Acceleration hesitation after turning on when warm

I’m hesitant to think it’s a transmission issue because it only happens if I turn it off and start it back up again. No CEL has been on recently

 

Just a thought !

Does your truck have a tach notice higher then normal rpm when this occurs??

The fact it is intermittent makes it harder to diagnosis.

It seems to happen when the truck is at operating temperature is shut off started put into drive.

It seems all most like a fuel filter which would not trip any codes but on any longer drive most likely it would get sluggish

Beat of Luck

 

Thanks for reminding me. I forgot about the fuel filter and changing that anyway.

 

Any update? Howd it go?

 

Still trouble shooting. I ordered a new MAF since idk how old the one I have is and figured It could just be old and tired. I’m also going to order some new vacuum lines and replace all under the hood and get a new fuel filter. Might deal with the Up and downstream o2 sensors soon too. I’ll keep everyone posted.

 

Nice! Keep in mind that if you replace everything at once you’ll never really know what fixed it. That would drive me crazy if it happened to me lol

 

Definitely. I’m gonna do everything one at a time with space in between whatever I do.

 

The fact that most all those parts your planning to replace would trip a code if the circuit had a fault.

The OBDII system is working correct ??

best of luck.

 

If the circuit was totally broken, yeah. However the specs that cause a code are so far off nominal specs that that function of obd is effectively useless unless a wire is severed. Look up the specs that would cause a stuck lean or rich code for a 02 sensor, its way way off from spec. Same with mass airflow sensor. So what ends up happening is if a variable output sensor gets lazy or drifts out of spec over time the obd system has no idea.

 

There was a thread where someone had this issue; he did everything to his engine and nothing worked. Turned out, his cat was clogged.

 

Good to know. Definitely feels like something clogged up somewhere. I’ll look into that before putting to much money into too many things. Thanks!

 

I just had an emissions test and passed. Could I still have passed if there was a cat issue or anything up with the o2 sensors?

 

Since you seem to be running in circles on engine issues......have you checked the fluid level in the tranny?

I just did a tranny fluid/filter change on mine. Drained 3 quarts, added back 6.5 quarts. So it was running 3.5 quarts low.

 

If you passed the smog test, its probably not a clogged cat, but I'm only guessing. It also would be a problem both cold and hot.

The symptoms of losing power as the engine warms up sounds like advancing detonation (not quite pinging) causing your ECU to retard timing (but not enough for an engine code)…
-This could be from carbon build up. I know you ran seafoam but I'm skeptical of how well that actually works. A good way to clean your pistons/piston rings without removing the head is to pull you spark plugs and putting some seafoam or marvel mystery oil into the cylinders and use a torque bar to rotate the engine a few times to work it into your piston rings. Let it sit for 24 hours and repeat. Do this for about 3-4 days (or longer or shorter). This is how I got my brother's Honda piston rings unstuck. When you are done, change the oil and fire it up.
-You can try a higher octane gas and see if it goes away

Another issue could be a leaky head gasket that starts to "weep" as the engine metals expand causing poor detonation. You can test this by sending an oil sample to get analyzed for coolant.

Other common issues
-Bad fuel injectors or clogged fuel filter
-Vacuum leaks (the engine runs open cycle when cold and swaps to closed loop when warmer so the vacuum leak wont effect ECU when cold). Exhaust leak would have failed the smog test I think.
-Dirty MAF (see above for open/closed loop operation)​

 

So today I got a CEL on and codes p0446, p0442, and p0441. I had these codes about a month ago and I replaced the aftermarket gas cap with an OEM. Codes cleared until today. In the meantime I passed an emissions test. It’s feeling more rough regularly now with the acceleration hesitation.

 

Yesterday I bought new a vacuum line kit from silconeintakes so I’m gonna change all those this weekend and test the vsv under the hood while I’m at it. According to carfax, the charcoal canister was replaced last year so I feel like it shouldn’t be that and the vsv connected to it.

 

Yeah, you could have a vacuum leak which is affecting your EVAP system. It may not be the EVAP system itself so check all your vacuum lines.

 

Ended up replacing the tps and MAF with no noticeable difference so I put the old ones back and will keep the new ones just to have on hand. Replaced all the vacuum lines under the hood. Nothing noticeable but needed to be done as some looked haggard. I haven’t been able to get the fuel filter off to change it yet the bolts are jammed and I don’t want to break anything.

I’m trying to do a road trip come Xmas so I made an appointment to do the timing belt/water pump with drive belts, coolant flush, idler since it was last done at 108k and has about 160k miles on it since. Once I drove out of the shop I instantly noticed it had peppiness back and just feels more in control when shifting and less tired. It could have just been sorta off with all that. Time will tell but I’m glad I took care of that and needed to be done.

 

Might have jumped a timing tooth...