smoke test injectors

[glockworks21]

smoke machine arrived.. every injector is leaking. should i just replace o rings? bite bullet and replace all injectors?
Im hoping this is causing my "rythmic" idle when hot issue.
Andy you saw the video of idle. Think thats enough to do it?

Appreciate any advice..



Thanks
Dave

[82DMC12]

When you say every injector is leaking, you're talking about the black injector seals? They are really cheap, you should definitely replace all of them. They're probably hard as a rock. If you have smoke leaking out of the injector seals, then you potentially also have air getting sucked in to the cylinders which would certainly throw off your idle.

Glad to hear you got a smoke machine, need to make sure there are zero leaks coming out of that thing. I got everything fixed on mine except I was not able to stop some smoke from coming out of the oil dipstick tube, but that's okay because that's not under manifold vacuum anyway.

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[glockworks21]

When you say every injector is leaking, you're talking about the black injector seals? They are really cheap, you should definitely replace all of them. They're probably hard as a rock. If you have smoke leaking out of the injector seals, then you potentially also have air getting sucked in to the cylinders which would certainly throw off your idle.

Glad to hear you got a smoke machine, need to make sure there are zero leaks coming out of that thing. I got everything fixed on mine except I was not able to stop some smoke from coming out of the oil dipstick tube, but that's okay because that's not under manifold vacuum anyway.

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i assume so.. smoke trickling out from where seat of injector makes contact. I have not removed one yet.... I could not see any other leaks from anywhere else.

Thanks I will order seals !
Dave

[Timeless]

During a VOD job on my engine earlier this year I installed DPI injector seals. Had a leaking ISM and didnt want to mess around wanted everything in the vacuum department solid.

[82DMC12]

During a VOD job on my engine earlier this year I installed DPI injector seals. Had a leaking ISM and didnt want to mess around wanted everything in the vacuum department solid.I also did the DPI seals, they are great! Nice upgrade.

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[Delorean Industries]

https://deloreanindustries.com/most-popular/11-integrated-injector-seal-retainer-system/

[glockworks21]

so i received the new seals and installed 3 so far. I decided to check my work and hooked up the smoke tester again.
They still leak about the same. One of the 3 does not leak as much. I replaced the clips that hold the injectors as well. They have some play in them but not as much. what else should i do ?

Thanks,
Dave.

[WHO1DMC]

so i received the new seals and installed 3 so far. I decided to check my work and hooked up the smoke tester again.
They still leak about the same. One of the 3 does not leak as much. I replaced the clips that hold the injectors as well. They have some play in them but not as much. what else should i do ?

Thanks,
Dave.

I don't have any experience with these seals but I would think with a couple good heat cycles could help with getting a better tighter seal.

Otherwise the only better solution is DPIs injector clamps.



Dave B.

[glockworks21]

i teflon taped them. found old thread where dave t said to try. It worked.... 90% better. The real bitch about all of this is that im trying to get rid of the rythmic idle and it did nothing to help. It starts and idles perfectly for about 5 minutes. then it starts the dance and does not stop!

[82DMC12]

i teflon taped them. found old thread where dave t said to try. It worked.... 90% better. The real bitch about all of this is that im trying to get rid of the rythmic idle and it did nothing to help. It starts and idles perfectly for about 5 minutes. then it starts the dance and does not stop!Did you check your CO with a dwell meter afterwards? Every vacuum leak you fix will them change your idle mixture.

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[David T]

Very common for the seals to leak. They get hard and don't seal well. I used the teflon tape just to show you can seal the old. hard seals but replacement is always better. maybe the new seals you get now don't seal as well as the NOS stuff we used to get. Another very common leak is the "O" ring for the air pipe at the bottom of the mixture unit. Hard to see the small leaks when you have big ones.

[82DMC12]

Very common for the seals to leak. They get hard and don't seal well. I used the teflon tape just to show you can seal the old. hard seals but replacement is always better. maybe the new seals you get now don't seal as well as the NOS stuff we used to get. Another very common leak is the "O" ring for the air pipe at the bottom of the mixture unit. Hard to see the small leaks when you have big ones.Yeah but he has a smoke machine now. He's gonna be seeing EVERY leak.

Good news is, if all the vacuum leaks are fixed, now you know the problem isn't vacuum leaks!

Smoke machine was a smart move. Only way to be sure.

