A mother with good hearing -- scary! But maybe she can troubleshoot the miss? LOL
Tonyrodz's Tahoe Build Thread
- Thread starter Tonyrodz
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
A mother with good hearing -- scary! But maybe she can troubleshoot the miss? LOL
OP
OP
Tonyrodz
Resident Resident
I wish!
OP
OP
Tonyrodz
Resident Resident
It's def something and it's driving me crazy trying to figure it out. Thx for the idea tho. What's a good way to check a coil?
I may have missed it, but have you been able to monitor live data for the misfires on each cylinder? To see if that's what it is?
OP
OP
Tonyrodz
Resident Resident
Actually I had the tech 2 to monitor misfires--got 0 misfires in all cylinders, but that was while in park--which it idles fine. I haven't done it while driving.
Hook up your Tech2 and look at misfires, leave it connected while you drive around and then check history. It can point you to a cylinder or 2 and then you can switch things around ( plug wire, coil, plug, etc) one item at a time and see if the misfires follow. It could be as simple as a plug wire or injector harness, or coil, etc. On my Denali I could feel it run rough under boost only and using the Tech2 I was able to find a plug wire that had burned inside the header boot that was supposed to keep them from burning. It was just discolored but must have affected the insulator inside the wire enough to cause misfires under load.
OP
OP
Tonyrodz
Resident Resident
I def will do that. Thx Mark.
Bigkevschopshop
Full Access Member
Kinda sounds like lean surge, or timing a bit off some something else.
I know that if your too lean at cruise under load it will slightly buck and make some coughing out of the exhaust. Lean misfire, depending on your tune the pcm may not pick it up. Pull the plugs yet?
You may look at the coolant temp sensor, sometimes a parameter off will cause things to go haywire. And only reason I go there is the issue is more prevalent at warmed up conditions.
Do you feel it buck at all or is it all in exhaust?????
If not, check for a header leak or exhaust leak somewhere, sucking air may be re igniting and causing things.... I know it sounds weird but Ive seen a car that ran perfect, no miss, full tune up, start popping out the exhaust, the shop tore the car down expecting the worse.... Turned out to be a cracked header at a weld, sucking in a small amount of air causing a reburn in the exhaust...
Also timing curve, if your timing curve was screwed with and its retarded for what it really wants at an rpm, it will do this junk also man...
I know its not helping but just throwing shit out there.....
I know that if your too lean at cruise under load it will slightly buck and make some coughing out of the exhaust. Lean misfire, depending on your tune the pcm may not pick it up. Pull the plugs yet?
You may look at the coolant temp sensor, sometimes a parameter off will cause things to go haywire. And only reason I go there is the issue is more prevalent at warmed up conditions.
Do you feel it buck at all or is it all in exhaust?????
If not, check for a header leak or exhaust leak somewhere, sucking air may be re igniting and causing things.... I know it sounds weird but Ive seen a car that ran perfect, no miss, full tune up, start popping out the exhaust, the shop tore the car down expecting the worse.... Turned out to be a cracked header at a weld, sucking in a small amount of air causing a reburn in the exhaust...
Also timing curve, if your timing curve was screwed with and its retarded for what it really wants at an rpm, it will do this junk also man...
I know its not helping but just throwing shit out there.....
OP
OP
Tonyrodz
Resident Resident
I would say it's more a chugging then a bucking. It was really noticeable driving up a hill, and when you keep steady pressure on the pedal. Honestly I haven't really done anything else since I did the alignment to it. Other things going on for me personally.
Not sure if it's my imagination but it seems like it takes just a little bit longer to warm up then it used to. Nothing crazy, and it might just be the thermostat. It doesn't take crazy long, but it just seems a tick longer. I'd think the tune would've stayed the same as before, since no one has even messed with that.
I plan on saving up for the BB tune. I know they'll be able to see if something wacky is going on. I'll have to pull the plugs too. That popping is really pissing me off. I haven't heard any exhaust leak under the hood, still sounds good under there--no ticking or other strange noises. Thx for the ideas, any and all suggestions are good.
iamdub
Full Access Member
I'd really be moving the tune up the priority list. If you're running lean, it could be a ticking (or popping?) time bomb. One good WOT blast could be the last. A good tuner would be able to see how it's running and what may be causing the pop. Fixing the issue (tune, fuel pump, injectors... whatever) rather than repairing it's consequences if left alone would be much cheaper. Until you know what's goin on, drive it easy.
