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Poor accelaration after 300k

250k

Full Member
Joined
Dec 10, 2012
Messages
27
Yes i made it to 304k miles...still going leaking oil...quart per month, however i need help with what is causing my poor accelaration. It is aweful from a cold start, almost wants to stall. When warmed up, 5 min, it just has bad hesitation from a stop. If on the freeway it feels like i took my foot off the gas when i actually have to the floor, 2 sec later it catches up and goes. I cleaned the throtle body, no change. I am on my second fuel pump, should be good for another 50k, changed spark plugs at 250k. What next?
 
Sounds like the same issue I had with my 2001 Buick Regal.
Catalytic converter was plugging up. Had no acceleration and would just not run good at a stop in drive. Never threw a code. Mechanic friend told me to hold my hand over the end of the tail pipe.  I could almost choke the engine off, it had no pressure to push your hand. (make sure to wear a glove) Good Luck!
 
My 2002 z71 has not had cat. conv. since 2003. But i had that same problem with a 93 jeep cherokee. My av just stumbles, jerks, hesitates,,,, really bad from a cold start, but even after warm throtle response lags, then vroom.
 
Check your Cats... They do plug up over time and the main symptom is loss of power.

If possible check under your truck after driving for a while and see if your cats are glowing red. A telling sign.

You can also check the back pressure but this entails drilling a hole in the exhaust in front of the cat to test the pressure within the exhaust.

Do you have any codes or a Check Engine Light?

Otherwise without removing the units not sure how to check them.
 
Ever do the intake gasket?

Normally throws codes but doesn't mean it HAS to...

Early model 5.3 engines came with a poorly engineered intake gasket. I replaced mine with a Felpro.. Sounds like I will have to do mine again soon since I seem to have 2 cracked heads... (Ugh..)

Rodney
 
First try cleaning the MAF sensor.

If that doesn't work try replacing the front O2 sensors.
 
Well my research last night led me to this

https://youtu.be/aDlHCjgYf8s

So this morning i diconnected the MAF sensor and hmmm its wasnt jerking or stumbling and that was a cold start. I got the crc maf cleaner used half a can. WOW....ITS A NEW TRUCK. I havent had this accelaration in over 100k miles, yes this was the first time in 304k miles or the first time ever i cleaned both the throtle body and maf sensor.

Thanks for your input everybody, but enoniam is the winner. Now on to my oil leak.

I will start a new thread. But has anyone hear of an oil switch leak? Found something here over the past few days.
If you could post a link to the thread regarding this thank you in advance.
 
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