Engine bogs

[CookieMonster401]

I own an LT 05 tahoe, 2wd with the 5.3 vortex. This only happens when I give heavy acceleration from a stop, until around 25 mph it bogs or "trips over itself". If I lift the pedal about an inch from the ground I feel a gain of power, even tho im lifting off the pedal. Once I reach 25, everything seems normal. I just recently went around unplugging my ignition coils one at a time too make sure none of them have gone bad, and every coil shows a decrease in rpms when I disconnect it from the motor. I have thought that it might be my knock sensors causing this problem, as when the engine is cold and under heavy acceleration you can hear a distinct ticking, or sounds more like if you shoot air from a compressor through a fan while it's on. If anyone has any tips or fixes, I'll be glad too take em.

 

[Doubeleive]

my first suspect other than a clogged air filter is the MAF sensor, sounds like you are having a air/fuel issue, rather than a spark issue, you could try cleaning it but that may not do the trick, what are the miles? typically I see maf's going goofy starting about 160k on average.
another thing to check is fuel pressure, you can pick up a fuel pressure tester at harbor freight for around $25.00 paying more than that for one is not necessary they all do the same thing.

 

[SnowDrifter]

I feel like I'm preaching fuel pressure as of late... But what's your fuel pressure doing?

Any difference based on drive time or tank fill level?

 

[adriver]

I had something with a similar action, but different noise. My oil filler neck wasn't sealing and I was sucking air through the base of it. Even with a new one, It would still suck in air, but only at full throttle in higher rev. I just took it out and just removed the filler neck and used only the oil cap. Probably not it, but its a quick look to see if the o-ring is visible, and you asked for anything it could be. I also like to hear myself talk. So if you have time to waste you can keep reading. This one time at band camp, I was typing stupid shit and wondering why the hell are you still reading this. I said everything I needed to half way through. The rest of this was just nonsense.

 

[iamdub]

Really sounds like weak fuel supply. That and clogged cats present virtually identical symptoms, but you mentioning ticking points me towards a fueling issue making it run lean. Check the fuel pressure while driving. I route the hose out from under the hood and under the wiper to hold the gauge against the windshield.

 

[CookieMonster401]

my first suspect other than a clogged air filter is the MAF sensor, sounds like you are having a air/fuel issue, rather than a spark issue, you could try cleaning it but that may not do the trick, what are the miles? typically I see maf's going goofy starting about 160k on average.
another thing to check is fuel pressure, you can pick up a fuel pressure tester at harbor freight for around $25.00 paying more than that for one is not necessary they all do the same thing.

Im not sure of my fuel pressure at the moment, but Ill check it soon. But this might give another hint? When I fill up my truck, it stops the pump on it's own (truck is on e, not full at all). Sometimes it will spit out gas after stopping the pump, some ******** backpressured problem, and I've been told that my carbon filter is probably busted, clogging my fuel fill or something, I just haven't had the time too look into that yet. People have mentioned too me that could be causing my power issue I'm just not sure how.

 

[CookieMonster401]

I feel like I'm preaching fuel pressure as of late... But what's your fuel pressure doing?

Any difference based on drive time or tank fill level?

If by difference you mean I'll have a quarter tank and my gas light will suddenly turn on, then yeah. I also have problem filling my tank, as when I try too insert gas it likes too puke it back out..

 

[SnowDrifter]

If by difference you mean I'll have a quarter tank and my gas light will suddenly turn on, then yeah. I also have problem filling my tank, as when I try too insert gas it likes too puke it back out..

Difference in the bogging problem you're describing with respect to the amount of fuel in the tank.

 

[Doubeleive]

Im not sure of my fuel pressure at the moment, but Ill check it soon. But this might give another hint? When I fill up my truck, it stops the pump on it's own (truck is on e, not full at all). Sometimes it will spit out gas after stopping the pump, some ******** backpressured problem, and I've been told that my carbon filter is probably busted, clogging my fuel fill or something, I just haven't had the time too look into that yet. People have mentioned too me that could be causing my power issue I'm just not sure how.

the fix for that is to replace the front & rear solenoids and evap canister, not hard to do you can get all the required oem parts for under $200 and it takes about 30-45 minutes to do, but that's just epa crap to prevent fumes from getting into the atmosphere.

 

[afpj]

ticking with load when cold...although not likely entirely responsible for your symptoms, it sounds like an exhaust leak. Check exhaust manifod bolts. Probably a few broken like the rest of us