Just bought RX8 NEED HELP!
03-13-2014, 06:52 PM
#26
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Sigh.
Starting up after waiting a bit could point to a fuel pump issue or nothing at all.
Yes, a fine cold start but hard hot start generally points to low compression, failing fuel pump, or a fuel line pressure problem.
Driving on regular is dangerous to your engine if even 1 of the 6 rotor faces has healthy compression. Regular is only safe if your engine is failing on all 6 rotor faces. You need to use 89 octane at a minimum, 91 or 93 is far far far far far better, especially on hot days. Yes, you can blow your engine on 89 octane. Keep the revs down and don't go full throttle until you can fill back up with high octane.
Again, all of this is in the new owner's thread. Have you even opened it yet?
Starting up after waiting a bit could point to a fuel pump issue or nothing at all.
Yes, a fine cold start but hard hot start generally points to low compression, failing fuel pump, or a fuel line pressure problem.
Driving on regular is dangerous to your engine if even 1 of the 6 rotor faces has healthy compression. Regular is only safe if your engine is failing on all 6 rotor faces. You need to use 89 octane at a minimum, 91 or 93 is far far far far far better, especially on hot days. Yes, you can blow your engine on 89 octane. Keep the revs down and don't go full throttle until you can fill back up with high octane.
Again, all of this is in the new owner's thread. Have you even opened it yet?
03-13-2014, 06:55 PM
#27
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https://www.rx8club.com/new-member-f...4/#post4533733
https://www.rx8club.com/new-member-f...4/#post4533735
So I need a compression test right? (Updated November 14th 2013)
Yes. And it can not be done with a standard analog compression tester for piston engines. A typical cheap analog tester just plugs into a spark plug port and as the engine cranks, the needle moves, and you can easily see where it's swinging to every compression stroke. 1 spark plug, 1 cylinder, 1 compression number.
The rotary however is 1 spark plug, 3 rotor cavities, 3 compression numbers per revolution. There is no way for a simple analog tester to record each face of the rotor independently as it spins, updating each number correctly as it compresses.
Piston engines also have relatively the same compression number regardless of how fast the engine is pumping. If there is a loss of compression due to a seal or whatever, there will be some loss as it compresses, and a slower RPM will read slightly less as it allows slightly more time to leak. Rotary engines have plenty of 'gaps', and there is a very real and measurable difference in compression depending on engine cranking speed. The faster it spins the higher the compression. You can even remove the apex seals completely, and it gets enough compression at 9,000rpm to stay alive, though not much below that it won't. (incidentally, this is an often over-looked dynamic of how the engine produces it's power curve, and how it doesn't have severe drop-off in power the higher you go in RPM the way piston engines do, and one of the reasons low rpm torque is so poor. Not the only reason, but a contributing factor). So, in addition to the 2 sets of 3 numbers for each of the 3 faces of each of the 2 rotors, you need the crank RPM for the test. A normalization chart based on RPM determines if you are pass or fail.
Many dealers also obtain a BARO voltage reading test to determine vacuum as another method of determining pass or fail. Vacuum is related to compression, but it isn't the same thing, and is possible for them to differ more than expected. There have been quite a few reports of Mazda techs returning BARO numbers that clearly fail and stating that they pass, so if it fails compression but passes vacuum, I'd question the techs quite a bit about making sure they did it right.
Only Mazda dealers will be able to do a compression test, unless you happen to live near one of the bare handful of non-Mazda owned rotary compression testers.
Your best bet is to simply ask the dealer if you can take it to get a compression test. If they decline, they ask if they can do it. If they still decline, then they probably have something to hide and you should immediately cross that 8 off your list, no matter how much surface appeal it has.
No reputable dealer will object to having one of their cars checked over by a 3rd party, ESPECIALLY when it's a particular check that only Mazda dealers can do. A129 million point inspection means nothing if they don't have a rotary compression tester to check the most critical part. Or convince them to cover the engine with an extended warranty on THEIR dime. "Hey, if you can't check the engine, I'm taking a risk buying it, and you need to cover it in case I'm buying a time bomb."
