red hot cat
04-09-2010, 04:34 PM
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red hot cat
I have a problem!
engine starts, runs bad straight away then gets worse, I think its running on both rotors to start with it also has a bad detonation/rattle/ marbles noise on the over run then after a few minutes drops down onto one rotor.
I bought the car running this way and have no history!
Today I started the engine to warm up to do a compression test,when up to temperature I got under the car to remove the spark plugs and was shocked to see the cat glowing red - more like yellow hot. did the compression test -
rotor 2=123psi rotor 1 = 112
121psi 115
@306 125psi @312 113
rpm rpm
not perfect I know but not too far out!
If it was a piston engine I would say the timing was severely retarded! could this could explain the poor running and bad noise and what could be the cause
Any suggestions??
engine starts, runs bad straight away then gets worse, I think its running on both rotors to start with it also has a bad detonation/rattle/ marbles noise on the over run then after a few minutes drops down onto one rotor.
I bought the car running this way and have no history!
Today I started the engine to warm up to do a compression test,when up to temperature I got under the car to remove the spark plugs and was shocked to see the cat glowing red - more like yellow hot. did the compression test -
rotor 2=123psi rotor 1 = 112
121psi 115
@306 125psi @312 113
rpm rpm
not perfect I know but not too far out!
If it was a piston engine I would say the timing was severely retarded! could this could explain the poor running and bad noise and what could be the cause
Any suggestions??
04-09-2010, 04:36 PM
#2
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the car doesn't "drop down onto one rotor"
your cat is clogged.
remove the 3 bolts connecting it to the exhaust manifold (when it's cold), look inside and you'll quickly know if the cat is damaged.
It sounds like it is and when you're driving, the pieces are bouncing around and that's what you are hearing.
your cat is clogged.
remove the 3 bolts connecting it to the exhaust manifold (when it's cold), look inside and you'll quickly know if the cat is damaged.
It sounds like it is and when you're driving, the pieces are bouncing around and that's what you are hearing.
04-09-2010, 04:38 PM
#3
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before I get flooded with even more PM's asking me, "how will I know if it's broken?!"
that's what my RP high flow cat looked like when it died.
that's what my RP high flow cat looked like when it died.
04-09-2010, 04:48 PM
#6
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can be damaged various ways:
- cat got hit because you hit a speed bump
- flooded engine
- bad coils
tough to tell, no way of really knowing without the entire history of the car.
These cats (with the most recent mazda PCM flash) are designed to last at least 80,000 miles.
how old is your car? miles?
- cat got hit because you hit a speed bump
- flooded engine
- bad coils
tough to tell, no way of really knowing without the entire history of the car.
These cats (with the most recent mazda PCM flash) are designed to last at least 80,000 miles.
how old is your car? miles?
04-09-2010, 04:56 PM
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04 with Only 18,600 miles but it has had front end damage, repaired before I got it so it was probably hanging around for a while. It only has 2 service stamps in the warranty book one at 6500miles the other at 18200miles about a year ago.
04-09-2010, 05:30 PM
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04 with only 18,000 miles?!
where do you live cwumbs? US? (if so, what region?)
cat is under federal warranty still so if it's broken you get a free replacement at the dealership.
warranty book? wha? people actually use that still?
cat sensors? you mean O2 sensors? probably not fried, and there's only one at the cat.
where do you live cwumbs? US? (if so, what region?)
cat is under federal warranty still so if it's broken you get a free replacement at the dealership.
warranty book? wha? people actually use that still?
cat sensors? you mean O2 sensors? probably not fried, and there's only one at the cat.
04-09-2010, 05:42 PM
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I'm in the UK, yes we still use the warranty book, and only get 3 years or 60,000 miles ,whichever comes first, so mines out! The cat was extremely hot! it was as if an oxyacetalene torch had been on it and only seconds from melting!
04-09-2010, 05:48 PM
#11
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our cats get extremely hot due to the fire-breather nature of the rotary engine.
I would drop the cat and have a peak inside to see if there's noticable damage.
I would drop the cat and have a peak inside to see if there's noticable damage.
04-09-2010, 05:49 PM
#12
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all of that missing and stumbling is causing unburned fuel to enter the hot cat and burn in the cat which makes the cat hotter and has possibly melted it it closed or broken it to clog it.
the reason its missing so bad could be any number of reasons from the timing being off because the eshaft profile needing reset to the plug wires not being on well enough to bad coils to fouled plugs etc etc. im sure the plugs are fouled now after what you are describing.
what did the plugs look like when you pulled them?
the reason its missing so bad could be any number of reasons from the timing being off because the eshaft profile needing reset to the plug wires not being on well enough to bad coils to fouled plugs etc etc. im sure the plugs are fouled now after what you are describing.
what did the plugs look like when you pulled them?
04-09-2010, 06:06 PM
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Plugs were a bit sooted up but they are quite new (last owner) tested the plug leads - around 6kohms. coils tested= ab 1.5kohms cb open circuit??? ca open circuit. Is cb open circuit correct? Am going to check timing tommorrow.
04-09-2010, 06:08 PM
#14
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spark plugs: brown is okay, black is bad
you should test the ignition coils and if the wires are old, I'd recommend just replacing them.
ignition coil test: http://www.finishlineperformance.com...16-07-1793.pdf
you should test the ignition coils and if the wires are old, I'd recommend just replacing them.
ignition coil test: http://www.finishlineperformance.com...16-07-1793.pdf
04-09-2010, 06:18 PM
#16
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spots on the back of the coils means nothing.
only way to know is to test them per the instructions I just posted.
only way to know is to test them per the instructions I just posted.
04-09-2010, 07:07 PM
#19
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did you read the whole pdf?
don't start that car to check the timing without checking inside the cat. you could set your car on fire.
and before you check the timing just do the 20 brake stomp reset.
turn the key to on pump the brakes like mad at least 20 times. keep going until you see the oil gauge needle sweep. turn the key off. that resets the memory of the trigger wheel/hall sensor position in the PCM memory.
don't start that car to check the timing without checking inside the cat. you could set your car on fire.
and before you check the timing just do the 20 brake stomp reset.
turn the key to on pump the brakes like mad at least 20 times. keep going until you see the oil gauge needle sweep. turn the key off. that resets the memory of the trigger wheel/hall sensor position in the PCM memory.
04-09-2010, 07:20 PM
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Yes thats why I asked the question about the c-b terminals part of the test being open circuit - am I interpreting it correctly? does this result mean my coils are shot?
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