Diagnostics and troubleshooting
Thread Starter
Racer
Joined: Jun 2020
Posts: 427
Likes: 54
From: oroville ca
Diagnostics and troubleshooting
Where can I go to get my car diagnosed and troubleshooted ? I have a check engine random misfires code and my car runs sluggish and I take it to the shop and they just tell me what it might be or what they think it is nobody wants to tell me why the car is throwing a random misfire Code ? I cant keep spending 150 a pop to each shop i go to anymore it is too expensive and i already know what is wrong with it can anyone fix it ?
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
Step one, get a scanner on the car that will pull down to the body level (most auto parts have such they can pull the codes for free), and get any active code that it has/are in history to tell you what cylinder is having the miss fire in the first place.
Once you know that cylinder has the miss fire, move the coil, the spark plug and plug from that cylinder to another one, and the other cylinder parts back to the problem cylinder and see if the problem follows the parts (run the car for a few days with the codes cleared, and scanned it again). Also, while you are swapping the electronic parts on the cylinder, double check the coil wires for problems on them as well.
Note were, when the spark plugs wires are being installed, make sure to dielectric grease the inside of the boots, so any trapped air will be released, instead of the air trapped, and when it heats up, popping the boot off the plug or coil to cause problems.
As for sluggish, most of the time this is a problem with the MAF sensor just needing to be cleaned.
Once you know that cylinder has the miss fire, move the coil, the spark plug and plug from that cylinder to another one, and the other cylinder parts back to the problem cylinder and see if the problem follows the parts (run the car for a few days with the codes cleared, and scanned it again). Also, while you are swapping the electronic parts on the cylinder, double check the coil wires for problems on them as well.
Note were, when the spark plugs wires are being installed, make sure to dielectric grease the inside of the boots, so any trapped air will be released, instead of the air trapped, and when it heats up, popping the boot off the plug or coil to cause problems.
As for sluggish, most of the time this is a problem with the MAF sensor just needing to be cleaned.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,551
Likes: 4,024
From: Cape Coral, Florida
Like I had said dealerships shy away from diagnostics because the time spent vs what they can make in income is not worth it for them..find a “diagnostic” shop and not a general repair one…ask them what kind of testing they use ??…a scope ??…great !!…if they don’t use one they are just parts changers…and like I had said in 1 hour there are probably 4 scope tests I can do to narrow down your issue and for 1 hour of diag time you’re paying at 150.00 a pop I’d expect that !!..and the thing is getting into the right diagnostic “funnel”…is it fuel, ignition, or mechanical ??…good luck !!
Last edited by C5 Diag; Feb 1, 2022 at 09:51 AM.
Thread Starter
Racer
Joined: Jun 2020
Posts: 427
Likes: 54
From: oroville ca
The misfires are random and at all cylinders so if we scan the vehicle it comes up " Random misfires" all cylinders so I just need to find a person or a "mechanic" who has run into this issue once or twice before so that I can have my car repaired for the cost of the problem and not all of this extra money I have to shell out in order to find one ...? There is only one way to go and it is to keep taking it to a shop who says they do diagnostics and then show them all of the prior shops work orders and tell them please all this has been checked and is not the issue so look at other things and not the same as all these other shops I have paid 150 ea to for a wrong or a guess at what my problem is .. .If you think it is a ba injector than figure out which one and change it out and see if that was it .. Why are they giving me what they think it is ? I want to know what it is ....!!! Is that to hard to figure out for these monkeys?
Thread Starter
Racer
Joined: Jun 2020
Posts: 427
Likes: 54
From: oroville ca
It is like I am living in the twilight zone or something here.... I do not live in some remote part of new mexico or something where there are no mechanics I live in the fricken bay area where there are more corvettes then any place on planet earth for christs sake
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Thread Starter
Racer
Joined: Jun 2020
Posts: 427
Likes: 54
From: oroville ca
Maybe this is why Corvette owners do not drive there cars that much, they figure that if they do drive it and it breaks down or has a problem, nobody knows how to fix them so thats why they leave them in the garage all the time .... I got it now
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,551
Likes: 4,024
From: Cape Coral, Florida
It is like I am living in the twilight zone or something here.... I do not live in some remote part of new mexico or something where there are no mechanics I live in the fricken bay area where there are more corvettes then any place on planet earth for christs sake