Yes. And it can not be done with a standard analog compression tester for piston engines. A typical cheap analog tester just plugs into a spark plug port and as the engine cranks, the needle moves, and you can easily see where it's swinging to every compression stroke. 1 spark plug, 1 cylinder, 1 compression number.
The rotary however is 1 spark plug, 3 rotor cavities, 3 compression numbers per revolution. There is no way for a simple analog tester to record each face of the rotor independently as it spins, updating each number correctly as it compresses.
Piston engines also have relatively the same compression number regardless of how fast the engine is pumping. If there is a loss of compression due to a seal or whatever, there will be some loss as it compresses, and a slower RPM will read slightly less as it allows slightly more time to leak. Rotary engines have plenty of 'gaps', and there is a very real and measurable difference in compression depending on engine cranking speed. The faster it spins the higher the compression. You can even remove the apex seals completely, and it gets enough compression at 9,000rpm to stay alive, though not much below that it won't. (incidentally, this is an often over-looked dynamic of how the engine produces it's power curve, and how it doesn't have severe drop-off in power the higher you go in RPM the way piston engines do, and one of the reasons low rpm torque is so poor. Not the only reason, but a contributing factor). So, in addition to the 2 sets of 3 numbers for each of the 3 faces of each of the 2 rotors, you need the crank RPM for the test. A normalization chart based on RPM determines if you are pass or fail.
Many dealers also obtain a BARO voltage reading test to determine vacuum as another method of determining pass or fail. Vacuum is related to compression, but it isn't the same thing, and is possible for them to differ more than expected. There have been quite a few reports of Mazda techs returning BARO numbers that clearly fail and stating that they pass, so if it fails compression but passes vacuum, I'd question the techs quite a bit about making sure they did it right.
Originally Posted by omgitsdomie
1. While i've been searching around for rx8's there are some at different dealers. EX: an rx8 at a Nissan dealer. How would you go about asking to get a compression test since usually most dealers wont let you take a car somewhere without a representative, and usually they only go with you only for test drives, and test drives only?
Your best bet is to simply ask the dealer if you can take it to get a compression test. If they decline, they ask if they can do it. If they still decline, then they probably have something to hide and you should immediately cross that 8 off your list, no matter how much surface appeal it has.
No reputable dealer will object to having one of their cars checked over by a 3rd party, ESPECIALLY when it's a particular check that only Mazda dealers can do. A129 million point inspection means nothing if they don't have a rotary compression tester to check the most critical part. Or convince them to cover the engine with an extended warranty on THEIR dime. "Hey, if you can't check the engine, I'm taking a risk buying it, and you need to cover it in case I'm buying a time bomb."
I am buying it! What should I address first? (Updated October 25th 2013)
Generally, the more history on these items you can get from the prior owner, the better. These are all RX-8 specific. They are in addition to typical items like brakes and tires. Every item on this list is on it because it either fails regularly OR a failure of the point will result in significant cascading damage and costly repairs.
This is also the long term recommended maintenance list from us here on RX8Club.com.
Car mileage over 30,000:
- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.
Car mileage over 60,000:
...all above, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.
Car mileage over 90,000:
...all above plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.
Obviously if you get information about any of these items already addressed, it will help to reduce the list / cost. Get as much certainty as you can though! All cooling related items can cost you your engine! Even as soon as the same day you take the 8 home with you. It has happened more than once. The rest can be just as critical in how much it can cost you.
Note: This isn't a dealer's maintenance list that is filled with questionable fluff. Every single one of these items is something that typically fails in that mileage range, and for each item, if it fails it will either A) strand you, or B) cause significant and costly additional damage.
Generally, the more history on these items you can get from the prior owner, the better. These are all RX-8 specific. They are in addition to typical items like brakes and tires. Every item on this list is on it because it either fails regularly OR a failure of the point will result in significant cascading damage and costly repairs.
This is also the long term recommended maintenance list from us here on RX8Club.com.
Car mileage over 30,000:
- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.
Car mileage over 60,000:
...all above, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.
Car mileage over 90,000:
...all above plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.
