Low Idle and Shut off

[klee7013]

Sorry to make another one of these threads read alot of these just trying to make sure i check everything easy to check
Had a little over a month.

205k miles
2000 yukon xl 1500 4x4

Sometimes on first startups after its been sitting a while it wont crank right up.

Cleaned TB, MAF, changed oil and filter. Been using MMO in the gas tank last two fill ups.

It has a slight tick/knock at startup colder it is worse it is. But as it warms up the sound goes away

Next step i was gonna do is check gas pressure at the engine suppose to check out around 50 ish correct.

If that checked out good gonna change spark plugs and wires. gonna go to the iridiums at .4 because orignals are .63 right but with iridums suppose to go to .4 correct


Every now in then the check engine light comes on pulled code once and it read evap something. Need to get code next time it does it.


Any other ideas

Thanks in advanced.

 

[#1taho]

Do you have a scanner avalible? Check coolent temp sensor. See what it reads from cold. Should be about the same temp as out side. Give or take a few.

 

[klee7013]

I dont have a scanner. What model would you recommend.

 

[SLCHOE]

Next step i was gonna do is check gas pressure at the engine suppose to check out around 50 ish correct.

Do this first. It should be 55-62 psi key on engine off and 48-54 psi at idle. After you shut the engine off, it should hold the pressure.

 

[klee7013]

k. Ill check it. Changed the plugs today and wires it needed. They where not in great shape. seemed to do better let it idle for 30+ minutes and didnt cut off.

Also replaced cabin air filter and blower resistor. only had high fan speeds.
Going to change the oil again next weekend. Been a little over a month since last change and going to put a lifter cleaner in it towards the middle of the week and change oil. Do yall prefer/ recommend synthetic or certain brands.

Thanks slchoe

 

[klee7013]

PO101, PO171 PO300 AND PO452 AND PO453

 

[SLCHOE]

So did you clear the codes and all of thse codes came back or did you not clear them after you cleaned the MAF/TB? First codes could be related to a dirty MAF. Last two codes are for the fuel tank pressure sensor circuit being low/high respectively (P0452,P0453).

 

[about20ninj45]

I dont have a scanner. What model would you recommend.

bafx elm327 bluetooth scanner

 

[klee7013]

Got the codes cleared last weekend. So time will tell. Haven't had it idle out on us since i replaced the spark plugs and wires.

The check engine light came on after i put gas in yesterday but unable to get it scanned. And it came on one time before that and cut back off. Need to take it in and get it scanned.

Thank yall will keep you updated.

 

[SLCHOE]

The check engine light came on after i put gas in yesterday but unable to get it scanned. And it came on one time before that and cut back off. Need to take it in and get it scanned.

Thank yall will keep you updated.

Sounds like an EVAP code (P0440-P0459).

The light does not have to stay on to read the codes. There can be history or pending codes to view.