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[glockworks21]

none of the fixed leaks changed it at all. Its not even getting fully warmed up before it starts doing it. Is there anything mechanical or electrical that will kick in at a certain temp that is screwing it up? I know that may be a stupid question but how does it run so perfect every time for the first 5 minutes and then start the dance every time? The ism is new. I unplugged it last night when it was hot just to see what it would do. It just made it jump all over. It gets
half way to the first notch on temp gage and starts doing it. and its always the same. I do not have a dwell meter and have not messed with fuel mixture. all those injectors sealed up quite a bit better and it didnt change anything. It still has the exact same rhythm at the exact same time. can a bad o2 sensor cause any of these symptoms?

Thanks again

Dave

[82DMC12]

The O2 sensor does not begin to produce a reading until it reaches a certain temperature, like over 800 Fahrenheit or something. Normal operation of the lambda system is that the fuel mixture is set to a fixed reading until it begins to receive a signal from a warmed up O2 sensor. If you had to dwell meter, you would see the needle does not move while the engine is cold and it is warming up. 1 CO2 sensor begins to produce a reading, then you see the dwell meter go into the narrow swing that we often refer to. The swing is not the same as an idle speed that fluctuates. The engine actually tends to run a bit smoother when it is cold and warming up. Once it goes into closed loop hot operation, the engine gets its characteristic idle but the tack needle should be really quite steady at about 750 RPM.

At this point you're probably going to have to get a dwell meter so you can see what is happening and do four or five different tests that are possible only with a dwell meter. It's also possible your O2 sensor is faulty. Personally if it were me, and I didn't know when the last time the O2 sensor was replaced, I would replace it and then hook my dwell meter up and give it a check.

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[cdrusn]

The O2 sensor does not begin to produce a reading until it reaches a certain temperature, like over 800 Fahrenheit or something. Normal operation of the lambda system is that the fuel mixture is set to a fixed reading until it begins to receive a signal from a warmed up O2 sensor. If you had to dwell meter, you would see the needle does not move while the engine is cold and it is warming up. 1 CO2 sensor begins to produce a reading, then you see the dwell meter go into the narrow swing that we often refer to. The swing is not the same as an idle speed that fluctuates. The engine actually tends to run a bit smoother when it is cold and warming up. Once it goes into closed loop hot operation, the engine gets its characteristic idle but the tack needle should be really quite steady at about 750 RPM.

At this point you're probably going to have to get a dwell meter so you can see what is happening and do four or five different tests that are possible only with a dwell meter. It's also possible your O2 sensor is faulty. Personally if it were me, and I didn't know when the last time the O2 sensor was replaced, I would replace it and then hook my dwell meter up and give it a check.

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Thanks to your post I finally bought a smoke machine ($82 on amazon) to test for vacuum leaks. All my injector seals also leaked. I bought new seals from
ebay. I pulled the old injectors off and they were still flexible. I decided to clean up the injector seal support using a bottle brush that just fit into the hole. They were all dirty with black soot from the leaking seals. Then I used lacquar thinner to wipe the injector clean and the top of the seal support. Fitted the clip and new seal insuring it was all the way up the injector to where a stop can be felt. To ensure it does not leak I used Permatex ultra black sealant aroung the lip of the seal where it contacts the top of the support. Waited 4 hours and started up. Ran the best it has in years!!! Now to look for more leaks.

[glockworks21]

Had some free time and motivation today. Tried to remove the o2 sensor. I bought one months ago and never installed. It wont budge. I can get a wrench on it barely and would love to hit it with a hammer to knock loose but the wrench lines up right near the frame. I used penetrant oil and even torched it. My next thought is to drop axle on the transmission side to get more space. Any thoughts?

next part to the story. before I put it back together I held torch on the old sensor for a beat. I decided to make sure everything worked and drove it around a bit to get it warm. It was 80% better on the warm rhymitc idle... It was barely doing it at all. I parked it and let it cool... wanted to see what it would do from cold start and it was right back to its idle dance.

Would heating that sensor with a torch break something free? Does any of this make sense? I will get back under it on a day when its not 105 degrees outside and hopefully get the old one out.. Welcome to all advice on removing it... I was going to even try getting a deep socket and wratchet on i it but there is not enough room before you hit frame to get it in there..

Thanks again...

[82DMC12]

Just heat it up by running the engine! Can you cut the wire off of it so you can put a six-point socket on it?

