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Resolved 2G - Replaced valve stem seals but now high idle.

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
I don't think the two are related, but more of info on what was done.

The car is a 2ga 95 gsx with the cam position sensor on the inner side of the cam sprocket.
I replaced the seals using the rope technique (stuffing the cylinders) and everything went fine. I put the cams back on, put the timing belt on. Had everything lined up. Before connecting the accessories, I tried a test run. Car started and ran at about 2k, a little above ran it for about 5-10 seconds then turned it off. Sounded great too...

I thought maybe needed to have accessories, so that the water pump would be working, but putting everything back on and trying again, same issue. I ran it a little longer, but rpms didn't go down. Got it up to temp, played around with the throttle pressing it all the way down and that dropped rpms a little (now it was running at 1500-1700), but not much still double what it should be. BISS was already trimmed a while back.

With what I touched, I can't think of anything that would have caused this (thus why I'm posting here).
I didn't touch the cam sensor in any way, but I also didn't look at it too much or check it as I figure it was bolted in and I didn't need to do anything with it.

I didn't have any codes and unfortunately couldn't check dsmlink as my laptop died (battery)(working on car at friends house so can't check it at the moment).
Wondering if anything in the area that I was working on could cause something like this or maybe this is just target fixation and I should be looking elsewhere.

Should I look for anything in DSMLink when I get the chance to try it again?
 
Last edited by a moderator:

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
So after adjusting the TPS(which probably didn't need to be adjusted in the end) and looking through logs and checking for any kind of leak over the past week....it turned out to be how I moved the cruise control cable(The cruise control is no longer working so I pulled the module out but left the control cables at the time). Since the cable sat above the valve cover before I started the initial work, i moved(jammed) it so that it was moved to the underside of the lip just after the hood to keep it out of the way. This was messing with the throttle cable and keeping it at....well...that 2k rpm.

After getting a fresh start yesterday, I popped the hood, stared at the engine bay trying to decide what to do next....I saw the cable, thought no, f*** you, that can't be it....moved it out of the way and started the car....
started at 1250-1300...dropped down to 750....all numbers in the log looked pretty good as well.... I can't face palm hard enough though...

My O2 sensor did suddenly stop working over the time I did the work(I have logs before I started and it was working)...I was able to replace it and was getting the rise/fall vs the .02/.04v reading I was getting after putting everything back together.

I also had 2 bolts left(10mm).....looks like I missed a couple timing belt cover bolts...

So, I apologize for consuming your time in what was a misstep on my part and also want to thank you folks and appreciate the recommendations as it did help to look at other things that I hadn't looked at or checked and was able to confirm throttle setup and other values.

@pauleyman "Anything you touched that could affect airflow into the motor"
While your comment was broad, it was, essentially what it came down to...however, I was fixated on the vacuum lines and sensors, all things that I had actually changed....not the simple mechanical aspect...sigh....
 

Sirius1995

Proven Member
117
18
Jun 15, 2021
Hattiesburg, Mississippi
you might need to relearn TPS, if valve stems been leaking badly, it means it has been running with a little bit of oil in the mixture and causing blue smoke from exhaust, now if it's sealed properly, you might wanna try to relearn TP sensor, also checkout your IAC, if you have ECMlink, just check that everything is between the tolerance. also a air leak would cause higher RPM. take some brake cleaner and spray it on intake and injectors and TB to see if it starts to run higher rpm, if it does, it has a air leak somewhere, and remember, spark plugs tells you almost everything you need to know
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
Just in case, did you connect back the PCV valve hose to intake manifold? or didn't you see that the PCV hose is hardened or damaged when you removed?
I made sure to connect the two hoses that were connected to the valve cover. Hoses are pretty fresh, so I ruled that out pretty immidiately.
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
you might need to relearn TPS, if valve stems been leaking badly, it means it has been running with a little bit of oil in the mixture and causing blue smoke from exhaust, now if it's sealed properly, you might wanna try to relearn TP sensor, also checkout your IAC, if you have ECMlink, just check that everything is between the tolerance. also a air leak would cause higher RPM. take some brake cleaner and spray it on intake and injectors and TB to see if it starts to run higher rpm, if it does, it has a air leak somewhere, and remember, spark plugs tells you almost everything you need to know
I was getting smoke out the back but didn't see any when I started it up or when it got up t to temp(fwiw)...
I'll look into the TPS. I do have ECMlink...unfortunatly, my laptop battery died(cheap replacement that didn't last more tan a year) before I could get some numbers.

