S33k3r
Full Access Member
I'm just going to place this here... 
https://www.fixmyoldride.com/Chevro...e7e5cd24ed24635&at_ab=per-2&at_pos=3&at_tot=4
https://www.fixmyoldride.com/Chevro...e7e5cd24ed24635&at_ab=per-2&at_pos=3&at_tot=4
'02 Tahoe Randomly Running Rough
- Thread starter GrandStang
- Start date
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Another common problem that can cause your symptoms is a fuel pressure regulator. Here is a list of what that can cause, remember not all at the same time but sometimes just one of them.
Usually a faulty fuel pressure regulator will produce a few symptoms that will alert the driver of a potential issue.
Usually a faulty fuel pressure regulator will produce a few symptoms that will alert the driver of a potential issue.
- Misfires and a decrease in power, acceleration, and fuel efficiency. ...
- Fuel leaks. ...
- Black smoke from the exhaust.
Snowbound
Jim
I know I’m late to the game but as I read your first post with symptoms, dirty throttle body came to mind and I always clean the MAF sensor while I have the intake tube off. I noticed the first response was exactly what I was thinking. I would start there. Cost you under $20 for a couple cans of cleaner and maybe an hour of your time if you’ve never that type of thing.
I always try to tell people to start simple. Could it be an intake or a weak fuel pump or leaking regulator or compression issue? Sure it can. But intermittent doesn’t directly point to them things. Intake would give you misfire codes typically on corner cylinders. Weak fuel pump would be more lack of power issue. Leaking regulator you would see it smoke on start up and sometimes smell the fuel. Compression issue usually doesn’t come and go. I’m not saying they aren’t possible, I’m just saying start simple and work your way up.
Another thought I had is when you said you went to E85. That fuel does not have a very long shelf life. Depending on the station you got it from, if it doesn’t have a good turn over then you could have some watered down fuel. I’ve seen a lot of vehicles have hard start and rough idle complaints due to that fuel. And it’s mostly until engine get to operating temp. It’s not gonna hurt to clean the throttle body and MAF, the hardest part is gonna be the coolant line on the bottom of the TB. Being where you live, I would get a double sided barbed fitting and put the 2 lines together and bypass the TB completely. Your gonna lose a small amount of coolant, as long as you stick a bolt or something in the lines when you remove them, it will be so minimal, you shouldn’t need to top off coolant. Clean TB really good making sure to get where the throttle plate sits against the housing and the edge of plate itself on both sides. Reinstall everything and see what happens. If it doesn’t clear up, go fill up with some good fuel and run it for a few days. Hope this helps and you can get ahead of it.
I always try to tell people to start simple. Could it be an intake or a weak fuel pump or leaking regulator or compression issue? Sure it can. But intermittent doesn’t directly point to them things. Intake would give you misfire codes typically on corner cylinders. Weak fuel pump would be more lack of power issue. Leaking regulator you would see it smoke on start up and sometimes smell the fuel. Compression issue usually doesn’t come and go. I’m not saying they aren’t possible, I’m just saying start simple and work your way up.
Another thought I had is when you said you went to E85. That fuel does not have a very long shelf life. Depending on the station you got it from, if it doesn’t have a good turn over then you could have some watered down fuel. I’ve seen a lot of vehicles have hard start and rough idle complaints due to that fuel. And it’s mostly until engine get to operating temp. It’s not gonna hurt to clean the throttle body and MAF, the hardest part is gonna be the coolant line on the bottom of the TB. Being where you live, I would get a double sided barbed fitting and put the 2 lines together and bypass the TB completely. Your gonna lose a small amount of coolant, as long as you stick a bolt or something in the lines when you remove them, it will be so minimal, you shouldn’t need to top off coolant. Clean TB really good making sure to get where the throttle plate sits against the housing and the edge of plate itself on both sides. Reinstall everything and see what happens. If it doesn’t clear up, go fill up with some good fuel and run it for a few days. Hope this helps and you can get ahead of it.
OP
OP
GrandStang
TYF Newbie
So, just to update y'all.
My plan is still to remove and clean up the throttle body and MAF sensor first. Unfortunately, work has been keeping me busy and I haven't gotten a chance to do it. The only thing I've done in regards to this so far, is switch back to regular gas (I waited till I was almost on E before fueling up to avoid mixing).
It's almost been a week and it hasn't done it again. I'll keep you guys posted to see if and when it does it again.
My plan is still to remove and clean up the throttle body and MAF sensor first. Unfortunately, work has been keeping me busy and I haven't gotten a chance to do it. The only thing I've done in regards to this so far, is switch back to regular gas (I waited till I was almost on E before fueling up to avoid mixing).
It's almost been a week and it hasn't done it again. I'll keep you guys posted to see if and when it does it again.
