Problem
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Problem
[IMG]
[/IMG] i finished latest mod which was deleting pcv and running two of the above. got tired of to oil smell so i mounted in area near the horn and the air pump. well anyway i was driving car and after 15 minutues the car when getting into light boost it would miss and pop in the exhaust.
i decided to start heading home and it was missing bad and popping even at low rpms. i checked the wires and nothing arching but did notice that two of the plugs didnt seemed snapped down. well snapped them down and checked two of the easy plugs, looked nice and dry.
went for a ride and all felt well but after 10 minutes it started again.
can it be from deleteing the pcv? i cannot see that but????
bad plug(s)? fuel pressure is good so...
[/IMG] i finished latest mod which was deleting pcv and running two of the above. got tired of to oil smell so i mounted in area near the horn and the air pump. well anyway i was driving car and after 15 minutues the car when getting into light boost it would miss and pop in the exhaust.i decided to start heading home and it was missing bad and popping even at low rpms. i checked the wires and nothing arching but did notice that two of the plugs didnt seemed snapped down. well snapped them down and checked two of the easy plugs, looked nice and dry.
went for a ride and all felt well but after 10 minutes it started again.
can it be from deleteing the pcv? i cannot see that but????
bad plug(s)? fuel pressure is good so...
Last edited by NICK YOSKIN; Oct 16, 2005 at 01:24 AM.
Burning Brakes
Joined: Feb 2004
Posts: 1,108
Likes: 0
From: over the water Cali
Can you do a cylinder balance test for a bad wire or something. Likely plug wires. Check for misfires on a scanner in real time. I'll be watching the thread for the real answer though.
Team Owner
Joined: Mar 2003
Posts: 96,496
Likes: 82
St. Jude Donor '03 through '17
Nick I just put the bill in the mail to you! 
It should solve your problems, I'll call you in the AM. If the fix desn't work and I feel better I'll take a run over with my OHM meter.
It should solve your problems, I'll call you in the AM. If the fix desn't work and I feel better I'll take a run over with my OHM meter.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by jersey jay
Nick I just put the bill in the mail to you!
It should solve your problems, I'll call you in the AM. If the fix desn't work and I feel better I'll take a run over with my OHM meter.
It should solve your problems, I'll call you in the AM. If the fix desn't work and I feel better I'll take a run over with my OHM meter.
cool!
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
What did you mean deleted PCV? It can alter (thinking maybe) your mass flow rates especially at lower flow rates by changing PCV. Now your running SD and this may upset things just like un-metered air with MAF.
Other things like electrical problems are harder to speculate about with limited info.
Mike
Just noticed you edited your post, I’d start looking at PCV and air path.
Other things like electrical problems are harder to speculate about with limited info.
Mike
Just noticed you edited your post, I’d start looking at PCV and air path.
Last edited by Skunkworks; Oct 16, 2005 at 01:36 AM.
Team Owner
Joined: Mar 2003
Posts: 96,496
Likes: 82
St. Jude Donor '03 through '17
Originally Posted by Skunkworks
Just noticed you edited your post, I’d start looking at PCV and air path.
BINGO!
He should have it resolved in the A.M.
I stand corrected knowing Nick, he's in the garage right now fixing it!
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
Originally Posted by jersey jay
BINGO!
He should have it resolved in the A.M.
I stand corrected knowing Nick, he's in the garage right now fixing it!
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Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
thanks for feed back, ill hook up pcv. gotta tell ya though doesnt make sence. case in point that when the car goes into boost the check valve that we install before pvc doesnt allow air into the manifold. it doesnt miss and pop then?
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
There is no such thing as unmetered air with an SD tune. All the air is estimated from (IAT, RPM, MAP, and the value in the VE tables).
The PCV can cause trouble for the idle air control position. The TB is not in control of the air coming into the manifold via the PCV inlet, and the IAC cannot compensate enough when the PCV airflow is not controlled (it would be like having a huge hole in your TB).
You have to remember that the PCV is normally a controlled vacuum leak. If you eliminate the PCV valve you suddenly have an uncontrolled vacuum leak (again picture a big hole in the TB blade).
If you could post details on how it is setup, I could provide more input.
If you have the PCV inlet capped, then the PCV has nothing to do with your problem.
The PCV can cause trouble for the idle air control position. The TB is not in control of the air coming into the manifold via the PCV inlet, and the IAC cannot compensate enough when the PCV airflow is not controlled (it would be like having a huge hole in your TB).
You have to remember that the PCV is normally a controlled vacuum leak. If you eliminate the PCV valve you suddenly have an uncontrolled vacuum leak (again picture a big hole in the TB blade).
If you could post details on how it is setup, I could provide more input.
If you have the PCV inlet capped, then the PCV has nothing to do with your problem.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by QuickSilver2002
There is no such thing as unmetered air with an SD tune. All the air is estimated from (IAT, RPM, MAP, and the value in the VE tables).
The PCV can cause trouble for the idle air control position. The TB is not in control of the air coming into the manifold via the PCV inlet, and the IAC cannot compensate enough when the PCV airflow is not controlled (it would be like having a huge hole in your TB).