I was trying to think of where an air leak could come from considering where I was working...unless something got loose...but this seemed pretty high for something loose... :/

Will try the brake cleaner.

So that was the thing. The sparkalators seemed to be pretty clean. No oil contamination. Though I will say, the car has been driven quite a bit less since this whole pandemic and I didn't have an issue with blowing smoke prior....The valve seals have not been replaced to my knowledge prior to getting the car...and that was back in 2003/2004 ...a good number of years. Timing belt was changed though about 5 years ago.
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
Anything you touched that could affect airflow into the motor you need to check.
I only touched components on the belt side....which is why I'm a little puzzled. The lines connected to the valve cover was the extent of airflow related components. This is why I was wonding if the Crank or cam sensors could cause some sort of weirdness like this. Again, target fixation on my part...but being this is the first time I've had to do this much work on the car, i'm just trying to make sure the T's are dotted and I's are crossed on me missing anything.... :/
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
You didn't touch fuel rail or any vacuum lines?
No. I had no need to touch those. Anything under the valve cover was fair game though...
Only the PCV and the other line that goes to the BOV would be the only lines I touched. I've largely returned the car to stock due to the awesome restrictions we have here in Cali and needing to get the car smogged.
 

Kryndon

Proven Member
809
464
Jan 10, 2014
Bulgaria, Europe
Charge up your lappertopper hook it up to good ole Link and log a cold start all the way thru fully warmed. Once fully warmed check your airflowperrev value as well as ISC pos and TPS volts. If those are out of spec (airflowperrev ~0.25-0.28 g/s, ISCpos ~30, TPSVolts @0.63/0.65v idle), tweak as necessary to get them in line. After having the battery disconnected for so long things such as ISCLearnedAdj and fuel trims are reset. And now that you allegedly fixed your air leaks, the ECU needs to readjust itself for that.
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
Charge up your lappertopper hook it up to good ole Link and log a cold start all the way thru fully warmed. Once fully warmed check your airflowperrev value as well as ISC pos and TPS volts. If those are out of spec (airflowperrev ~0.25-0.28 g/s, ISCpos ~30, TPSVolts @0.63/0.65v idle), tweak as necessary to get them in line. After having the battery disconnected for so long things such as ISCLearnedAdj and fuel trims are reset. And now that you allegedly fixed your air leaks, the ECU needs to readjust itself for that.
Bringin the power cord this time....flakey laptop battery as I found out last night.
I'll get a full log and check the values as you noted. I only had the battery unplugged for maybe a day or two if that. I'll make sure to check all hoses again just in case something got jangled....
 

Sirius1995

Proven Member
117
18
Jun 15, 2021
Hattiesburg, Mississippi
I was getting smoke out the back but didn't see any when I started it up or when it got up t to temp(fwiw)...
I'll look into the TPS. I do have ECMlink...unfortunatly, my laptop battery died(cheap replacement that didn't last more tan a year) before I could get some numbers.

I was trying to think of where an air leak could come from considering where I was working...unless something got loose...but this seemed pretty high for something loose... :/

Will try the brake cleaner.

So that was the thing. The sparkalators seemed to be pretty clean. No oil contamination. Though I will say, the car has been driven quite a bit less since this whole pandemic and I didn't have an issue with blowing smoke prior....The valve seals have not been replaced to my knowledge prior to getting the car...and that was back in 2003/2004 ...a good number of years. Timing belt was changed though about 5 years ago.
I'm pretty sure after you check your ecm link, it's obvious whats wrong, just charge the laptop or replace battery, Sirius engines have a lot of problems with throttle body so wouldn't be surprised if it's linked to that as well
 

