Rough idle wants to die
02-14-2015, 06:48 PM
#1
Instructor
Thread Starter
Rough idle wants to die
Little bit of background;
My transsmission went out and I replaced it, when I did that I changed plugs and wires. When I got it all back together again and started it up I noticed a stumble or miss that showed up while in drive setting at a stop light. I checked all the wires and plugs for connection and all the obvious stuff I could think of with no luck. I had a mechanic buddy of mine take a look at it with a tech2 reader and he said the low res signal was bad and to replace the opti. At this point there were no codes thrown and the check engine light was not on.
So I replace the opti and the same symptoms are there the wandering miss and stumble, so I sit on the problem for awhile and finally take it back to him and he says low resolution signal is still bad must be a bad opti. ( I had replaced with a new Delphi unit from summit) I don't buy this and the problem over time has become a little worse there is a popping coming out of the exhaust and the miss or stumble is now showing up at higher RPM still no codes have been thrown. So I decide to give Datamaster a try to see what I can see (total newb not sure what I am looking at but trying to learn as I go)
This weekend I decide to get to fixing this problem I checked the fuel pressure and all is within limits according to the FSM 44psi at key on pump off, holds at 42psi for at least 10 mins key off and drops to a steady 38 - 36 psi with idle when started. I checked everywhere for a vacuum leak can't find anything, swapped out the pcv valve and bought new o2 sensors to install. Now the interesting part (You may ask why O2 sensors because when I swapped the tranny I had them out and maybe I messed them up) So when I crawl up under the car to install the new O2 sensors I find the passenger one just setting in there, I must not have tightened it back up. Thinking what an idiot I am I go ahead and swap out the O2 sensors anyways and crank her up. Now she is running better no more pop coming out the rearend but still a slight stumble but way better. Take her out for a test drive and the stumble is still there at the stop lights and now it kinda wants to die. I get back home to the garage and it is idling bad sugeing and chugging a little. So I hook up data master again and run the file I have attached.
First part is just at idle, then after a few minutes I rev it up to about 2000 RPM for awhile and I get intermittent popping out the back. When I let off the gas to drop her back to idle it got real bad and wanted to just flat die, it also started to smell real bad like rotten eggs which I believe means it is too lean, that is the last part of the file. I am a little stumped on this and would appreciate any help you could give me.
Art
http://www.filedropper.com/afterdriveando2fix
My transsmission went out and I replaced it, when I did that I changed plugs and wires. When I got it all back together again and started it up I noticed a stumble or miss that showed up while in drive setting at a stop light. I checked all the wires and plugs for connection and all the obvious stuff I could think of with no luck. I had a mechanic buddy of mine take a look at it with a tech2 reader and he said the low res signal was bad and to replace the opti. At this point there were no codes thrown and the check engine light was not on.
So I replace the opti and the same symptoms are there the wandering miss and stumble, so I sit on the problem for awhile and finally take it back to him and he says low resolution signal is still bad must be a bad opti. ( I had replaced with a new Delphi unit from summit) I don't buy this and the problem over time has become a little worse there is a popping coming out of the exhaust and the miss or stumble is now showing up at higher RPM still no codes have been thrown. So I decide to give Datamaster a try to see what I can see (total newb not sure what I am looking at but trying to learn as I go)
This weekend I decide to get to fixing this problem I checked the fuel pressure and all is within limits according to the FSM 44psi at key on pump off, holds at 42psi for at least 10 mins key off and drops to a steady 38 - 36 psi with idle when started. I checked everywhere for a vacuum leak can't find anything, swapped out the pcv valve and bought new o2 sensors to install. Now the interesting part (You may ask why O2 sensors because when I swapped the tranny I had them out and maybe I messed them up) So when I crawl up under the car to install the new O2 sensors I find the passenger one just setting in there, I must not have tightened it back up. Thinking what an idiot I am I go ahead and swap out the O2 sensors anyways and crank her up. Now she is running better no more pop coming out the rearend but still a slight stumble but way better. Take her out for a test drive and the stumble is still there at the stop lights and now it kinda wants to die. I get back home to the garage and it is idling bad sugeing and chugging a little. So I hook up data master again and run the file I have attached.
First part is just at idle, then after a few minutes I rev it up to about 2000 RPM for awhile and I get intermittent popping out the back. When I let off the gas to drop her back to idle it got real bad and wanted to just flat die, it also started to smell real bad like rotten eggs which I believe means it is too lean, that is the last part of the file. I am a little stumped on this and would appreciate any help you could give me.
Art
http://www.filedropper.com/afterdriveando2fix
Last edited by gimpsy; 02-14-2015 at 07:25 PM.
02-15-2015, 02:54 PM
#2
Instructor
Thread Starter
Today while troubleshooting for this a loud clacking started coming out of the front of the engine. I traced the sound down to the opti with a screwdriver, when I am on the block I get normal engine sounds and when I am on the plastic body of the opti I get the clacking. Could it be the opti was failing all along? Ugh I guess I am pulling it out again. Any thoughts?
Art
Art
02-15-2015, 05:56 PM
#3
Burning Brakes
I reviewed your log and the erratic idle/rpm is ignition related. There are no other signs of trouble that could be causing fluctuating rpm/spark. There were some instances during the erratic rpm that had spark retard. It would be a good idea to start with the opti. Keep us posted.