You have to remember that the PCV is normally a controlled vacuum leak. If you eliminate the PCV valve you suddenly have an uncontrolled vacuum leak (again picture a big hole in the TB blade).
If you could post details on how it is setup, I could provide more input.
If you have the PCV inlet capped, then the PCV has nothing to do with your problem.
The PCV can cause trouble for the idle air control position. The TB is not in control of the air coming into the manifold via the PCV inlet, and the IAC cannot compensate enough when the PCV airflow is not controlled (it would be like having a huge hole in your TB).
You have to remember that the PCV is normally a controlled vacuum leak. If you eliminate the PCV valve you suddenly have an uncontrolled vacuum leak (again picture a big hole in the TB blade).
If you could post details on how it is setup, I could provide more input.
If you have the PCV inlet capped, then the PCV has nothing to do with your problem.
thanks quick,
yes i have the inlet capped and safety wired nice and tight!
i ran cyclinder balance test at idle and % were close. my hp c
scanner shows no miss fires but as a test i unplugged wire and still showed no miss fire?
when i was working on my new set up the battery was dead and the alternator exciter wire wasnt hooked up so the car was idleing really ruff and almost like it was loading up. is it possible i killed the plugs?
i wouldnt think so as it idles nice but then 10 minutes into drive it runs like crap.
Last edited by NICK YOSKIN; Oct 16, 2005 at 12:11 PM.
Le Mans Master
Joined: Sep 2000
Posts: 6,976
Likes: 527
From: Clouds Over California
I have had my PCV completely sealed off (plugged both the PCV and the intake nubs). I have never had that problem. Recheck your plug wires Nick. I have the new part number for the plug wires I am using, and they are a GM factory wire...and they are awesome!
I had to go for a drive with the Tech II monitoring misfires...because I got no misfire at idle. Sure enough under load I got the misfires (while driving). The Tech II results while driving were 100% correct. I used some 118* boot ends and they were not that great a fit...ended up burning the crap out of one of the wires. It was causing a misfire and constant backfiring.
I had to go for a drive with the Tech II monitoring misfires...because I got no misfire at idle. Sure enough under load I got the misfires (while driving). The Tech II results while driving were 100% correct. I used some 118* boot ends and they were not that great a fit...ended up burning the crap out of one of the wires. It was causing a misfire and constant backfiring.
Last edited by Shinobi'sZ; Oct 16, 2005 at 01:37 PM.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by Shinobi'sZ
I have had my PCV completely sealed off (plugged both the PCV and the intake nubs). I have never had that problem. Recheck your plug wires Nick. I have the new part number for the plug wires I am using, and they are a GM factory wire...and they are awesome!
I had to go for a drive with the Tech II monitoring misfires...because I got no misfire at idle. Sure enough under load I got the misfires (while driving). The Tech II results while driving were 100% correct. I used some 118* boot ends and they were not that great a fit...ended up burning the crap out of one of the wires. It was causing a misfire and constant backfiring.
I had to go for a drive with the Tech II monitoring misfires...because I got no misfire at idle. Sure enough under load I got the misfires (while driving). The Tech II results while driving were 100% correct. I used some 118* boot ends and they were not that great a fit...ended up burning the crap out of one of the wires. It was causing a misfire and constant backfiring.
dude please send part #!
i think wires are problem too, they are loking really snotty
thanks
i was thinkin abourt msd wires for a gm truck but they are striaght, can be twisted to any shape though. i'd rather run gm.
BTW my arms are way to big to get front plugs! to much test and growth!
just kiddin.................................. ............
BTW hp tuners isnt showing miss even though i pulled plug wire
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
Odd, it sounds like an ignition problem, but it is strange that it only happens after the car is fully warmed up.
I don't see how it could be the PCV, but you might just rig it back up temporarily and go for a light throttle cruise to see if the symptoms come back.
Have you run a log while this condition is taking place? I would look at MAP, RPM, Spark, Estimated airflow, misfire counts on each cyl.
Also might want to check your misfire detection tables and temporarily set them back close to stock. People usually tweak those in base tunes and it ends up hiding real misfires.
I have also found the misfire detection to work really well in identifying a bad plug. I don't know about HP tuners, but EFI-live does it just like a tech II.
I don't see how it could be the PCV, but you might just rig it back up temporarily and go for a light throttle cruise to see if the symptoms come back.
Have you run a log while this condition is taking place? I would look at MAP, RPM, Spark, Estimated airflow, misfire counts on each cyl.
Also might want to check your misfire detection tables and temporarily set them back close to stock. People usually tweak those in base tunes and it ends up hiding real misfires.
I have also found the misfire detection to work really well in identifying a bad plug. I don't know about HP tuners, but EFI-live does it just like a tech II.
Last edited by QuickSilver2002; Oct 16, 2005 at 02:00 PM.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by QuickSilver2002
Odd, it sounds like an ignition problem, but it is strange that it only happens after the car is fully warmed up.
I don't see how it could be the PCV, but you might just rig it back up temporarily and go for a light throttle cruise to see if the symptoms come back.
Have you run a log while this condition is taking place? I would look at MAP, RPM, Spark, Estimated airflow, misfire counts on each cyl.
