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Congrats! You very well may have found the problems! Regarding the oil filler neck, there is an o-ring types seal for it. Part number is ACDelco 12632361, and is available from Amazon for $9.31 or Rockauto.com for $2.25. The o-ring also crosses over to a Fel-Pro 73193 and you might be able to pick one up locally at a NAPA, Advance Auto Parts, O'Reilly or Autozone. I say replace it. (I love spending other people's money ;-) ). As far as the fuel injector o-ring, it is possible that it became distorted when you reinstalled the injector rail when you did some earlier work. I doubt it is the injector itself.
Regarding your plans to run Seafoam or Berryman B-12, I would vote for the Berryman - it's a more powerful blend of solvents than the Seafoam. I am not sure about soaking the O2 sensors in gasoline. Never ran across that before, and i would be worried that the ceramic/polymeric substrates used in the manufacture of them might soak in enough gasoline and then after you reinstall them, they would outgas the gasoline and cause abnormal O2 sensor outputs.
With respect to your spark plugs, pull a couple of plugs from each side of the engine and visually inspect them. If they look halfway decent, then stick them back in. If they look sooty or grungy, spray them with some carb cleaner or brake cleaner and then put them back in.
Thankyou!
I am going to try and find the felpro first since I would like to get one asap and not wait for one to be shipped.
What should I do about the smoke that was leaking near the cyl 1 injector? Is that a bad oring or like you said being distorted? I'm sure its something that has to be fixed anyways even though it was little right?. Do i just pull the injectors and pick up some new orings or how do I go about that? I never like to mess with injectors for some reason.
After I fix the filler tube oring and depending what you suggest about the injector I will do one last smoke test. If no smoke then I will use a can of B12, clean the plugs and ig all i can do is leave the 02 sensors. I though there was a way to clean them. Then after a couple days of driving in the conditions the problem tends to happen, if nothing happens I will be satisfied that the problem is fixed. Not doubting anyone but I feel like this is just too simple and dumb to not be the culprit. Well just have to see and keep rollin with the punches.
There is no difference injecting smoke through the throttle body instead of the evap connection correct?
Thankyou again for the detailed response!
First, I am not sure if there is any difference between injecting smoke through the throttle body versus going through the EVAP test port.
I think your plan sounds good an logical. Remember to disconnect your battery for at least 30 minutes so the PCM can "forget" all the parameters it programmed itself with as a result of the vacuum leaks. Then begin driving normally (whatever that might be for you ;-) ) and the PCM will relearn everything it needs to know over the next few hundred miles.
Regarding the #1 fuel injector and the apparent vacuum leak around it. Yes, you will need to replace the o-rings. Be sure and replace all the o-rings, top and bottom. You can purchase a complete set of both upper and lower o-rings as Fel-Pro, Standard Motor Products/BWD, and ACDelco all sell them. On Rockauto.com, they sell for somewhere in the $10 - $13 dollar range. When you reinsert the fuel injectors, either into the rail or into the intake manifold, remember to lubricate the o-rings using fresh engine oil so they go in smoother.
I understand your hesitancy about messing with fuel injectors, but on the 5.3L engine, they are fairly straightforward and are not that difficult. Just take your time, remember to lubricate the o-rings and just kind of wiggle them into place gently and you'll be fine.
Now, if the web gods permit, I'll attempt to post my first image in a forum...(drum roll sounding (or is that internet thunder))... The location of the EVAP test port on a 99 Silverado 5.3L engine
The EVAP port is to the left of the fuel pressure regulator and just to the right of the large wire loom.
Again, good luck and it has been a pleasure helping you!
Well as expected, after all the research and time spent working on the truck over the weekend and feeling like I was getting somewhere, driving the truck for work today the same symptoms occurred and there is no difference from before even after fixing vacuum leaks.
The first smoke test I did I had smoke from the oil filler neck and one of the injector seals just a little bit as seen from before. I removed the valve cover, bought a new filler neck because i had to break the old one out of the valve cover and after installing everything, I figure I would do a smoke test before I started to mess with the injectors and freeze in the cold more. I pumped a lot of smoke into the intake and after fixing the filler neck, there were no leaks to be found at all. Nothing from that one injector that time. Mind you I did this again when the truck was cold, im not sure if i should have done it while hot but maybe the injectors would leak while hot i have no idea. Pulled a plug and it looked normal as well.
