM
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[QUOTEThe car is 24 years old,so it Will require maintenance to keep it running.I hope you do a fuel filter and oil change next.[/QUOTE]
A bit snarky today ?
The car has been driven 5000 miles in the last 10 years and has had fluids and filters replaced every 500 or 1000 miles. I meant to say there has never been a "problem" requiring service before this detonation issue. The same dealer said they could not find the problem 4 years ago when I brought it in.
A bit snarky today ?
The car has been driven 5000 miles in the last 10 years and has had fluids and filters replaced every 500 or 1000 miles. I meant to say there has never been a "problem" requiring service before this detonation issue. The same dealer said they could not find the problem 4 years ago when I brought it in.
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