Need advice

[BC327]

HI Everyone, I'm new here and having some issues with my 99 Yukon, 179k miles on it. All of the sudden today it started to hesitate at half throttle, or when I'm ******* the gas, if ease on it it's fine, if I mash the peddle it studders and will pop through the exhaust. I tuned it up completely about 6 months ago, good AC plugs, cap, rotor, wires ect. No check engine light on. Going change the fuel filter this weekend. Anyone else heard or had this problem? Any help would be greatly appreciated

 

[ccapehartusarmyINF.(ret)]

sounds more like maybe a vacuum leak your not getting any extra **** of smoke out of the exhuast? even though you dont have a check engine light stick a scan tool on it anyways you mite have a pending code
how does it idle on a cold start

 

[SunlitComet]

also run a fuel pressure check on a full throttle run and perhaps check the movement of the tps with a scanner.

 

[BC327]

sounds more like maybe a vacuum leak your not getting any extra **** of smoke out of the exhuast? even though you dont have a check engine light stick a scan tool on it anyways you mite have a pending code
how does it idle on a cold start

Haven't noticed a **** of smoke, it was dark when I was on my way home and it happened, the idle is fine when it's cold, first time ever I had to crank it for a bit to get it to start, thought it was because it was cold out 19° this morning. Doesn't matter if it's in drive or park, anything past half throttle it acts up.

 

[SunlitComet]

and for that matter test the maf as well.

 

[BC327]

Thanks guys, I will do the tests this weekend and let you know what I find out, of corse it happens when it's cold as hell out!

 

[ccapehartusarmyINF.(ret)]

Haven't noticed a **** of smoke, it was dark when I was on my way home and it happened, the idle is fine when it's cold, first time ever I had to crank it for a bit to get it to start, thought it was because it was cold out 19° this morning. Doesn't matter if it's in drive or park, anything past half throttle it acts up.

when you had to crank it for a bit to get it to start that time how full was the gas tank was it almost empty or was there plenty of gas in the tank?

that would kinda point me tword the fuel pump
has the fuel pump ever been replaced

 

[BC327]

Was wondering the same thing, it was at about a 1/4 tank. I'm not sure if it has, I have had the truck 3 years. Was thinking a tps, maf, ignition or fuel, will have to get into it this weekend and do all the tests. Thank you for the tips so far guys!

 

[SunlitComet]

as described it does not sound like the fuel level is the issue. does not make any difference if 1/4 tank or full. the pump does not decide to run depending on tank fill.

 

[ccapehartusarmyINF.(ret)]

no i know that. The only reason i asked is because both my tahoe and suburban if the fuel tanks on E and it sits over night it takes an extra couple seconds cranking before it starts
so i was makin sure that wasnt the issue