Obviously if you get information about any of these items already addressed, it will help to reduce the list / cost. Get as much certainty as you can though! All cooling related items can cost you your engine! Even as soon as the same day you take the 8 home with you. It has happened more than once. The rest can be just as critical in how much it can cost you.
Note: This isn't a dealer's maintenance list that is filled with questionable fluff. Every single one of these items is something that typically fails in that mileage range, and for each item, if it fails it will either A) strand you, or B) cause significant and costly additional damage.
03-13-2014, 06:58 PM
#28
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yes I have lol....Im more concerned with this thread and figuring out what went wrong with my car. So I go get a compression test done at mazda..... if thats fine then go with the fuel pump/pressure assumption?
03-13-2014, 07:00 PM
#29
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My post was answering yours. I'm just going to keep quoting sections of the thread that answer your questions
https://www.rx8club.com/new-member-f...4/#post4533733
https://www.rx8club.com/new-member-f...4/#post4533735
https://www.rx8club.com/new-member-f...4/#post4533733
So I need a compression test right? (Updated November 14th 2013)
Yes. And it can not be done with a standard analog compression tester for piston engines. A typical cheap analog tester just plugs into a spark plug port and as the engine cranks, the needle moves, and you can easily see where it's swinging to every compression stroke. 1 spark plug, 1 cylinder, 1 compression number.
The rotary however is 1 spark plug, 3 rotor cavities, 3 compression numbers per revolution. There is no way for a simple analog tester to record each face of the rotor independently as it spins, updating each number correctly as it compresses.
Piston engines also have relatively the same compression number regardless of how fast the engine is pumping. If there is a loss of compression due to a seal or whatever, there will be some loss as it compresses, and a slower RPM will read slightly less as it allows slightly more time to leak. Rotary engines have plenty of 'gaps', and there is a very real and measurable difference in compression depending on engine cranking speed. The faster it spins the higher the compression. You can even remove the apex seals completely, and it gets enough compression at 9,000rpm to stay alive, though not much below that it won't. (incidentally, this is an often over-looked dynamic of how the engine produces it's power curve, and how it doesn't have severe drop-off in power the higher you go in RPM the way piston engines do, and one of the reasons low rpm torque is so poor. Not the only reason, but a contributing factor). So, in addition to the 2 sets of 3 numbers for each of the 3 faces of each of the 2 rotors, you need the crank RPM for the test. A normalization chart based on RPM determines if you are pass or fail.
Many dealers also obtain a BARO voltage reading test to determine vacuum as another method of determining pass or fail. Vacuum is related to compression, but it isn't the same thing, and is possible for them to differ more than expected. There have been quite a few reports of Mazda techs returning BARO numbers that clearly fail and stating that they pass, so if it fails compression but passes vacuum, I'd question the techs quite a bit about making sure they did it right.
Only Mazda dealers will be able to do a compression test, unless you happen to live near one of the bare handful of non-Mazda owned rotary compression testers.
Your best bet is to simply ask the dealer if you can take it to get a compression test. If they decline, they ask if they can do it. If they still decline, then they probably have something to hide and you should immediately cross that 8 off your list, no matter how much surface appeal it has.
No reputable dealer will object to having one of their cars checked over by a 3rd party, ESPECIALLY when it's a particular check that only Mazda dealers can do. A129 million point inspection means nothing if they don't have a rotary compression tester to check the most critical part. Or convince them to cover the engine with an extended warranty on THEIR dime. "Hey, if you can't check the engine, I'm taking a risk buying it, and you need to cover it in case I'm buying a time bomb."
Yes. And it can not be done with a standard analog compression tester for piston engines. A typical cheap analog tester just plugs into a spark plug port and as the engine cranks, the needle moves, and you can easily see where it's swinging to every compression stroke. 1 spark plug, 1 cylinder, 1 compression number.
The rotary however is 1 spark plug, 3 rotor cavities, 3 compression numbers per revolution. There is no way for a simple analog tester to record each face of the rotor independently as it spins, updating each number correctly as it compresses.
