tacoma no power, misfiring, hesitating

Just read Devinzz1 post. It looks like I'm mistaken on the cooling aspect of the pump. I thought it was more the little electric motor on the pump that burned up, not the pump itself. Learn something new everyday.

 

the motor doesnt actually sit up against casing. internally its already surrounded by fuel.

 

Low on fuel ,possibly condensation in fuel tank due to freezing & warming Temp changes .Your video shows snow banks w/ melting puddles of water- My truck ran the same way this winter - Dry gas or seafoam w/ 5 gals fresh gas cleared up-No problems since. Just an idea.

 

50 years as a scientist and engineer, -and- toyota owner...but what do I know ?

 

http://www.tacomahq.com/643/toyota-tacoma-fuel-pump-replacement-failure/

 

Found a really good web page that supports this statement. At the same time they present the argument that lower gas level in tank causes the pump to work harder. And they also explained how more modern systems with no return line also are more susceptible to pump failure. Really good reading and well made diagrams to help me see what was going on better. I see what Devinzz1 was saying now about the pump module internals always having flowing gas through it.

http://www.agcoauto.com/content/news/p2_articleid/195

 

we had a day above freezing yesterday and the trucks symptoms have disappeared. i have another tps but have not yet installed it.

 

Weird. So what are you thinking, that it's on it's way out? Hence the functioning or not dependant on temperature?

 

truck unfixed itself again today after working fine since last post. same symptoms but worse. was driving down road and symptoms were instant (didnt progressively get worse). truck wont idle right or even rev with no load. shuts off in gear and sounds like it backfires through intake. exhaust smells like lots of unburnt gas. only thing that works is wot (had to drive it to a buddys constantly flooring it lmao).

tps, maf, timing, fuel pressure, and o2 sensor check out okay. symptoms affect all cylinders so i assume coils check out aswell.

otw to buddys house truck started working fine again for a few minutes and went back to acting up after.

will update when rain lets up and i get a chance to look at.

 

No power and hesitating, I'd expect this on a third gen not a first. Like a few said maybe coil, or MAF sensor.

Edit just saw the MAF sensor was good

 

Maybe already said but since it's cheap have you tried replacing fuel filters?

 

My fuel pump ran until it didn't, changed it at 300k. Twice my truck has has ran rough and both times it threw a lean left bank code (Autozone). One was from a bad coil the other from a mass air flow sensor,both identified when my mechanic ran the truck under load with testing equipment hooked up. Mass air flow was cleaned and seems to be fine now although not perfect, probable have to change it eventually.

 

Still no MIL right? Odd. If it's backfiring up through the intake, can it be a timing issue? Or running rich issue? Injectors check out okay?

 

cel is on for no cat. been kinda like a mini hurricane here for past few days and truck is parked out of town. Very well could be an ignition timing problem (cam or crank sensor cause?) This definitely affects all cylinders and intermittently at that so im kind of stumped. Waiting on my new scanner so i can get a live reading of all sensors.

 

Yeah, gotcha. That'll be a big help to have that scanner and data. Keep us posted on what you find.

 

You said it ran fine one day when it was above freezing, maybe moisture in your gas? But I have to say my 95 Tacoma acted like yours is, would run good then start missing. backfire some times, would over heat the converter, engine light flash, mine turned out to be a cam sensor going bad, don't know if that's your trouble or not but something to check, trouble is when something works part of the time, it may check good when it's not. Good luck.

 

My 2k taco had a leak in the bearing of the water pump which went into the timing belt at ~65k miles. The heat caused the radiator fluid to clump into balls and threw off the timing belt. (A imports mechanic finally troubleshooted for me). My symptom was weak acceleration and slight hesitation while slowly gaining speed.

In the end, he replaced the timing belt and water pump. (And removed all of the hardened balls) Not sure this is your case, but something to know...

 

I think you are on the right track checking the sensor inputs via a scan tool... I think you are going to find a flaky coolant or air temp sensor.

 

went to look at truck today and the thing is running fine again. i got my scanner and and didn't see anything abnormal. got missfire codes for all 6 cylinders and a p0170 code.

anyone know what the timing advance should be?