Mis-Fire...
04-15-2014, 01:52 PM
#1
Mis-Fire... Got a problem after I removed my engine and swapped my oil pan. All went well with the exception of that I damaged the Cam Position Sensor as it got hung up as the engine was being pulled out. I fixed the connector and wire and checked all the way back to the PCM Connector. Should be ok (hope so?).
It started up ok, warmed up ok.. then drove some and then it started to happened. A mis-fire, like once in a while, Not constant but every once in a while or one or two.. then nothing for a bit. Seems to only happen when at running temp.
I swapped out the Cam sender.. no change, still there. Changed out the coil pack, no change again. Thinking it might be the Crank sender as it might have gotten wet while I was cleaning the engine up before it reinstalled everything.
check all of the grounds and they were connected and tight to the block, frame and body. Checked all of the connectors (injector, coil, TPS, ECT, etc...) Couldn't find anything.
No DTC codes being stored !
I connected my monitor and watch the O2 info and fuel trims. A bit funny reading. But then might have always been a bit off balanced between sides.
Anyway..
Voltage is constant on bank 2 at 0.4 at idle and high idle. Bank 1 varies between 0.1 and 0.8
Short Term fuel trim and Fuel trim on bank 2 stand fairly constant 0.0 - 0.8 with Bank 1 jumping up and down at the O2 voltage changes up to 2 or 3 percentage.
Long Term Fuel trim is around 0.8 on Bank 2 with Bank 1 at 12.5 to 14.8. Large difference.
I am looking for input on possible direction to keep looking. Also hear something funny when listening to the exhaust on the Left side (bank 1).. some slight pinging !? but not on the Right Side (bank 2). I also suspect that the problem is on the left side/bank1 as when I am listening to the engine (inside the engine bay). I hear the pop of the mis-fire and think I hear it from the rear of bank 1 (#7 and #5 ?), But that could just be the sound traveling out and down the headers.
Change Bank 2 O2 ?
Change Crank position Sender ?
Any suggestion on other things to try and isolate ?
thanks
BC
It started up ok, warmed up ok.. then drove some and then it started to happened. A mis-fire, like once in a while, Not constant but every once in a while or one or two.. then nothing for a bit. Seems to only happen when at running temp.
I swapped out the Cam sender.. no change, still there. Changed out the coil pack, no change again. Thinking it might be the Crank sender as it might have gotten wet while I was cleaning the engine up before it reinstalled everything.
check all of the grounds and they were connected and tight to the block, frame and body. Checked all of the connectors (injector, coil, TPS, ECT, etc...) Couldn't find anything.
No DTC codes being stored !
I connected my monitor and watch the O2 info and fuel trims. A bit funny reading. But then might have always been a bit off balanced between sides.
Anyway..
Voltage is constant on bank 2 at 0.4 at idle and high idle. Bank 1 varies between 0.1 and 0.8
Short Term fuel trim and Fuel trim on bank 2 stand fairly constant 0.0 - 0.8 with Bank 1 jumping up and down at the O2 voltage changes up to 2 or 3 percentage.
Long Term Fuel trim is around 0.8 on Bank 2 with Bank 1 at 12.5 to 14.8. Large difference.
I am looking for input on possible direction to keep looking. Also hear something funny when listening to the exhaust on the Left side (bank 1).. some slight pinging !? but not on the Right Side (bank 2). I also suspect that the problem is on the left side/bank1 as when I am listening to the engine (inside the engine bay). I hear the pop of the mis-fire and think I hear it from the rear of bank 1 (#7 and #5 ?), But that could just be the sound traveling out and down the headers.
Change Bank 2 O2 ?
Change Crank position Sender ?
Any suggestion on other things to try and isolate ?
thanks
BC
04-15-2014, 02:18 PM
#2
When you repaired the connector, did you solder and heat shrink or use crimp connectors? I've had terrible luck with crimp connectors when I was young and an old timer I used to know taught me to solder 20 years ago and I haven't looked back.
I had an odd misfire in my WS6 that ended up being a bad PCM. Mine would give me a code that said "Cylinder 5 Misfire," but only intermittently.
Essentially there was no spark on cylinder 5 most of the time. I flashed my current tune on a spare PCM and installed it in the car - problem sorted. I moved the PCM to another car and the intermittent misfire followed. Ironically the WS6 was completely stock at the time.
I have HP Tuners which includes an awesome scan / logging utility that helped me find the problem and flash the spare PCM. I think I would have spent a lot of time if I didn't have the real time scan feature.
Just ideas for you. Good luck.
I had an odd misfire in my WS6 that ended up being a bad PCM. Mine would give me a code that said "Cylinder 5 Misfire," but only intermittently.