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[Bitsyncmaster]

I do it all the time with an open end wrench but mine has anti-seize on it. You could cut the wire off and use a boxed end wrench to get better angles.

[Rich]

Get a proper 22mm offset O2 sensor socket, then carry on with whatever thread loosening ideas you come up with. It will allow you to use a breaker bar, assuming a box wrench is too short to provide the torque you need.

Any good auto parts store will sell you one like this. (https://www.amazon.com/dp/B01C4OB3XC/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=21797ada05292a61f677ffeeeb3204f7&content-id=amzn1.sym.cd95889f-432f-43a7-8ec8-833616493f4a%253Aamzn1.sym.cd95889f-432f-43a7-8ec8-833616493f4a&hsa_cr_id=0&pd_rd_plhdr=t&pd_rd_r=2412c4a3-00a1-4d33-81ce-28557ac9e057&pd_rd_w=tggrW&pd_rd_wg=m9FoI&qid=1691354533&ref_=sbx_be_s_sparkle_lsi4d_asin_2_img&sr=1-3-9e67e56a-6f64-441f-a281-df67fc737124)
These items (https://www.autozone.com/loan-a-tools/loaner-oxygen-sensor-socket) look like they're on loan.

These short offset sensor sockets slide into place without cutting the wire on the old or new one. The offset ratchet hole gives you max clearance from the frame and better leverage than a deep socket can.

Be sure to use anti seize on the sensor threads as a favor to the next owner. Not much and none of it on the sensor probe itself.

[glockworks21]

Get a proper 22mm offset O2 sensor socket, then carry on with whatever thread loosening ideas you come up with. It will allow you to use a breaker bar, assuming a box wrench is too short to provide the torque you need.

Any good auto parts store will sell you one like this. (https://www.amazon.com/dp/B01C4OB3XC/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=21797ada05292a61f677ffeeeb3204f7&content-id=amzn1.sym.cd95889f-432f-43a7-8ec8-833616493f4a%253Aamzn1.sym.cd95889f-432f-43a7-8ec8-833616493f4a&hsa_cr_id=0&pd_rd_plhdr=t&pd_rd_r=2412c4a3-00a1-4d33-81ce-28557ac9e057&pd_rd_w=tggrW&pd_rd_wg=m9FoI&qid=1691354533&ref_=sbx_be_s_sparkle_lsi4d_asin_2_img&sr=1-3-9e67e56a-6f64-441f-a281-df67fc737124)
These items (https://www.autozone.com/loan-a-tools/loaner-oxygen-sensor-socket) look like they're on loan.

These short offset sensor sockets slide into place without cutting the wire on the old or new one. The offset ratchet hole gives you max clearance from the frame and better leverage than a deep socket can.

Be sure to use anti seize on the sensor threads as a favor to the next owner. Not much and none of it on the sensor probe itself.






Thank You! Just ordered the tool on the link you sent. I will update later this week

Thanks again to all

[iflights]

I do it all the time with an open end wrench but mine has anti-seize on it. You could cut the wire off and use a boxed end wrench to get better angles.

I cut the wire off and used a deep socket with a breaker bar on mine.

[David T]

I cut the wire off and used a deep socket with a breaker bar on mine.

The safest way to get it loose is to use an acetylene torch and get it red hot. Even if you can get a good wrench on it and get it out cold, you risk ripping up the threads. When you install the new one they usually come with a dab of anti-seize already on them. If they don't, put a dab on, just be careful not to get any on the probe.

[glockworks21]

I gave up on the sensor. It appears to be original. breaker bars, heat, 3 different style o2 sockets/wrenches. Im outsourcing this one to a muffler shop at some point. it wont budge and its starting to round.. based on todays test i think its still working. So i will let it ride for now...

I am happy to say that thanks to the comments (and detailed instruction from Andy) I got the rhythmic hot idle pretty much solved. I ordered a cheap dwell meter on amazon. $32 Cold start it sat at 22.. when it started swinging it was 22-28.5 .. I got it to 15.5 -22.5 until the fans kicked on. then it stopped swinging for a minute and started back up and stayed 17.5 to 22.5 . I will let it cool down completely and test again from cold. Thanks again to all that helped.
Thanks Andy for detail on setting it. I missed your last post talking about dwell in this thread. I should have done that right out of the gate. It made all the difference.

Hope this helps someone in the future..

Dave..