ruktosk Posted July 23, 2010 Report Share Posted July 23, 2010 I originally thought that my problems with the L36 in my GP were vacuum related. As in, that they were being caused by a cracked vacuum connector on the intake. See: http://www.w-body.com/showthread.php/47299-Vacuum-T-to-intake-on-L36 SES is on steady. Well, I replaced that connector, and it started up without incident. Before, when cold starting, it would stumble a bit and choke before correcting itself and running decently. After I replaced the connector, it started without the stumble/choke, but the idle was higher than normal. Around 1300 RPMs or so. It would try to come down slowly but the engine would start getting rough so they'd bounce back up to keep everything as smooth as it could. With the hood open before, it didn't sound like there was a leak. Now, I can audibly hear air moving. Part of me wants to say it's the upper intake manifold and possibly the lower as well, but both have been replaced before. Possible they've gone out again? The codes pulled were for the TPS which I replaced with a new one (and the code remains) and a cylinder 1 misfire code. The plugs and wires are all new, and yes, I still have the condoms on the plug boots. In the interest of full disclosure, I'll add that when I pulled the plug in cylinder 1 when I changed them, there was oil on the plug threads. Looking for a little guidance I guess. Thoughts? Quote Link to comment Share on other sites More sharing options...
AL Posted July 23, 2010 Report Share Posted July 23, 2010 Get those metal things out of there... They go around the plug boot but only seem to cause trouble... If you can hear air moving, you have a vacuum leak... Spray where you hear the noise with carb cleaner and if your engine changes speed its because the carb cleaner got into the motor... Once you find the vacuum leak, fix it and along with removing the heatshields on the plug wires, your misfire should go away Quote Link to comment Share on other sites More sharing options...
IRONDOG442 Posted July 23, 2010 Report Share Posted July 23, 2010 So the L36 runs like dirt, sounds to me like all things are status quo and running right to spec. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 23, 2010 Author Report Share Posted July 23, 2010 AL: When the car comes back home tonight I'll jump to it. So the L36 runs like dirt, sounds to me like all things are status quo and running right to spec. Guess you're an LQ1 owner. Quote Link to comment Share on other sites More sharing options...
AL Posted July 23, 2010 Report Share Posted July 23, 2010 Nope, he is a 3.5 DOHC owner Quote Link to comment Share on other sites More sharing options...
White93z34 Posted July 23, 2010 Report Share Posted July 23, 2010 So the L36 runs like dirt, sounds to me like all things are status quo and running right to spec. you talk like you haven't made good money off L36s see about replacing that spark plug, as for the high idle, try retightening down the bolts around the base of the intake 8mm they do not need to be super tight but not super loose either. maybe a IAC is bad as well. and be sure the cruise cable is not holding the throttle plate open a little. IIRC gen2 gp had a adjuster of sorts on the end by the throttle body. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 24, 2010 Author Report Share Posted July 24, 2010 Car came home and I went out and checked a few things. I still haven't removed the metal protectors from the plug boots yet. The engine is too hot for that right now. I will once it cools down though. My dad drove the car this morning to work. He said aside from the higher cold idle, it ran like it has been running for awhile now (like dirt). When he got the car home, I went out with scanner (arrived today) and cleared the codes. Once that was done, I started it up and let it idle for a few minutes. The TPS range/performance code showed up again, but there was no more misfire in cylinder 1. According to the scanner, TPS was working just as it should have, so I'm confident that the code is being thrown by unmetered air entering the system and the PCM freaking out because air/fuel ratio should be something akin to more than 0% throttle. Also took the opportunity to run a stream while it was idling. The long and short term fuel trim values made me laugh out loud. At idle, the STFT and LTFT were both bouncing between 19.4% and 20.1%. From what I've read, at idle those should be close to 0%. Gonna get a can of carb cleaner tomorrow and see if I can't find out where the leak is coming from, but based on the numbers I saw, I'm pretty sure it's the UIM/LIM gasket. Quote Link to comment Share on other sites More sharing options...
AL Posted July 24, 2010 Report Share Posted July 24, 2010 With those fuel trims, you are definitely getting unmetered air into the engine... However, I dont think it would be running that rich if it were a gasket, I have a feeling its more along the lines of a vacuum line being cracked Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 24, 2010 Author Report Share Posted July 24, 2010 With those fuel trims, you are definitely getting unmetered air into the engine... However, I dont think it would be running that rich if it were a gasket, I have a feeling its more along the lines of a vacuum line being cracked I hope you're right. The UIM/LIM gaskets have been replaced already, though they both have quite a few miles on them now. Also, this may or may not be related. When last I changed the PCV valve, it was completely covered in oil. I know the MAP sits right on top of the PCV valve, and the MAP has a vacuum line going to it. If the PCV valve is covered in oil, could that mean that something isn't sealing right? Maybe an o-ring? Quote Link to comment Share on other sites More sharing options...
Andrew Posted July 24, 2010 Report Share Posted July 24, 2010 Get those metal things out of there... They go around the plug boot but only seem to cause trouble.?? I have left them on my L36, L67, and my buddies L26 and no issues. What are you talkin about? They are they to protect the boots from melting. Quote Link to comment Share on other sites More sharing options...
AL Posted July 24, 2010 Report Share Posted July 24, 2010 No... They cause them to ground out and cause misfires... Ask anyone at the first Dayton meet last year... My car started misfiring horribly and we took them off and ran better than it ever has... Try it and see if I am wrong Quote Link to comment Share on other sites More sharing options...
