Regular unleaded gas/ sluggish motor
03-26-2011, 11:05 PM
#21
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"The plugs have probably been trashed from running the lower octane gas, change them."
Why is that? Plugs usually last 100K miles on regular in lots of vehicles using only regular gas. I'd go with putting in premium gas, resetting the ECU, see how it runs, and then take other action as required.
Don't do the compression test until you find out if more work is required. You can do it when you change the plugs, IF you have to change them. If it runs right after the ECU reset, you're good to go.
Why is that? Plugs usually last 100K miles on regular in lots of vehicles using only regular gas. I'd go with putting in premium gas, resetting the ECU, see how it runs, and then take other action as required.
Don't do the compression test until you find out if more work is required. You can do it when you change the plugs, IF you have to change them. If it runs right after the ECU reset, you're good to go.
OP, change the plugs, use premium, rest ECU, and check to make sure the throttle body is opening all the way when at WOT.
03-28-2011, 03:15 PM
#22
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My daughter bought a new Mazda CX-9 V6. The manual said to run premium, but she put in regular to save a few bucks. The cat system failed twice while it was under warranty, and the dealership siad it was the result of running regular fuel The dealership told her it would be $1800 if it went out again after the warranty expired, so she traded it for a Subaru Outback.
03-28-2011, 07:08 PM
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My daughter bought a new Mazda CX-9 V6. The manual said to run premium, but she put in regular to save a few bucks. The cat system failed twice while it was under warranty, and the dealership siad it was the result of running regular fuel The dealership told her it would be $1800 if it went out again after the warranty expired, so she traded it for a Subaru Outback.
03-29-2011, 05:26 AM
#24
My daughter bought a new Mazda CX-9 V6. The manual said to run premium, but she put in regular to save a few bucks. The cat system failed twice while it was under warranty, and the dealership siad it was the result of running regular fuel The dealership told her it would be $1800 if it went out again after the warranty expired, so she traded it for a Subaru Outback.
03-29-2011, 05:38 AM
#25
I just recently purchased an 03 350z 6mt with 70k miles
This is my 3rd 350z, and this one seems to run very sluggish..
The motor sounds fine.. idles perfectly.. no noticeable sounds/shaking at all..
HOWEVER. its SLOWWWW.. very sloww to accelerate.. when im cruising in 2nd gear going 40 and punch it! it is very slow to accelerate.. The rpm's climb slowly and it doesnt have that 'kick' when u got WOT..
If the Previous owner was using regular gas.. did he PERMANENTLY screw up the air/fuel mixture..? Can this be reversed if i started using PRemium fuel only?????
Please advise...
This is my 3rd 350z, and this one seems to run very sluggish..
The motor sounds fine.. idles perfectly.. no noticeable sounds/shaking at all..
HOWEVER. its SLOWWWW.. very sloww to accelerate.. when im cruising in 2nd gear going 40 and punch it! it is very slow to accelerate.. The rpm's climb slowly and it doesnt have that 'kick' when u got WOT..
If the Previous owner was using regular gas.. did he PERMANENTLY screw up the air/fuel mixture..? Can this be reversed if i started using PRemium fuel only?????
Please advise...
04-03-2011, 10:14 AM
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Whenever I buy a used car with basically unknown maintenance history I completely go through it.
New air filters, induction service, fuel injector service, compression check, new plugs, and change all fluids front to back. You could also send out an oil sample to check the internals.
Good luck
New air filters, induction service, fuel injector service, compression check, new plugs, and change all fluids front to back. You could also send out an oil sample to check the internals.
Good luck
04-03-2011, 03:15 PM
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whenever i buy a used car with basically unknown maintenance history i completely go through it.
New air filters, induction service, fuel injector service, compression check, new plugs, and change all fluids front to back. You could also send out an oil sample to check the internals.
Good luck
New air filters, induction service, fuel injector service, compression check, new plugs, and change all fluids front to back. You could also send out an oil sample to check the internals.
Good luck
04-03-2011, 10:23 PM
#28
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The last used vehicle I bought was a six-cylinder '90 Ford pickup with 19K miles on it in '92. I sold it in 2003 with 105K miles on it.
I never touched the drive train except for a fan belt replacement and routine oil and oil filter changes on the engine. When I sold it, the original air filter, radiator coolant, AT fluid, spark plugs, and rear end oil were still in it, and it was running and driving just fine.
I know the fellow I sold it to kept it for several years with no issues, so the truck obviously wasn't dying when I sold it.
Routine maintenance (with the exception of engine oil and filter) is highly overrated, but if it makes you feel good, have at it.
I never touched the drive train except for a fan belt replacement and routine oil and oil filter changes on the engine. When I sold it, the original air filter, radiator coolant, AT fluid, spark plugs, and rear end oil were still in it, and it was running and driving just fine.
I know the fellow I sold it to kept it for several years with no issues, so the truck obviously wasn't dying when I sold it.
Routine maintenance (with the exception of engine oil and filter) is highly overrated, but if it makes you feel good, have at it.
04-04-2011, 01:51 AM
#29
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i reset the ecu and began running premium only.. there is still no difference is performance.. and to add more info.. The motor has a loud and audible ticking sound coming from the top of the motor.. the ticking speeds up as i step on the accelerator.. I fear that the ticking is 'rod knocking' or a stuck lifter...
I was hoping the ticking was because of the grade of gas... but even after running premium its still ticking... any ideas?
I was hoping the ticking was because of the grade of gas... but even after running premium its still ticking... any ideas?
05-03-2012, 08:00 PM
#31
Im about a year late but whatever, Ive been doing my research and what ive understood is that becuase lower octane fuels have more burning resistance the engine thinks its burning when its not. Again im not expert (so if im wrong correct me) thats what i understood. and that the engine will start knocking when too much regular fuel is used. What does that mean? knocking???
05-05-2012, 11:02 AM
#32
Im about a year late but whatever, Ive been doing my research and what ive understood is that becuase lower octane fuels have more burning resistance the engine thinks its burning when its not. Again im not expert (so if im wrong correct me) thats what i understood. and that the engine will start knocking when too much regular fuel is used. What does that mean? knocking???
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