low res pulse only between 1 and 2 volts ac when read from pin b of icm harness
1994 camaro z28 almost stock lt1 with a4, it should read between 1 and 4 volts ac with a multi meter when tested at pin b of the icm harness as the engine turns over, but mine only went up to 2.1 at the highest. I have the gm opti with only about 5k miles on it and I'm wondering if the problem could be that the optical sensor lens is dirty and if that could cause the problem so maby I can clean the lens and fix the problem because it's a non-vented unit. I would replace the cap and rotor with the msd "vented" verson. the car doesn't have any codes and it starts runs and drives but has a stumble at idle and hesitates when accelerating so it robs most of the power. I'm hoping I don't have to replace the whole unit since the one that's in there has such low miles on it. if anyone has any suggestions that would be great thanks.
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Yep no problem, I will get it scanned on to my computer so you will be able to see everything.
Let me know if you don't get that or have any issues with the scans I took but I just sent it, thanks again for the help.
Making any progress?Let me know if you don't get that or have any issues with the scans I took but I just sent it, thanks again for the help.
Al in Tucson
Not really I have kinda been at a standstill lately. it seems difficult to find a used scope that has all the stuff with it for a decent price but I have been looking at a Hantek scope that runs through a pc, its a little over 100 bucks new. Have you had any experience with something similar to that? If I could get a more definitive result with a scope I would feel a lot better tearing into the car because even though I think it could be the opti I would hate to replace it and still have the same problem.
From what I understand about how that works is when you hook up the leads to the wire that you want to test the signal for like any other scope but once you get the signal it can be saved on the computer and I guess you can then look up your specific car in the software and it will give you an example of what a normal signal should look like so it can be compared against the one from the car that was tested. I guess it has 8 channels which seems like alot to me but more is better than not enough. If you have heard of this type of thing let me know if it seems like it would be worth a try for I think $110 on amazon and other places but I noticed it on amazon.
Send me a link to it. A storage scope just stores the waveform so you can see it later OR lets say the waveform is very slow. This waveform takes a few seconds to cross the screen. The start of it will be gone before you can see the end. So you store the waveform. It's the only way to see one complete sweep. By now I've probably confused the heck out of you. Back to what I said before. 99.99% of any problems in the Opti should set a code. Do you have a half decent code reader that works on your car? A 94 Z28 is OBD1. Don't know about 94 but my 95 has an OBD2 connector but is actually OBD1. Had to make an adapter to get my OBD1 scanner to work. I use TunerCat for some stuff on my car. Made the cable and downloaded the program. Had to get a USB to Serial adapter to make it work with my laptop. TunerCat has a very large following, lots of information on the web, and videos on youtube.From what I understand about how that works is when you hook up the leads to the wire that you want to test the signal for like any other scope but once you get the signal it can be saved on the computer and I guess you can then look up your specific car in the software and it will give you an example of what a normal signal should look like so it can be compared against the one from the car that was tested. I guess it has 8 channels which seems like alot to me but more is better than not enough. If you have heard of this type of thing let me know if it seems like it would be worth a try for I think $110 on amazon and other places but I noticed it on amazon.
Again, if you send me your scope I can try to repair it. Don't know if I can but I can give it a shot. I think it's adequate for what you're doing.
Win, loose or draw, I hope you're learning from this.
Al in Tucson
I can read codes I also use tuner cats and got my cable with that for the obd1 port to usb, I use scan9495 to data log and read codes. I haven't been able to take advantage of much with tuner cats yet because of this issue. I'm not getting any codes, that's one of the things that have made this so difficult unfortunately, that and the fact that I had a few things go out around the same time, fuel pump was weak, plug wire was arcing and something else that was small that I cant remember at the moment. Thanks for the offer to attempt to fix that scope and I'm sure you are correct that it would be adequate for the job, the thing I like about this option, if you think it will work for this application, is that since it runs through the pc it makes it so much easier to share a more complete test result rather than trying to take pictures or a video of the screen to be able to show on here for advice. Let me know if there is a problem with the link, and again thanks I really appreciate the assistance you are giving me here. Hantek 1008C PC USB 8CH Automotive Diagnostic Digital Oscilloscope/DAQ/Programmable Generator: Amazon.com: Industrial & Scientific I keep going back and forth in my head if I want to buy that or go a cheaper route like sending it to you to see if you can fix the scope I have, but if I can get this figured out it would be worth it with my car being like this for 3 years now I think its slowly driving me nuts.
