Engine detonation
#1
Engine detonation
Hi,
I have the bucking/stalling problem. I put a 500kOhm resistor to bypass the knock sensor to see if it could be the cause of this problem. When the resistor is installed, I can hear detonation under load. I removed the resistor and everything is fine. It seems that it is not the source of my issues.
Do you think that a bad O2 sensor or a bad engine temperature sensor could cause the engine to detonate?
I have the bucking/stalling problem. I put a 500kOhm resistor to bypass the knock sensor to see if it could be the cause of this problem. When the resistor is installed, I can hear detonation under load. I removed the resistor and everything is fine. It seems that it is not the source of my issues.
Do you think that a bad O2 sensor or a bad engine temperature sensor could cause the engine to detonate?
#3
Wait, am I not getting something? If you only get detonation with the 500kohm resistor plugged in, bypassing the knock sensor... and when you leave everything stock it's fine... what is the problem?
If you mean it has a bucking/stalling problem otherwise, when the knock sensor isn't being touched... then I agree with mikekantor, though it can also be a Coolant Temperature sensor, that is easy to check and diagnose and is only $30 if that is the problem.
If you mean it has a bucking/stalling problem otherwise, when the knock sensor isn't being touched... then I agree with mikekantor, though it can also be a Coolant Temperature sensor, that is easy to check and diagnose and is only $30 if that is the problem.
Last edited by Pearl93VE; 06-13-2008 at 03:14 PM.
#4
Wait, am I not getting something? If you only get detonation with the 500kohm resistor plugged in, bypassing the knock sensor... and when you leave everything stock it's fine... what is the problem?
If you mean it has a bucking/stalling problem otherwise, when the knock sensor isn't being touched... then I agree with mikekantor, though it can also be a Coolant Temperature sensor, that is easy to check and diagnose and is only $30 if that is the problem.
If you mean it has a bucking/stalling problem otherwise, when the knock sensor isn't being touched... then I agree with mikekantor, though it can also be a Coolant Temperature sensor, that is easy to check and diagnose and is only $30 if that is the problem.
I should change my ignition coils but its kinda expensive so I wanted to see if it could be something else. I don't want to waste my money on this car since it is old and expensive to ride (here it is 5,48$ for 1 gallon of fuel). I hate it, I know that if I spend like 500$ the car would probably run like a new one, but ?$/?/$Q""?/")...
#5
adjust your timing, retard it a bit until it stops detonating with the resistor in.
your knock sensor being bad causes the ignition timing to be retarded into a safe mode, that is why there is no detonation with it connected.
you can also run a higher octane fuel to help matters. these cars are designed to tun on US octane rating 91.
your knock sensor being bad causes the ignition timing to be retarded into a safe mode, that is why there is no detonation with it connected.
you can also run a higher octane fuel to help matters. these cars are designed to tun on US octane rating 91.
#6
adjust your timing, retard it a bit until it stops detonating with the resistor in.
your knock sensor being bad causes the ignition timing to be retarded into a safe mode, that is why there is no detonation with it connected.
you can also run a higher octane fuel to help matters. these cars are designed to tun on US octane rating 91.
your knock sensor being bad causes the ignition timing to be retarded into a safe mode, that is why there is no detonation with it connected.
you can also run a higher octane fuel to help matters. these cars are designed to tun on US octane rating 91.
Well, I will see what I can do, I will change all my ignition coils, change the engine cooling temp sensor and try it again. If it doesn't work, retarding the timing seems to be a good idea.
At least I have another car that I can use while I deal with these problems. But I want to get ride of them as soon as possible.
#8
I just used one of each (front and rear) then swapped them one by one until I found the problem on the bucking/stalling. Mine was a bad rear one.
However detonation (I assume you mean pinging) is usually the sign of a bad knock sensor and also using lower octane gas than you are supposed to. These engines were designed to run on 91+ octane, not 87. A bad KS + low octane might cause your problem.
These are just possibilities, since I am not there in person to help out.
#9
I just used one of each (front and rear) then swapped them one by one until I found the problem on the bucking/stalling. Mine was a bad rear one.
However detonation (I assume you mean pinging) is usually the sign of a bad knock sensor and also using lower octane gas than you are supposed to. These engines were designed to run on 91+ octane, not 87. A bad KS + low octane might cause your problem.
These are just possibilities, since I am not there in person to help out.
With a working KS or funky KS or KS resistor bypass mod, if you have ping at any stage its time to leave any other hassles you have alone and retard the timing (or figure its cause and rectify) .................... NOW!
#10
I am not an expert in detonation and pinging but it sound like sparks or... Well it is difficult to describe. It only happens under load over 3000rpm with the KS bypass. I never run with 87 octane, but it is possible that there is 89 octane right now in the tank, the last time I bought "silver" fuel (the octane level was not indicated) and it may be 89, not 91. I'll check that, It could be part of the problem. I will empty the tank with the KS plugged, anyway it is almost empty and then I'll fill it with 91+. I will try to find 94, it might help.
Last edited by Nyxo-z; 06-14-2008 at 12:13 PM.
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