I have no idea what this problem could be at this point. Im at a total loss. Idk if the pressure regulator even plays a role in this anymore.
What happened today was this. After my shift, got in the truck and started to drive on a highway 55mph+ where the problem occurs. After a min or 2 of driving I let off the gas praying I would not hear popping on decal, well as soon as i let off I heared it popping and i knew the problem was not fixed. From there the engine light started flashing as usual and this happened even while at operating temp. Got to a stop light and sat in the truck shaking while it was misfiring but for some reason, usually when i sit at a light for a while, the engine will correct itself and run completely normal after getting on the gas again. The engine light stopped flashing of course and was not lit solid. However i notice more gas consumption even though it runs fine. I have a video of the scanner running while the truck was missing and flashing the engine light. When I got home, even with no solid enging light, I scanned the codes and of course a P0300. I dont understand, there is not a single vaccuum leak unless I need to smoke it again while being hot but to be honest I think that can be taken out of the equation. I just have no idea what to check next.
I knew that the leaking from the filler neck was too simple to fix this issue. Just my luck lol
The thing that strikes me the most is that both bank 2 O2 sensors are now reading high positive while the bank 1 sensor 1 (pre-cat) is normal and the bank 1 sensor 2 (post cat) is reading high positive. There is definitely something going on with your bank 2 side of the engine. FYI, bank 1 is the driver's side and bank 2 is the passenger side.
Have you been able to see if the android app you are using can display historical and current misfires for each cylinder? I ask because I am halfway thinking you might have one or more potentially bad ignition coils or spark plug wires that are at the very least somewhat temperature sensitive.
Just remember, when an engine runs rough, it is normally something related to spark or fuel. Have you checked your fuel pressure lately? Have you checked to make sure your fuel pressure regulator is behaving as it should (test instructions are in the Haynes Manual). Are all the fuel injector electrical connectors plugged in and seated properly?
If you are using an android device, download and install the Torque Pro app as it will read and display misfire counts by cylinder. If you also have a tablet, you can also install Torque Pro there as well and have 8 different displays, one for each cylinder, on a single page and you can see which cylinder or cylinders are misfiring.
If you don't have an android device and are using an iPhone, do some research in the various OBDII diagnostic apps available in the Apple Play store and find one that will display misfires by cylinder.
Hang in there and remember the basics. Spark, air, fuel, compression. I understand how you feel as last summer my riding lawn mower drove me nuts because of some iffy crimped electrical connections. Individually they were fine. But when three or four marginal connections are put together in series along with dirty contacts in a switch, then the diagnostic fun begins. Took me about 20 - 30 hours of troubleshooting in order to track down the reason why it would run while in neutral with the brake/neutral pedal depressed, but would die as soon as I took my foot off the brake/neutral pedal the engine would die even thought the gear selector was in the neutral position. Moral of the story, keep your cool and go back to the basics.
Now a question for you about your homebrew smoke generator. Did you make one using plans found on the internet? If so, would you mind sharing that website with me?
I bought the bafx scanner for ios which uses wifi with the OBD Fusion app which is apparently the best for ios. Ive tried so hard to be able to track down how to check perimeters for misfires and I cannot but noone else seems to have problems, i believe its because they own a car where enhanced PID's can be purchased ---> from what ive read online, there are more in app purchases for enhanced PID's but it is for certain brand cars and Chevy is not one, allowing them to read misfire data. I read one forum saying Dashcommand has a $10 in app purchase after buying the app for gm specific year stuff but thats it. I am going to make another thread to see if i can get help finding misfire perimeters. I wish I could use torque pro but i dont think i can with my wifi scanner.
I really like how you pointed out that there could be a temperature sensitive issue. Today after work, and after checking as much as possible to gain more knowledge about the OBD Fusion app, I got in the truck and let it idle cold while i messed with the scanner for about 5 mins to look for misfire perimeters etc. Truck was probably 160F when I got on the highway and it ran normal the entire distance, no issues. Probably because the truck was no cold but warmed up. Could definitely be something to note. I dont know too much about open and closed loop but maybe there is something going on with that as the truck ran fine "warmed up"
A few posts ago, I checked the fuel pressure and the details from that specific test are there, I dont want to explain again making this post super long and maybe steer attention away. I would say the diagnosis was somewhat normal, still could be an issue though.