pauleyman

DSM Wiseman
8,011
2,607
Nov 19, 2011
oklahoma city, Oklahoma
Glad you found it. I missed it before but for future reference, it's not possible for a vacuum leak to cause an idle over 1500. If the ECU thinks throttle is closed it will cut fuel at 1500. This is the same thing that happens when idle cycles. On a 1g, there is a physical idle position switch. On a 2g, it is integrated as part of TPS. You would see this in link as a throttle closed. It would never be closed in this particular case as you've essentially held the throttle open.
Hope that helps further understanding.
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
Glad you found it. I missed it before but for future reference, it's not possible for a vacuum leak to cause an idle over 1500. If the ECU thinks throttle is closed it will cut fuel at 1500. This is the same thing that happens when idle cycles. On a 1g, there is a physical idle position switch. On a 2g, it is integrated as part of TPS. You would see this in link as a throttle closed. It would never be closed in this particular case as you've essentially held the throttle open.
Hope that helps further understanding.
I guess the one thing that puzzled me was that I physically tried to close down the butterfly valve on the throttle body. I would have thought that it would have closed and didn't even consider the effect that the cruise control linkage would have. I had even adjusted the tps to .63v prior to discovering my error. When I did move the linkage, my tps volts dropped to .43....
My throttle in link registered at 1% IRRC, so again...this really was something that made no sense to me at the time.

Indeed though, glad I found the issue. :)
 

pauleyman

DSM Wiseman
8,011
2,607
Nov 19, 2011
oklahoma city, Oklahoma
I guess the one thing that puzzled me was that I physically tried to close down the butterfly valve on the throttle body. I would have thought that it would have closed and didn't even consider the effect that the cruise control linkage would have. I had even adjusted the tps to .63v prior to discovering my error. When I did move the linkage, my tps volts dropped to .43....
My throttle in link registered at 1% IRRC, so again...this really was something that made no sense to me at the time.

Indeed though, glad I found the issue. :)
You should be able to see easily if throttle is closed or not from the bracket on the throttle body itself. If cable isn't a teeny bit slack something is holding it. Easy double check on any car including carburetor also
 

XC92

Proven Member
1,387
286
Jul 22, 2020
Queens, New_York
Is high idle something that can potentially have many causes? My 1G turbo's been idling semi-high, between 1000-1300, even after driving it a while. I'm going to do a thorough diagnostic so not looking for specific answers here, just trying to get an idea of how complex this could potentially be.

One tell-tale though is that it cycles from 1000-1300 instead of staying at a steady value. That must mean something. Bad sensor perhaps, or a vacuum or intake leak? Time to rent some testing tools?
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
Is high idle something that can potentially have many causes? My 1G turbo's been idling semi-high, between 1000-1300, even after driving it a while. I'm going to do a thorough diagnostic so not looking for specific answers here, just trying to get an idea of how complex this could potentially be.

One tell-tale though is that it cycles from 1000-1300 instead of staying at a steady value. That must mean something. Bad sensor perhaps, or a vacuum or intake leak? Time to rent some testing tools?
I've seen several...and adding this new one to the list....
Vacuum leaks have been the cause for me, especially on those hose couplers after the intercooler. I've not had issues with the vacuum lines(egr and such) but I've heard those can play havoc as well...
I had a similar issue with the rev from 1000-1300 which turned out to be my FIAV(ISC?) in the throttle body. replaced it and issue was gone.
 

voodoogsx

Proven Member
312
9
Jun 2, 2004
Sherman Oaks, California
You should be able to see easily if throttle is closed or not from the bracket on the throttle body itself. If cable isn't a teeny bit slack something is holding it. Easy double check on any car including carburetor also
honestly, it felt like it was closed, It felt like it had hit the end and felt like what I had felt before....This is why i'm so puzzled by this....
 

Mech Addict

Supporting Member
982
414
Jun 9, 2019
Jackson, Wyoming
Is high idle something that can potentially have many causes? My 1G turbo's been idling semi-high, between 1000-1300, even after driving it a while. I'm going to do a thorough diagnostic so not looking for specific answers here, just trying to get an idea of how complex this could potentially be.

One tell-tale though is that it cycles from 1000-1300 instead of staying at a steady value. That must mean something. Bad sensor perhaps, or a vacuum or intake leak? Time to rent some testing tools?
I’ll look for your separate post, but with the amount of work on your car recently, trans, front case, etc. it could be nearly any little connector or line under the hood. Kind of like this post, it can be the little stuff that you don’t even think of, until it looks right at you. :ohdamn:
 

XC92

Proven Member
1,387
286
Jul 22, 2020
Queens, New_York
Yeah, I wasn't expecting any specifics, just a general idea of how wide-ranging the potential causes might be. Bunch of seemingly small bugs post-work, slightly leaking trans case, high idle, growling sound on clutch re-engagement. With all the work I've done something was bound to go wrong. But I won't be able to do much about it till spring. Too damn cold around here and frankly I'm a bit burnt out.
 
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