Toyota Tacoma starting issue

I think we established that it is cranking but not starting so why go after the starter circuit?

 

If I am understanding correctly:

Once running, it runs fine, but once stops, it will not restart until it sits (cools down).
It CRANKS - the starter is able to turn the engine, but it doesn't START
You used to be able to pop the clutch to start, but over time, that has now failed to work (I assume it became progressively worse?)

I vote for crankshaft or camshaft position sensor.

Assuming #2 above, I don't think it's the starter/circuit.
It COULD be ignition related, but it seems engine temp related so I would PERSONALLY think you would have ignition problems even before you shut the engine off (ie. it wouldn't run fine UNTIL you shut it off).

Crankshaft/camshaft position sensors have been known to cause the symptoms described as they deteriorate (when hot the hall effect gets erratic), which matches how you lost the ability to start by popping the clutch to the point where even that doesn't work$.

That's my $0.02 for what it's worth (my wife think it's worth $0.002).

 

You’re correct, I missed it.

 

How you making out?

 

Yeah I'm having exact same problem......but 4 banger world.....I have a 98 2.7/2.4 auto...

Just randomly wont start......use to be after sitting for an hour...

Then just today it sit for 4 hours and would just crank ....no start...

Everything on the truck is less than 3 yrs old.........motor and block just hit 19K....

All new sensors /coils/ injectors, maf, ect, iac, cam / clank sensor, ....new O2's
All new headers, cat, walker exhaust...

everything is new oem where posible........except its got its original neutral safety switch.....this is an auto a43D...

All new silicone vac hoses......on everything..

couple years no problems then couple weeks ago this all started

Ive done new plugs, new maf, battery clean and scan good...

I get no codes........I have -5 LTF trim at idle/ +10 at cruise....
Cold air intake w outside air feed....no cel's

Use to be messing with bat cables I could get running again..
but really justs letting it set until it wants to fire up......hour or two later...
when it do start....no cough or stuggle.....just fires right up, like you flipped a switch.

Last time I jiggle the ecm connectors to get to fire up.......but who knows next time...do I have something going out...

I have a spare everything so I can try anything...
even a spare ecm......

everything is new on the truck.....even all the fluids and hoses.....
even my grounds are heavy duty and over kill....
coils are year old denso's....
fuel pump is 1 yr old denso.
starter is 2 yrs old....

When I test crank with a hose off the fuel reg....it comes pouring out...
so its not pump or its circuit thats suspect.....

Could the egr valve be stuck open?,,,,,,,at different times


Only real guess I have left is swap out ecm......

or maybe when the new motor was put in the crank sensor somehow got damaged.........I actually have a brandnew denso one in the bag....
but it is a super PIA to pull that alt bracket off to get to that on the block....
half day job on a hail marry guess....
........but I'm essentially beached right now....

 

You would probably get better assistance in the forum for 1998 Tacoma's... This is a Second Generation Forum.

 

Post in the 1st gen, as there's quite a bit of differences. In the mean time, you didn't say if you checked fuel pressure.

 

I wonder if a scanner that could read timing advance would be of use in determining whether the crank/cam sensors are workin.

 

Are you getting an RPM reading on the tach or scan tool when this happens?

 

Yeah at idle I get 8 ~12 advance on cyl one

I'll run livedata tomorrow and check rpm........bet you it reads just fine..
just like the maf.....right at or below 3 g/s at idle on a 2.4.....

 

Yeah I'll move this over to 1st gens........this was most recent event I could find matching mine...

Was hoping someone had some insight......dont care who

the 4 bangers are almost identical......except of course for the VVT...

your save today, may save your own ass tomorrow.....

 

@O'Silver_Taco you're in deep, man.. been there. did anything get done around the time your fault started?

If you wanna chase some nutty ideas I've got a couple. One is if you rewired your harness using any kind of non-standard wire. the other is.. maybe a failing fuel pressure regulator? not sure that lines up..

Another consideration, if we're thinking electrical -- heat increases resistance, yeah? so perhaps damaged wiring.. does yours have a fusible link?
I really don't have the brains/experience with high tech scanners, but if you want a bulk bin worth of iffy ideas, shoot me a PM. I'll keep scratching my head.

 

No changes lately.

Year ago the ignition switch was going bad and would blow the am2 fuse over and over until I replaced it.
Thats when the coils got replaced chasing that..

Otherwise over last 2yrs turn key start.....dont even have to give it any gas.


Harness has no splices and in good shape...

FP reg works fine.....spews fuel out of the FP reg return hose when u crank..

And dont think its heat related.......last time set for 4 hours....no fire... set another 1/2 hour, fired right up...

last week sat all nite and morning no fire.....until I messed with it for couple hours...

pulled and pluged the brake booster line.....and it started right up...

tried that today......was still a no go ....until I took the dash apart and wiggled the ecm connections...

Was that the fix......I doubt it.....

I've been starting it over and over at home this eve......it will do fine until the next time..
maybe 8 or 9 good ones.....before the next no start..

I'm worried eventually it wont start at all...

And I dont have any choice.....I keep sticking until the beast is dead....
not fearful......Im pissed......I must find the offender....