hard starting, increasing stalling issue with 04 Taco

Last fall I came across an 02 taco in the bone yard. It had been whacked in the back.
Apparently the po had vac line issues because a number of them had been replaced with nice blue silicone ones.
Sounds like you are chasing a vac issue.

 

I pulled the EGR valve, not sure what I was looking for, just hoping to find something

I cleaned out the body some, I sprayed air thru either port and felt no air coming from the opposite end, if that means anything

I did notice one of the lines was full of rusty water tho

 

I would replace those two little hoses......the upper has been weeping for a while
it'll only get worse

also you have to check the egr port and that temp port in the intake manifold
those can carbon themselves shut


P0401 Egr Flow Insufficient Fixed ! 2.4 tacoma
...........@ 4:15

 

I really appreciate the input everyone

today the truck ran normally, about 80 miles total and no issues - I've had these type of days before I started replacing stuff so I'm not getting my hopes up

I changed out the VSV and just went for a drive, I noticed the LTFT drop from 4.8% (last night's reading) to 3.8% - not sure what else to look for regarding the VSV

I'll keep ya posted and reread some of your comments because I know I missed some stuff

 

@O'Silver_Taco hey thanks for the video, I actually just switched that part out tonight, really hoping that's the issue because that's the part that was clicking loudly every time the truck stalled

 

welp back at square one went out for waffles and the truck started sputtering again like it wanted to stall

 

Did someone stuff a rag or potato up the tailpipe?

 

I thought today would be the day I had good news but alas...

recently replaced the EGR VSV and ECT sensor and today replaced the IAC valve and same shit different story

I'm done

calling a mechanic

thanks again

 

Does this have the electric throttle body? I hate those.

 

@Glamisman

throttle is cable operated

gonna try one last thing, replace the TPS, wish I thought to before considering it is next to the IAC

oh well

 

Should’ve went to a mechanic 3 parts ago. If those didn’t remedy it, do you think that will?

 

Well the 03/04 have a cable to TB but its a lie

the sensor the cable attaches to goes bad.....and the internal motor can go out

how you check any of this I have no ideal....dont even know whats the signs

IF you take it to a mechanic who isnt familiar with 03/04.....they may not have a clue....tell you bunch of crap that aint even right


IN toyotas great wisdom......in those last two years....the cable doesnt open the butterfly.....an electric motor does...
........what could go wrong


https://www.tacomaworld.com/threads...lable-from-toyota.807474/page-2#post-29032053

 

This sounds like something electrical losing power. I have read somewhere in the past about the A/T Temp light flashing during an ECU issue. I know you have said you've already given up and are taking it to a mechanic, but it sounds like a failing relay, poor ground, or power delivery problem that's causing the ECU to intermittently lose stable power, based on all the weird clicking that you mentioned. Have you tried wiggling the key around while its running to see if that does anything? Sometimes the ignition switches do weird things like this when they are failing.

It definitely exhibits symptoms of an intermittent issue related to heat, vibration or maybe corroded/pinched wiring somewhere.

 

oh and I didn't replace the IAC on a whim, I removed it and my electrician friend tested the resistance with a multimeter and got something like 16000 ohms instead of ~14 ohms

got a mobile mechanic on his way now tho

 

mechanic has had it for two days and still has no idea what is wrong

last night he was positive it was related to the fuel pump, wiring etc but after testing everything up to the FP he says it's good

although he said he hasn't checked the FP ground

he noted that the truck ran for 90 minutes with the scanner hooked up, and stalled shortly after he removed the scanner

he doesn't know what to make of the EGR VSV clicking in sync with the AT Temp light flashing after the truck stalls

 

I believe A/T temp light flashing after a stall points to a loss of power to the ECU. Which I could definitely see a VSV clicking on and off during. That ECU is either bad, or you've got a wire getting interrupted momentarily, going to the ECU. I would almost bet money on it.

 

@Fantastic11

just spoke to the mechanic

he said he and his son touched every wiring harness, every ground, everything related to the ecu and said there isn't a single issue

at this point he believes it is in fact a failing ecu

 

Unfortunately wires test fine when they are only intermittently separating like this. A corroded wire can be very tricky to find. I don't know of another way to check it other than opening up the bundles of wire and looking them over. That being said, if it is the ECU, I would open it up and see if there is anything obvious. Like any sign of corrosion or leaky components. Having them repaired can get pricey.

 

hey guys I thought I updated but apparently not:

mechanic replaced ECU early June and she has been ripping ever since, I've done at least 3k miles and went up camping in the Tennessee mountains and ripped the Tail of the Dragon effortlessly

I greatly appreciate any and all insight during this process

 

Parts cannon wins again. If you throw enough parts at it you eventually get it.

The good thing is everything is new or cleaned up.