Piston engines also have relatively the same compression number regardless of how fast the engine is pumping. If there is a loss of compression due to a seal or whatever, there will be some loss as it compresses, and a slower RPM will read slightly less as it allows slightly more time to leak. Rotary engines have plenty of 'gaps', and there is a very real and measurable difference in compression depending on engine cranking speed. The faster it spins the higher the compression. You can even remove the apex seals completely, and it gets enough compression at 9,000rpm to stay alive, though not much below that it won't. (incidentally, this is an often over-looked dynamic of how the engine produces it's power curve, and how it doesn't have severe drop-off in power the higher you go in RPM the way piston engines do, and one of the reasons low rpm torque is so poor. Not the only reason, but a contributing factor). So, in addition to the 2 sets of 3 numbers for each of the 3 faces of each of the 2 rotors, you need the crank RPM for the test. A normalization chart based on RPM determines if you are pass or fail.
Many dealers also obtain a BARO voltage reading test to determine vacuum as another method of determining pass or fail. Vacuum is related to compression, but it isn't the same thing, and is possible for them to differ more than expected. There have been quite a few reports of Mazda techs returning BARO numbers that clearly fail and stating that they pass, so if it fails compression but passes vacuum, I'd question the techs quite a bit about making sure they did it right.
Originally Posted by omgitsdomie
1. While i've been searching around for rx8's there are some at different dealers. EX: an rx8 at a Nissan dealer. How would you go about asking to get a compression test since usually most dealers wont let you take a car somewhere without a representative, and usually they only go with you only for test drives, and test drives only?
Your best bet is to simply ask the dealer if you can take it to get a compression test. If they decline, they ask if they can do it. If they still decline, then they probably have something to hide and you should immediately cross that 8 off your list, no matter how much surface appeal it has.
No reputable dealer will object to having one of their cars checked over by a 3rd party, ESPECIALLY when it's a particular check that only Mazda dealers can do. A129 million point inspection means nothing if they don't have a rotary compression tester to check the most critical part. Or convince them to cover the engine with an extended warranty on THEIR dime. "Hey, if you can't check the engine, I'm taking a risk buying it, and you need to cover it in case I'm buying a time bomb."
I am buying it! What should I address first? (Updated October 25th 2013)
Generally, the more history on these items you can get from the prior owner, the better. These are all RX-8 specific. They are in addition to typical items like brakes and tires. Every item on this list is on it because it either fails regularly OR a failure of the point will result in significant cascading damage and costly repairs.
This is also the long term recommended maintenance list from us here on RX8Club.com.
Car mileage over 30,000:
- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.
Car mileage over 60,000:
...all above, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.
Car mileage over 90,000:
...all above plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.
Obviously if you get information about any of these items already addressed, it will help to reduce the list / cost. Get as much certainty as you can though! All cooling related items can cost you your engine! Even as soon as the same day you take the 8 home with you. It has happened more than once. The rest can be just as critical in how much it can cost you.
Note: This isn't a dealer's maintenance list that is filled with questionable fluff. Every single one of these items is something that typically fails in that mileage range, and for each item, if it fails it will either A) strand you, or B) cause significant and costly additional damage.
Generally, the more history on these items you can get from the prior owner, the better. These are all RX-8 specific. They are in addition to typical items like brakes and tires. Every item on this list is on it because it either fails regularly OR a failure of the point will result in significant cascading damage and costly repairs.
This is also the long term recommended maintenance list from us here on RX8Club.com.
Car mileage over 30,000:
- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.
Car mileage over 60,000:
...all above, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.
Car mileage over 90,000:
...all above plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.
Obviously if you get information about any of these items already addressed, it will help to reduce the list / cost. Get as much certainty as you can though! All cooling related items can cost you your engine! Even as soon as the same day you take the 8 home with you. It has happened more than once. The rest can be just as critical in how much it can cost you.
Note: This isn't a dealer's maintenance list that is filled with questionable fluff. Every single one of these items is something that typically fails in that mileage range, and for each item, if it fails it will either A) strand you, or B) cause significant and costly additional damage.
03-13-2014, 07:36 PM
#31
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Oh **** i forgot! We turned the car off to get gas and then turned it on right after and she started up fine! Thinking it was just a flood ...ill know after test is done tomo
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