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?

 

Probably an injector issue, or an ignition coil issue if you have the VE engine. Whats the year and trim of your car?

 

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.

 

Well my knock sensor is bad even if it still prevent my engine from detonation. When the engine gets hot, the sluggish engine shows up... You probably know what I mean!

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""?/")...

 

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.

 

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.

 

So you have a VE then?

When it buckles/stalls, unplug the coils one by one to find which one or several are the actual bad ones, no need to change all at once.

 

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.

 

+2 ......... maybe.

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!

 

Yes I have a VE. I already tried this method, but I couldn't notice a difference between any of them. I just bought a used set from a guy in this forum so I should be able to get rid of this problem as soon as I receive it. Althought, there is something wierd with the KS bypass. When the KS is unplugged OR plugged, the engine is not pinging under load. When the resistors are in there to bypass the KS, I can hear pinging. (Well I guess it is pinging as you said)

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.

 

Are your injectors in spec? You need a multimeter or ohmmeter to test them.