93Rubie
Well-known member
Got kinda of a strange issue on my buddies 94. At idle it has a definite miss, maybe 1 cylinder a most. Checked spark off coil with inline checker=constant spark no dropping out. Checked the easy to get too #4 plug wire=steady and even spark.
Running down the road, runs ok at a cruise, WOT, lighter loads. However, if you gently apply throttle as to not get it out of overdrive but still increase the load the car starts to knock, hard metallic knocks. Definlety "pinging" in the old fashioned detention sense. The knock sensors go nuts and pulls 20 degrees right now. However, it is a on/off switch it is either pinging or not. The knock counts go from 1 or 2 to a bunch really quick and then back, when I let off or force a downshift.
For some reason I cannot see High Resolution signal on my scan tool I can on my 93 but not his 94. IDK? Anyhow I can see the low resolution signal and it kinda bounces around at idle. With a warm idle it can bounce around from about 22m/sec to 24/25m/sec. Never noticed my 93 doing this. I did back probe the Opti-Spark connection and at idle, warm low resolution bounces from about .9V to 1.2V. High is even at about 2.4V. Not sure if this is normal or not FSM doesn't really give me the info I want on this one.
Idle timing on scan tool reads about 20 degrees cold/17 or so warm. That seems to be ok.
No CODES in ECM. I did have a 54 and 41 in the CCM as history codes.
Today, after messing with some other things I was spraying down the wiring, just checking, and noticed the number 5 cylinder plug wire seemed to be moving?!?! Sure as pie, the #5 plug was loose. Tightened it up, still had the miss at idle. SOB!!! Plug appeared to have been firing,not wet or fouled. (I pulled it.)
FYI, this car is in sad shape, previous owners ran it hard and put it away wet. The current owner is not much better with it. I see the car when it starts to run not just bad but REALLY bad. Needless to say, its a basket case, you fix one issue, be prepared to fix some more. That and others have really boogered this thing but with backyard HACK fixes, its a nightmare.
Anyone have ideas? My current thoughts are these:
Check all plugs on bank 1 (bank 1 has larger pulse width than bank 2) make sure they all have spark/tight. Then check bank 2 for the same. Pending that is ok, why is the opti-spark low resolution readings jumping around everywhere, just because of the miss, is my guess??? Them moving like that strikes me as odd.
Oh, I did check grounds, tight and reasonably clean.
As usual this started as a no start, died in the rain on him event. :eyerole Turned out battery was just shot. New(er) battery it fired right up but missing.
Running down the road, runs ok at a cruise, WOT, lighter loads. However, if you gently apply throttle as to not get it out of overdrive but still increase the load the car starts to knock, hard metallic knocks. Definlety "pinging" in the old fashioned detention sense. The knock sensors go nuts and pulls 20 degrees right now. However, it is a on/off switch it is either pinging or not. The knock counts go from 1 or 2 to a bunch really quick and then back, when I let off or force a downshift.
For some reason I cannot see High Resolution signal on my scan tool I can on my 93 but not his 94. IDK? Anyhow I can see the low resolution signal and it kinda bounces around at idle. With a warm idle it can bounce around from about 22m/sec to 24/25m/sec. Never noticed my 93 doing this. I did back probe the Opti-Spark connection and at idle, warm low resolution bounces from about .9V to 1.2V. High is even at about 2.4V. Not sure if this is normal or not FSM doesn't really give me the info I want on this one.
Idle timing on scan tool reads about 20 degrees cold/17 or so warm. That seems to be ok.
No CODES in ECM. I did have a 54 and 41 in the CCM as history codes.
Today, after messing with some other things I was spraying down the wiring, just checking, and noticed the number 5 cylinder plug wire seemed to be moving?!?! Sure as pie, the #5 plug was loose. Tightened it up, still had the miss at idle. SOB!!! Plug appeared to have been firing,not wet or fouled. (I pulled it.)
FYI, this car is in sad shape, previous owners ran it hard and put it away wet. The current owner is not much better with it. I see the car when it starts to run not just bad but REALLY bad. Needless to say, its a basket case, you fix one issue, be prepared to fix some more. That and others have really boogered this thing but with backyard HACK fixes, its a nightmare.
Anyone have ideas? My current thoughts are these:
Check all plugs on bank 1 (bank 1 has larger pulse width than bank 2) make sure they all have spark/tight. Then check bank 2 for the same. Pending that is ok, why is the opti-spark low resolution readings jumping around everywhere, just because of the miss, is my guess??? Them moving like that strikes me as odd.
Oh, I did check grounds, tight and reasonably clean.
As usual this started as a no start, died in the rain on him event. :eyerole Turned out battery was just shot. New(er) battery it fired right up but missing.