Also might want to check your misfire detection tables and temporarily set them back close to stock. People usually tweak those in base tunes and it ends up hiding real misfires.
I have also found the misfire detection to work really well in identifying a bad plug. I don't know about HP tuners, but EFI-live does it just like a tech II.
I don't see how it could be the PCV, but you might just rig it back up temporarily and go for a light throttle cruise to see if the symptoms come back.
Have you run a log while this condition is taking place? I would look at MAP, RPM, Spark, Estimated airflow, misfire counts on each cyl.
Also might want to check your misfire detection tables and temporarily set them back close to stock. People usually tweak those in base tunes and it ends up hiding real misfires.
I have also found the misfire detection to work really well in identifying a bad plug. I don't know about HP tuners, but EFI-live does it just like a tech II.
i dont understand why when i unplug wire does the scanner not show miss fire? i just checked scanner and there is no where to adjust miss fire out, then checked edit section too, nothing.
yeah my buddie was logging not saved though, ill see him in a little and get back. i do know that he a/r were up and down big time!
Melting Slicks
Joined: Mar 2002
Posts: 2,931
Likes: 2
From: Tx
The misfire detection is broken into 4 sections (idle, low, med, high). Lots of tuners completely disable the idle stuff.
It is a tricky mechanism to implement and tune properly on a motor with a big cam. It is trying to detect changes in crank speed between different firing points.
The adjustments are all in the edit tool. Should be under Engine Diagnostics (ususally not in the main engine tuning section).
The scanner then allows you to monitor misfire counts on each cyl. It has to see over certain # of potential misfires on a given cyl during a defined time interval before it will actually set a code... It is definitely not a binary thing.
It is a tricky mechanism to implement and tune properly on a motor with a big cam. It is trying to detect changes in crank speed between different firing points.
The adjustments are all in the edit tool. Should be under Engine Diagnostics (ususally not in the main engine tuning section).
The scanner then allows you to monitor misfire counts on each cyl. It has to see over certain # of potential misfires on a given cyl during a defined time interval before it will actually set a code... It is definitely not a binary thing.
Melting Slicks
Joined: Apr 2005
Posts: 3,418
Likes: 1
From: Chicagoland Area IL
Nick what plugs are you running? Because I’ve had some colder range plugs do some strange things in past under low load. Missed at low rpm and be fine up top when they got niece and hot (increased cylinder pressure).
Quick, I mentioned it may upset PCM like un-metered (MAF based) air. I know in SD mode mass flow is a calculation. My only point was with SD mass flow calculation may thrown off if air suddenly changed do to changes in PCV. This could be worse at lower demand then WOT.
Mike
Quick, I mentioned it may upset PCM like un-metered (MAF based) air. I know in SD mode mass flow is a calculation. My only point was with SD mass flow calculation may thrown off if air suddenly changed do to changes in PCV. This could be worse at lower demand then WOT.
Mike
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by QuickSilver2002
The misfire detection is broken into 4 sections (idle, low, med, high). Lots of tuners completely disable the idle stuff.
It is a tricky mechanism to implement and tune properly on a motor with a big cam. It is trying to detect changes in crank speed between different firing points.
The adjustments are all in the edit tool. Should be under Engine Diagnostics (ususally not in the main engine tuning section).
The scanner then allows you to monitor misfire counts on each cyl. It has to see over certain # of potential misfires on a given cyl during a defined time interval before it will actually set a code... It is definitely not a binary thing.
It is a tricky mechanism to implement and tune properly on a motor with a big cam. It is trying to detect changes in crank speed between different firing points.
The adjustments are all in the edit tool. Should be under Engine Diagnostics (ususally not in the main engine tuning section).
The scanner then allows you to monitor misfire counts on each cyl. It has to see over certain # of potential misfires on a given cyl during a defined time interval before it will actually set a code... It is definitely not a binary thing.
what values would be in those screen to disable? medium has #'s from 1400 to 41 from rpms 1200 to 2200. rpms from 2300 to 6500 are much higher 32767.
high rpm goes from 6500 to 7000 and all #'s the same 32767.
pullled all the plugs on the passenger bank and they look nice. pulled the tw o rear on he driver side and they definatley look darker though not oil dark. will pull two front in a little bit.
Thread Starter
Le Mans Master
Joined: Oct 2003
Posts: 8,862
Likes: 85
From: PA
St. Jude Donor '08
Originally Posted by Skunkworks
Nick what plugs are you running? Because I’ve had some colder range plugs do some strange things in past under low load. Missed at low rpm and be fine up top when they got niece and hot (increased cylinder pressure).
Quick, I mentioned it may upset PCM like un-metered (MAF based) air. I know in SD mode mass flow is a calculation. My only point was with SD mass flow calculation may thrown off if air suddenly changed do to changes in PCV. This could be worse at lower demand then WOT.
Mike
Quick, I mentioned it may upset PCM like un-metered (MAF based) air. I know in SD mode mass flow is a calculation. My only point was with SD mass flow calculation may thrown off if air suddenly changed do to changes in PCV. This could be worse at lower demand then WOT.
Mike
mike tr6 gapped @ 32