The scope you found is very good. One thing, and I'm also positive it's just an error in the descrioption. It says the input coupling is DC. No mention of AC coupling. You use AC coupling to see a small signal riding on a large DC voltage. If you were testing the noise on an Alternator you would want to filter out the DC component, and just see the noise.
Do what you think is right. With a scope you can also "see" other signals, like the TPS, MAP, and so on. Scope is a must for discovering problems in the TPS.
Al in Tucson
Do what you think is right. With a scope you can also "see" other signals, like the TPS, MAP, and so on. Scope is a must for discovering problems in the TPS.
Al in Tucson
I noticed that too and I think it is a mistake. I want it to be able to test as much as possible if my opti stuff tests out to be fine. This is a link to there website where it has more specific's Hantek1008A - Hantek Electronic & Your testing solution provider From what I noticed it has it listed as, input DC, then it says input max and there it mentions DC+AC volts
Followed the link. Some of the items they were using for the various tests do not come with the scope. Did you notice the 20:1 antenuator? That divides the test voltage by 20. Keeps from blowing the input to the scope.I noticed that too and I think it is a mistake. I want it to be able to test as much as possible if my opti stuff tests out to be fine. This is a link to there website where it has more specific's Hantek1008A - Hantek Electronic & Your testing solution provider From what I noticed it has it listed as, input DC, then it says input max and there it mentions DC+AC volts
Mentioned before, 10:1 probes are around $10, 100:1 are around $20. 100:1 are good to around 2000 Volts. The other thing they used was a current probe. They clamp around the wire, no need to damage the insulation. I have one and almost never use it.
Al in Tucson
ok well I ordered that and as long as I have what I need for the first few tests I want to do on the opti wires that I was trying to test last, I can always order the other accessories as I need them depending on what happens with those tests. I will post when I get it and have a chance to use it, hopefully I will have some useful info from that and can start to fix things rather than tracking down the problems for a change.
All good just don't hook it to anything going to the coil.ok well I ordered that and as long as I have what I need for the first few tests I want to do on the opti wires that I was trying to test last, I can always order the other accessories as I need them depending on what happens with those tests. I will post when I get it and have a chance to use it, hopefully I will have some useful info from that and can start to fix things rather than tracking down the problems for a change.
Al in Tucson
Yeah I definitely wont do that, I got the same model that you looked at but it came with another accessory for a few extra bucks, I think it will come with the 20:1 antenuator, but when I checked the tracking it shipped from China so unfortunately it will be slow to arrive.
I got that Hantek pc scope in the mail today, I have the software installed so I just need to familiarize myself with it and I should have time to try it out on the car tomorrow.
I am trying to find a way that I can post the results of the test here but it wont let me do it in any of the ways I have used before. If I copy and paste its too big and if I try to add an attachment it says I cant upload that type of file. I tested the low resolution wire from the opti first and from what I see it looks normal but I am not an expert with those things by any means. I still have to test the high resolution wire but I need to figure out how to get it posted here.
I dont know why but it copied them more than one time each, it is two screen shots of the test, not 5
Low res looks about right except I can't read the voltage it's set at. Is there any way to get rid of the dead channels and make the image bigger?
And for some reason I didn't get an email that you posted this??
Al in Tucson
And for some reason I didn't get an email that you posted this??
Al in Tucson
41 - 60 of 68 Posts
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