Intermittent Misfire

This is going to be kinda long winded but i want to explain what i have done and what the problem still is. '99 Tacoma with 3.4 V-6. Replaced coil packs, wires, plugs, gas cap, fuel filter, cleaned Mass air flow sensor, fixed a vacuum leak and still have the misfire. I can delete the codes so i have no Check Engine light and wait until the next day. When i start it it runs great and No light, as long as i am driving. But as soon as a stop it and let it sit a little while when i start it i can feel it is missing and as soon as i start to take off the Check Engine light starts flashing and it runs terrible with a lot of power loss. It does this every time. It isn't a head gasket as that has been checked. So, what am i missing? Can a bad O2 sensor cause this problem. Or what else might it be. ANY and ALL help appreciated.

 

YO
Key term here is intermediate
Had same “whenever got operating temperature “ constant for both our issues

https://www.tacomaworld.com/threads/random-“flash”-of-ce-lite-from-tps.864609/

 

I mean... lets start off with, what codes is it throwing, that you keep just deleting?

It sounds like you're just throwing parts at it and crossing your fingers. It's a good sign that it's not misfiring constantly, but you need a more methodic approach to troubleshooting than the 'ol parts cannon.

 

IiRC
3.4 grounds are firewall/near throttle body and apron near battery

 

It doesn't do it All the time though. Only after it has run a while and up to operating temp.

 

Well i will check all the grounds tomorrow and see it that might be it. So it isn't likely to be a bad O2 sensor?

 

Faulty fuel injectors run fine cold but misfire after you get them warm and shut it off and then restart it. I just went through the same thing with my 2004.

Read this thread.

https://www.tacomaworld.com/threads/injector-psa-v6-3-4l-5vz-fe-1st-gens.730548/

 

Hmm, well, another thing to look into. Thanks

 

Pull the codes to find out exactly which cylinder is misfiring and get you an automotive stethoscope. Then listen to a working injector and compare the sound to the one that is misfiring. It will be an obvious difference between the two.

The working one will make a clacking sound.

$8 BFXM Car Mechanic Stethoscope, Automotive Stethoscope Engine Diagnostic Tool, Automotive Tools Universal for Car Truck SUV Motorcycle RV

https://www.amazon.com/dp/B0D91VMQR6

 

I listened to them and they all tick the same. The code is for an intermittent miss on 3 and 5. Why i thought about head gasket. But in the months i have been driving it i haven't lost a drop of coolant and the oil looks new.

 

3 & 5 plugs looked the same as other 4?

 

I will try listening to them tomorrow both before and after the misfire starts. I didn't look at 3 & 5, i listened to them and 2 others.

 

No rebel…..I meant when you RR’d plugs
(And other parts)
Plugs looked all the same?
U still have them or in the bin?

 

Ohh, yea, the plugs. Yep, i still have them. Will try to remember to look at them tomorrow too.

 

Unfortunately I’m not sure you can get to injectors 3 and 5 with a stethoscope.

 

I did ok. Problem ones are 4-6