Essentially there was no spark on cylinder 5 most of the time. I flashed my current tune on a spare PCM and installed it in the car - problem sorted. I moved the PCM to another car and the intermittent misfire followed. Ironically the WS6 was completely stock at the time. I have HP Tuners which includes an awesome scan / logging utility that helped me find the problem and flash the spare PCM. I think I would have spent a lot of time if I didn't have the real time scan feature.
Just ideas for you. Good luck.
04-15-2014, 02:34 PM
#3
I just fixed a misfire issue in my Tacoma truck. Idled kind of rough and eventually would shake like crazy. When this happened the cel light would blink indicating a lean misfire. Just like you no stored codes. Ended up pulling the intake cleaning the whole 9 yards including the injectors and reinstalled with new gaskets and fuel injector O rings. Fixed it right up.
So don't forget the basics, like a loose hose or connector, vac leak, stuck or dirty injector-throttle body-IAC valve, low fuel pressure, dirty fuel filter. Couldn't hurt to pull your plugs and clean them if needed.
As for the cam sensor, if the stock computer is anything like the ignition controller for carbd vehicles than the cam position sensor isn't needed once the car is running. It merely sets the phase at start up. You can usually unplug them once running.
So don't forget the basics, like a loose hose or connector, vac leak, stuck or dirty injector-throttle body-IAC valve, low fuel pressure, dirty fuel filter. Couldn't hurt to pull your plugs and clean them if needed.
As for the cam sensor, if the stock computer is anything like the ignition controller for carbd vehicles than the cam position sensor isn't needed once the car is running. It merely sets the phase at start up. You can usually unplug them once running.
04-15-2014, 04:29 PM
#4
TECH Fanatic
I have seen a code P0461 pop up once in awhile since I updated my PCM, but the code went away after I solved the DBW/pedal mystery. I also have a fuel pump that has finally failed and while trying to get the pump to run so I could get out of the middle of the road the P0461 popped up again. I can't tell right now if the 2 are related or not until I get a replacement fuel pump.
Good luck on this one, I hate electrical gremlins. Let us know what you ultimately find out.
Good luck on this one, I hate electrical gremlins. Let us know what you ultimately find out.
04-15-2014, 08:52 PM
#6
When you pulled the engine out you may have damaged a spark plug wire or boot, possibly cracked a spark plug? In the day when I was a heavy equipment tech, my company would send me to a certain company's job site where they had a in house mechanic, and I dreaded going there because there in house mechanic was a very good mechanic, and I knew if he hadn't been able to figure it out, then it was a real head scratcher problem, or something ridiculously simple. I think that's where we are on your problem, because I have read your posts and threads and it certainly looks like you know your stuff. So for you to ask for help it is either a real head scratcher or something very simple. Either way good luck. KISS
04-15-2014, 10:11 PM
#7
Thanks.. more information on what has been done so far.
- Fuel pressure is good at both idle and high idle, throttle being varied to high and low throttle quickly. Can do a WOT during the drive test (as long as it doesn't mis-fire).
New plugs
- Connector was crimped with new terminal, no extra wire was needed so no soldering involved. Checked with a DVM from connector to PCM Connector.
- Coil pack was swapped with plug wires
- Checked for vacuum leaks
- Intake gaskets and Injector O-Rings (injectors were not removed from the intake/rail) are good, was replaced a little over a year ago the last time I changed the oil pan out.
- checked under the valve cover for any broke spring or loose rockers.
Like you all said and suggested. I have done the basic a few times.. but without a good high end scanner, I will not be able to get a good deep scan. I do know I am not getting any codes.
Looking for more suggestion.. I might have to take it to a shop ??
thanks guys..
BC
- Fuel pressure is good at both idle and high idle, throttle being varied to high and low throttle quickly. Can do a WOT during the drive test (as long as it doesn't mis-fire).
New plugs
- Connector was crimped with new terminal, no extra wire was needed so no soldering involved. Checked with a DVM from connector to PCM Connector.
- Coil pack was swapped with plug wires
- Checked for vacuum leaks
- Intake gaskets and Injector O-Rings (injectors were not removed from the intake/rail) are good, was replaced a little over a year ago the last time I changed the oil pan out.
- checked under the valve cover for any broke spring or loose rockers.
Like you all said and suggested. I have done the basic a few times.. but without a good high end scanner, I will not be able to get a good deep scan. I do know I am not getting any codes.
Looking for more suggestion.. I might have to take it to a shop ??
thanks guys..
BC
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04-16-2014, 10:21 AM
#10
TECH Enthusiast
Brian,
Check your O2 sensor on bank 2 it sounds like it is bad or your ground is bad. An easy check would be to swap O2 sensors and see if the problem swaps sides.
Check your O2 sensor on bank 2 it sounds like it is bad or your ground is bad. An easy check would be to swap O2 sensors and see if the problem swaps sides.
