SOLVED! Post 2853 Leaking Injectors, Dealer Techs Rock! Extended Cranking after Engine Swap 3.4L 5vz

It could/should easily be concerning and with good reason like a bad ECU. A CEL should have been set at least for a misfire on cylinder # so &so. The misfire detection capability is extremely sensitive and will pick up misfires that you would never notice. The ECU can "tell" from extremely small variations in the signal from the crank shaft position sensor that things are not happening, be it due to fuel, spark or compression.

Short of being submerged or set on fire the ECU is extremely reliable. They do fail on occasion but it's rare. Are you folks the original owners?
Then there is what's known as 2 trip logic. For some issues the ECU must see several instances of a problem before it sets a CEL. It sort of "makes sure" before it alerts some crazy lady. I can see you folks missing it in the confusion or a battery disconnect. Maybe just the exact timing of the events, start and stop cycles of the engine and distance driven were not quite there, I just don't know. I should think that a misfire condition would be quick to set a CEL because unburned fuel can incinerate a catalytic converter in no time.

 

UPDATE, NEED ADVICE FAST PLEASE!!!!!

 

Guy just called, said our ECU is fine. He said kind of what DP just said, about the ECU needing 3 cycles of a problem before it sets a cel

 

He thinks our ECU is fine

 

He said he has a $7K scan tool that didn't detect a single thing wrong and said on older models like ours a lot of times they don't monitor the injectors, so it could be why no CEL when plug gave up

 

He thinks the plug gave up and the hole occurred in an instant all together, then I shut the truck off in a few moments after and truck didn't have a chance to register that there was an issue

 

PLEASE TELL ME IF THIS SEEMS LOGICAL because he repeated his test after repairing the fuel hose leak and is getting results that tell him to replace the pump

 

I'm about to order the pump but first want to know if I should take to dealer to somehow be sure our ECU is fine first, as we might cut our losses if ECU is bad

 

I trust this guy, I really do, he's a master mechanic and worked for toyota, i trust the quality of his scan/computer tool......but clearly I was at least somewhat misled by the engine guy so am weary of blindly trusting anything at this point

 

ANYONE? He also said he's only seen 2 ECUs ever go bad on a Toyota - that Toyota and Honda computers are known to be the best out there

 

Well, if the fuel rail regulator slams shut after a few psi(down to 43?) drop off,,basically as soon as the key is shut ,,then the check valve in the pump closes when it should, That return leak shouldn't matter on the starts.

You have to have the injector side fuel line loaded with a head of fuel, ready to go, as soon as the engine cranks. It's bleeding off after a heat soak. It might not be the pump again, but check valving on the pump stem area,,a pressure side leak,,bleeding off that pressure load of fuel that should be held in that line for the next start,,hot or cold. Hell, it might work just fine in the hot summer. Maybe better. Hot summer, hot bottom of the tank of fuel left. Heat causes expansion of metals and some plastics,,stuff works smoother then sometimes, that sort of thing.

But yes, fix the return leak ASAP, absolutely,,glad it was found. And if it fixes the problem,,then hell yes and slam a beer or two.

No need to kill this thread,,don't think you can. To much good stuff in one. Would be a shame to.

 

But should I trust him regarding the ECU being OK????????????

 

I believe him 100% about the pump, not worried about that at all, worried about spending $200+ on pump and then finding out bad ECU after all

 

Sorry, I wasn't very clear in my spaz mode, trying to order pump before 3:30, but nervous about the lack of CEL - wanted to see if you guys thought his explanation about why no CEL during piston hole made sense and we should have faith in ECU being OK

DP, I KNOW FOR SURE we did not miss a CEL

 

Yes, logical and good news. Your year does not monitor injectors per say, but it does monitor misfire conditions. There is a separate trouble code for misfire on each individual cylinder and one for "random" misfire across the board regardless of the cause. It's likely what we said about the timing/duration etc of the whole (destruction) event that just fell short of the parameters for a CEL.

 

Guys? Would you go ahead w/the pump and trust the ECU being fine explanation?

 

ORDERING PUMP NOW!!! THANK YOU!!!!!!!!!!

 

On hold w/parts guy.......

Thank you for hanging with me guys, especially during these crunch times!

Looking like maybe, just maybe, we are finally on the home stretch of this nightmare!!!

Ordering pump/strainer Denso kit from local shop, they can have it later today or tomorrow morning at the latest for an extra $35 over R. Auto, plus local so if wrong part comes, they deal with it

Ordering gasket seal thing from my fave dealer that incorrectly diagnosed problem in the first place, cuz that was the only local place that could get it in a hurry, should have that tomorrow......bonus, same price as Rock Auto on that one! Never happens!

 

Thanks Mod! So you want the thread to live on, huh? Ready for some wheel bearing fun? Looking like we'll be heading there next......pump & strainer & gasket should be ready tomorrow/Friday AM at the latest, AND IT SOUNDS LIKE OUR ECU IS FINE!!!!!! He also said if ECU was bad, our truck would be doing some seriously weird shit, and he sees no signs of that at all. I told him about the dying clock and the passenger window being stubborn sometimes, he said those are not controlled by the ECU on our truck.........sounds like it might actually FINALLY FINALLY FINALLY be time to do the happy dance, woo hoo!!!!!!! Keep the thread alive, hell yeah!! Thanks Taco World dudes!

 

bottom line, with the age and mileage on your truck it wouldn't hurt to replace the pump weather it needed it or not because it WILL fail at some point so look at it as preventative maint and it might just be your problem.

you can not be wrong to replace the pump even if its not the problem.