I tested the pressure regulator by pulling the vacuum hose and it was completely bone dry so i figured that was not the issue and if the diaphragm inside was the culprit, the issue would happen 100% of the time. Where can i access the Haynes manual to test this thing more?
I believe all the injector plugs are good and when i did that second smoke test, there was no leaking from anywhere so i figured the seals were tight. However im not sure if i should smoke test the engine hot.
I hear ya there on trying to diagnose an issue lol. All day everyday I go to work and constantly think about this truck and what could be the issue/how to use the scanner/staying up working on the truck/and just new ideas as each day passes with the help on here and its really draining me lol.
For my smoke tester, im mostly compiled information from youtube videos and I took the information to make my own so there is no direct link i can share. Pretty much a replica of theirs though. How I have mine setup is a mason jar, sock, baby oil, soldering iron, bic pen, vinyl tube, glove, zip ties, epoxy, and a bicycle pump. The mason jar has 3 holes cut into the lid, the cheap soldering iron goes into the middle, the cap of the bic pen is on one side and the body of it on the other all epoxied together. The jar contains an old sock soaked in baby oil so the soldering iron burns it into smoke. Vinyl tube runs from bic pen cap to a glove with a finger cut off with a zip tie to hold the tube on, then the glove is slipped over the throttle body. The cheap bike pump is then used on the bic pen body to pump air into the jar. Im not sure how much of a detailed description you needed. The video shows my first test with it and that was only with the iron plugged in for a min so there was little vapor. Give it like 3 or 4 mins and there will be a lot of smoke, and you can see it run through the tube into the throttle body. Got a vid for you
So where we sit right now is - get the scanner to read misfire data, find out if there is an issue with open / closed loop running since the truck was good warming up for 5 mins??, check the regulator off the Haynes manual which i need to get access to, look more into that fuel pressure test?? smoke test the truck while hot to see if injectors are leaking etc?? and thats all I can really think of right now. Im just trying to be as organized as possible so we are not all over the place.
Thanks for the details on the smoke maker! Sounds simple enough.
OK on fuel pump and fuel pressure regulator tests. Sounds normal to me as well.
Yes, the next thing you really need to do is to see what the misfire counts are so you don't have to rebuild the entire engine unnecessarily. If you can't find an iPhone app that will let you monitor the misfire data, you might want to consider borrowing a family member's android device, download Torque Pro and go that way. Or, you might be able to find a cheap 2nd or 3rd hand android device that works on bluetooth and wifi and go that route with Torque Pro. Yes, I do find it frustrating that there are apps for both platforms that are not mirror images of one another such that if it does this or that on an iPhone, it will do this or that on an android device as well.
I saw your other posting asking for iOS Fusion help. I hope you get lucky rapidly!!!
Same here lol. Hopefully we get down to the issue soon. Im not sure how long it will be until I get the misfire data checked but as soon as I do i will come back with a response unless more ideas keep being brought up on here. Shouldn't take more than 2 or 3 days max to figure this part out. Just before the weekend which should be a nice time to work on issues.
Jacob, I rewatched your "Values with No Misfire" video and at 1:06, I noticed there under test results, there is a entry for Misfire. I'm not sure but that might indicate that there is a way to monitor misfire counts after all. You might want o contact the people who wrote/support the Fusion app.
Again, God luck and it's been a pleasure helping you!
Ok lol, I feel dumb now but I got in contact with support from OBD Fusion and they have been very helpful to point me to where I was seeking and it was something I overlooked in the extra PID settings.
I got the misfires to read for each cylinder and the video is a clip of the scanner working and what do you know? Only the bank 2 cylinders are misfiring. Very helpful. Today was the worst it has been also, misfired pretty much the whole 30 min drive home. From here still im not sure what could be causing this because the intake gaskets are not leaking determined by the smoke test and I have no other ideas. The counter seems to regenerate its number after a second or so which is why i left the misfire history perimeters scanning as well.
Definitely something we need to know in order to figure this out. Happy to say now this scanner was a great buy. Will always have a use for it.
February 23rd, 2020, 12:07 AM