04-16-2014, 10:27 AM
#11
Already using Torque Plus App and a ODBII wireless adapter.
Using MAF, will check it again and spay clean with MAF Cleaner. Might also try disconnecting it once it warms up to see what happens.
O2, I'll try swapping them over or with some spares. As I originally posted, the reading between Bank 1 and 2 were way different.
Thanks guys
BC
Using MAF, will check it again and spay clean with MAF Cleaner. Might also try disconnecting it once it warms up to see what happens.
O2, I'll try swapping them over or with some spares. As I originally posted, the reading between Bank 1 and 2 were way different.
Thanks guys
BC
04-16-2014, 11:17 AM
#12
TECH Enthusiast
I doubt very seriously it is a MAF problem since it is a bank problem. A quicker check is to start it up cold and see if it is running fine and the banks are close. If it goes wacky when it goes closed loop it is either the O2 or a bad leak on that side.
04-16-2014, 12:57 PM
#13
Looks like the problem is on the Bank 1 side, that's why you LTFT are high. Something is telling the computer that you are lean on that side. Swap the O2's side to side just to eliminate that. If that isn't the problem, I would make sure my Bank 1 injectors are firing correctly. If the wiring is correct, then I would swap the injectors side to side to make sure you don't have an injector problem.
Before you do all that, did you a crank relearn after you put the new camshaft sensor in?
http://www.hptuners.com/forum/showth...=crank+relearn
Before you do all that, did you a crank relearn after you put the new camshaft sensor in?
http://www.hptuners.com/forum/showth...=crank+relearn
04-17-2014, 03:27 PM
#15
Update Ok. .swapped the O2 across.. Still getting the same reading..?...
One think I was a little alarmed about was the Bank 2 voltage.. it was at 0.4 steady.. found I had used the PID for the Display. After correcting it. Found that the Voltage was moving as it should like Bank 1 now.
What is still alarming.. is the higher LTFT on Bank 1.. it at times is still 14.8 %.. as compared to Bank 2 which at a much lower percentage.
I have been listening to the popping sound from the tail pipe. The popping is coming from the Bank 1 side..I am wondering if I have a valve problem ? I don't hear any ticking at the engine so maybe it is a burn valve ? Well take the valve cover off again Friday if I have time. Also might try a leak down test to see what the seal is on the valve and rings.
Will keep trying to isolate the problem. But any input on anything would be helpful from you guys.. thanks..
BC
One think I was a little alarmed about was the Bank 2 voltage.. it was at 0.4 steady.. found I had used the PID for the Display. After correcting it. Found that the Voltage was moving as it should like Bank 1 now.
What is still alarming.. is the higher LTFT on Bank 1.. it at times is still 14.8 %.. as compared to Bank 2 which at a much lower percentage.
I have been listening to the popping sound from the tail pipe. The popping is coming from the Bank 1 side..I am wondering if I have a valve problem ? I don't hear any ticking at the engine so maybe it is a burn valve ? Well take the valve cover off again Friday if I have time. Also might try a leak down test to see what the seal is on the valve and rings.
Will keep trying to isolate the problem. But any input on anything would be helpful from you guys.. thanks..
BC
04-18-2014, 02:29 PM
#19
TECH Fanatic
With you there, I have been fighting an issue with my intank fuel pump/B body tank. It would run fine cold and kill the pump when it got hot. I found that the electrical connection on the top of the sender assembly was melted as was the gray wire inside. The sending unit had failed as well. Lucky it did not start a fire.
Oh well, upgrading to Aeromotive pump and a brand new sender assembly.
Nice to finally see results on this issue since I have been trying to track down the problem for 3 years.
Oh well, upgrading to Aeromotive pump and a brand new sender assembly.
Nice to finally see results on this issue since I have been trying to track down the problem for 3 years.
04-18-2014, 02:48 PM
#20
With you there, I have been fighting an issue with my intank fuel pump/B body tank. It would run fine cold and kill the pump when it got hot. I found that the electrical connection on the top of the sender assembly was melted as was the gray wire inside. The sending unit had failed as well. Lucky it did not start a fire.
Oh well, upgrading to Aeromotive pump and a brand new sender assembly.
Nice to finally see results on this issue since I have been trying to track down the problem for 3 years.
Oh well, upgrading to Aeromotive pump and a brand new sender assembly.
Nice to finally see results on this issue since I have been trying to track down the problem for 3 years.
Lucky I had the Trunk Access panel, was able to open it up without dropping the tank, remove the sending unit and found the blacken connector. I cleaned it up. replaced what was needed and secured the terminal and connector and back on the road in no time thanks to the access panel. I know I had posted or informed other on some thread for this before.. to bad you didn't pick up the issue that I had.. would have saved you a few years of your life ! LOL..
BC
