Sidekick runs on three cylinders

Do you have any codes?

@saturntech9 Yes, I have a code for the upstream O2 Sensor, that code has been there for over a year now. This problem just started up yesterday while driving, instantaneous.

Mike

Do you know which cylinder it is?I would check spark on the missing cylinder and then compression on all the cylinders if the spark is good.

Hi Saturn
Thanks for the reply, just not sure where you are going with the compression test as the motor runs smoothly for the first minute, then slight miss here and there for maybe fifteen to twenty seconds, then just three cylinders.
regads
Mike

Ok did not get the runs good at first you said suddenly it was running on 3 cylinders.So do you know which cylinder it is not running?If so does it loose spark on that cylinder?

I don't know which cylinder is acting up. What could cause the spark to diminish or cease after running for nearly a minute? Of course I have had plugs just go, but can one actually functon intermitantly? BTW, thank you for your replies.

regards
Mike

You could have spark loss from a coil heating up and failing.Let it idle and miss pull a spark plug ire loose and see if it runs worse and looses rpms.Put the wire back on and go to that next cylinder till you find the cylinders that are not firing.

Okay Saturn, I will be on that in the morning and will let you know.

regards
Mike

Saturn, not sure if you caught it, but the engine seems to fire and run well when the rpms are increased.

regards
Mike

I got that part even if your dropping a cylinder its going to be felt a lot more at idle.Then at higher rpms it can feel like its smooth out.I have seen that before also have seen that when cam timing is off it actual will smooth out at higher rpms.

Saturn, I put in a new timing belt and tensioner at 60,000 miles. If by chance the cam timing is now off, how could it get off? Maybe I'm getting ahead of myself and should just wait until tomorrow and check the cyliners for spark as you have suggested.

regards
Mike

Lets check what i asked and go from there.

Saturn, I pulled the plug wires off the distributor one at a time and each one had had excellent spark. I put in new sparkplugs. I took off the distributor cap to see how it and the rotor were. There appeared to be a little melted hole on the inside top of the cap, along the pathway that the current goes to feed the rotor. I purchased a new cap and rotor from the Suzuki dealer thinking that might be the cause, no luck there. It puzzles me, I can start it cold, runs fine for a minute then misses. I can shut it off and restart it and it runs fine for another twenty seconds or so, shut off and restart, the same, runs for a twenty more seconds then misses again. I did not notice anything unusual on any given cyliner when the wire was take off at the dist cap...in other words it almost seemed like random misses, on maybe each cylinder. The number two spark plug had a very darkened plug compared to the others, but that may or may not be related. Tell me what you think.

regards
Mike

Is the number 2 spark plug really black?Is so that means the number 2 spark plugs is running rich.So does the engine totally clear up missing etc at higher rpms.So when you pulled the wires off one at a time the rpms dropped and you could tell all the cylinders were firing good?

Number 2 cylinder is not extremely black, but dark compared to the others. Yes, all cylinders seemed to be firing okay, but rpms dropped when wire disconnected. I do have some top end clatter and wondered if maybe one of the valves for #2 is in need of adjustment.

regards
Mike

Could be if your getting valve clatter.

I'm starting to think it might be the upstream O2 sensor, maybe it just went dead? The clatter has been there since day one, they are noted for noisey top ends

What is the exact code number you have from the o2 sensor?It will be a P followed by a four digit number.

I purchased a new O2 sensor and just before I installed it I went in to wipe out the code and a new code came up - P0302 missfire on cyl 2. I went ahead and installed the new sensor, started it up and it still misses as before. No loss, the sensor needed to be replaced anyway. Now I guess I have to go through the process of elimination and find out what is wrong. I have installed new plugs, rotor, cap. The #2 spark plug that I took out was much darker than the others, obvious observation confirming a missfire. I have had top end noise since the day I bought it, just hoping it is not a valve, piston ring etc. I was going to go out and purchase a new set of wires, then go from there. What is your take?

Yeah i was going to ask you how the wires look?But you already beat me to it.