Crazy K Posted July 25, 2010 Report Share Posted July 25, 2010 No... They cause them to ground out and cause misfires... Ask anyone at the first Dayton meet last year... My car started misfiring horribly and we took them off and ran better than it ever has... Try it and see if I am wrong <--- witness Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 25, 2010 Report Share Posted July 25, 2010 No... They cause them to ground out and cause misfires... Ask anyone at the first Dayton meet last year... My car started misfiring horribly and we took them off and ran better than it ever has... Try it and see if I am wrong QFT -- I am reminded of this, I need to do this to my L36 tomorrow. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 25, 2010 Report Share Posted July 25, 2010 No... They cause them to ground out and cause misfires... Ask anyone at the first Dayton meet last year... My car started misfiring horribly and we took them off and ran better than it ever has... Try it and see if I am wrong QFT -- I am reminded of this, I need to do this to my L36 tomorrow. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 25, 2010 Author Report Share Posted July 25, 2010 Well, I didn't get to work on the car today. It was over 100 F in the shade, so we decided to wait until it cools off some. Maybe tomorrow or Monday, since it's supposed to be high 80s, low 90s then. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 25, 2010 Author Report Share Posted July 25, 2010 Stormed last night so it's a pleasant, if muggy, 72 F. Checked the car. Replaced any lines that I saw/knew were cracked. Did the carb cleaner test on the vacuum lines. Initially, I didn't get any results. The cleaner didn't make the idle change one bit. It was a little rougher than it should have been as always, but I didn't hear any change. So I decided to visually trace all the lines, using the vacuum diagram under the hood. I finally found the leak. The accessory tube that goes into the harness on the passenger side (to go through the firewall) was broken in half. Both broken ends were hiding under the battery tray. I'm going to go back out in a little bit and repair the line, as well as removing those metal things from the plug boots. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 25, 2010 Author Report Share Posted July 25, 2010 Alright. I sealed the broken vacuum line. Also took the boots off the plugs and cleaned my MAF (never done that before) very carefully with MAF cleaner. I did another visual inspection and everything looks okay. She still idles rougher than she should. And that TPS light just won't go away. After I clear it, she idles for about 5 seconds before throwing the SES again. I did another live stream while she idled. STFT and LTFT have improved considerably, but they're still not right. Both were bouncing between 9.9 and 11.2. So getting closer. I'm going to ask this again since I think it was missed in one of my earlier replies. If I forgot to put the rubber o-ring on the PCV valve before putting it back in, would that explain where the leak might be coming from? And why the PCV valve and it's recess were covered in oil? Might it also explain why it smells like oil burning under the hood when the engine has been driven awhile? Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 26, 2010 Author Report Share Posted July 26, 2010 No... They cause them to ground out and cause misfires... Ask anyone at the first Dayton meet last year... My car started misfiring horribly and we took them off and ran better than it ever has... Try it and see if I am wrong I'm a believer. I took her out to get a tank of gas and even with the vacuum leak I still have, I noticed that she's definitely got more pickup. Was driving down the road at 40 MPH and goosed the throttle and she put me back in my seat for a second. Quote Link to comment Share on other sites More sharing options...
ruktosk Posted July 30, 2010 Author Report Share Posted July 30, 2010 Well, I'll never forget the o-ring on the PCV valve again. Ordered a PCV kit and genuine Delco MAP sensor from RockAuto. I put them on this morning and what do you know?? The vacuum leak is now gone and STFT is bouncing right around 0. Not to mention my MAP is at 10 Hg in. No more SES with the TPS range/performance code. So the combination of the plug boots, accessory vacuum leaking and PCV leaking, caused my diminished performance, cylinder 1 misfire, TPS code, rough idle, and my vent selector not working. Now she idles like a purring kitten. Quote Link to comment Share on other sites More sharing options...
GPX Posted July 30, 2010 Report Share Posted July 30, 2010 So the L36 runs like dirt, sounds to me like all things are status quo and running right to spec.LOL (new L36 owner) Quote Link to comment Share on other sites More sharing options...
Addicted to eaton Posted July 31, 2010 Report Share Posted July 31, 2010 yeah them boot "Protectors" suck ASS! Ask galen about them! Quote Link to comment Share on other sites More sharing options...
ron350 Posted July 31, 2010 Report Share Posted July 31, 2010 Ruktosk can you please give me a little more information about the PVC and MAP. Were either of the o-rings split or missing on the PCV valve? Quote Link to comment Share on other sites More sharing options...
ruktosk Posted August 1, 2010 Author Report Share Posted August 1, 2010 Ruktosk can you please give me a little more information about the PVC and MAP. Were either of the o-rings split or missing on the PCV valve? The o-ring on the PCV was missing. I preventatively replaced the MAP since oil had been covering the PCV for something like 10,000 miles. The PCV kit came with the valve, the plastic cover, the rubber gasket for the cover, the o-ring for the valve and a spring for the cover. Quote Link to comment Share on other sites More sharing options...
ron350 Posted August 1, 2010 Report Share Posted August 1, 2010 Thanks for the additional info Ruktosk I will check mine tomorrow. Quote Link to comment Share on other sites More sharing options...
chrisflstf Posted August 1, 2010 Report Share Posted August 1, 2010 If you have misfires with the plug heat shields on, you have a BAD plug or BAD plug wire. Taking them off doesnt fix the problem. The misfire is from plug voltage arcing thru the plug or plug wire. Quote Link to comment Share on other sites More sharing options...
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