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

Thanks for making time to read/chime in Matt, I really appreciate it. I know you're super busy, thanks again buddy

 

This thread is about folks with 2.4's and 2.7's that have hot start issues. The 4th to last post says:

"I fixed mine by doing my valve shims... The clearances were too tight. They get tighter as valves seat more into the aluminum head on time. So when they were hot the valves were tight enough that it affected starting."

Do you guys think this could be our problem?

 

wouldn't hydraulic lifters more than compensate for this?

 

this is eric. i wonder if we did a bypass hose around the fuel filter (take it out of the picture) just to see what happens. the filter on there now was installed with the "new" engine, and it is aftermarket (not factory).

 

Hi everybody today was awesomely unsuccessful! Overview is: no tight valves found during valve clearance check, swapped injectors are not correct for vehicle and no results could be taken using them, and no problems found with the original injectors

Now for the details and the pictures ..

The patient is on the table.. inspecting valve clearance. I found no overly tight valves. Some were .001-.002 tighter than the spec limit but from experience this does not mean anything at all. I have seen tight valves before 3vz 3.0L that were hanging open and causing a problem. They looked very different they were very small clearance to no clearance at all aka could not fit .0015 feeler gauge in. These valves do not look like that at all I would give them a pass for the class. I have all the clearance specs that I measured but they are on a piece of paper at work



The injectors in the truck are the silver colored ones. The spare set of known good injectors are the brown colored ones. I guess there is a split in late 1998 where Toyota decided to change the injectors (and the ecm). The spare set I have are the later ones. I thought what the heck I will give them a try maybe they will work. The intake manifold and
fuel rail remained unchanged through the injector change so I was hopeful. BTW if you are ever thinking of doing this... DON'T. It doesn't work




Here are the known good injector installed...




.. And here is the immediate -14.88 sft. This means the new injectors are spraying a lot more fuel and causing a problem. So I idled the truck a bit and just called it a fail. Going back to the original injectors.



Here are the original (silver) injectors on the testing machine at my work



Note the little red light is on over "leakage test" this indicates that this is a leakage test (I'm tired)



Here is the leakage test in action. The machine has a 60 second timer for this test (not adjustable). So I ran the test twice. I did not see a drip from any injector during this test.



This is the ultrasonic cleaning in simple green solution. From experience this does a really good job cleaning the injectors and will clean up fuel trim hugely if the injectors are dirty or clogged.



So one step foreword two steps back, I would like the problem to jump out at me any time now. Going to put the old injectors back in and......um......when I think of something else to test I will do that

 

https://www.youtube.com/watch?v=sy13Ug_PXwk&feature=youtu.be

 

I haven't read thru all 134 pages, just bounced around here and there. But has the ECM been changed out for a known good one. Also is it a corroded terminal / grounding issue? I have chased fuel/starting issues for months on my 1998 4runner 5vz after a rebuild. I ran my self ragged looking and checking things, but I was installing a radio in the 4runner and somehow blew the 60amp fuse in the fuse holder under the hood. While I had the fuse holder apart I pulled all the wiring out and checked the wiring out, I found one of the terminals on the ECM fuse slighty corroded and burnt. It was not something you could see from above and only found it by accident installing the radio. It tested fine on voltage, I guessing after the fuse got hot it would cause problems I cleaned the terminal and fixed the burnt wiring, soldered all the other terminal for chits and giggles. I upgraded the big 3 wiring and cleaned all the grounds and it worked correctly after that. Just something to look at. Any kind of electrical short/corrosion/bad connection can play havoc on the ECM and other onboard computers. Just some food for thought.

 

I think we have a cylinder head issue...no tight valves, terrible leak down test numbers, I suspect valves are sticking and this requires a top end tear down.

It is time to take action with the shop who installed the motor...

Howard

 

Hmm. Well, unless there is a spark issue, I am out of ideas for now. Unless the heat affects the injectors, and one of them leaks only when hot. Possibility, but a longshot.

 

But even if this was the case, we would not go back to them. Basically, we would not go back to them if our lives depended on it. So I really don't know what the hell we'd do if something this involved needs to happen with the engine. I'm sure the labor time it would take to do a "top end tear down" is no small amount. I am going to try to remain calm about the engine concerns until I hear more on the subject from Jayman & Noahpete though, as they've got hands on the truck and clearly know what the heck they are doing/talking about, so I'll hold off on pushing the "Jen's engine panic button" just yet. Well, I will try......

PS: Don't worry though hetkind, we won't let them just take advantage of us without at least trying to do something about it/recover something for ourselves. We just won't let them touch the Taco again. But our #1 focus is getting the Taco fixed, so the other part can wait for the time being.....

 

Once again, we are stunned at how hard you are working to not only perform important testing on the Taco, but also how you are managing to find time to do such an awesome job documenting your findings with photos, videos, etc - thank you!! We just couldn't feel luckier that our beloved truck is in your hands Noahpete - your commitment to problem solving and attention to detail in doing so is inspiring! And we can't tell you how cool it is for us to see your posts pop up each evening and learn all of this super informative stuff about our truck and how it's behaving! I'm not sure how we will ever be able to thank you enough

I'm sorry the injectors didn't reveal themselves to be the culprit, and that the spare set was a different size. That must have been so super frustrating - thank you so much for hanging in there though and continuing to chisel away at the mystery!! You are going to get this, and there's no rush either, we are doing just fine with our little Civic.

Hope the truck behaves better for you today!! Good luck Jay, and thank you!!

 

At this point in time Eric, you could definitely try that, "Just to see what happens". Go for it. I wouldn't drive it for any long length of time set up like that, but for testing purposes, yes.

For the current mech's: Was the engine cold 0psi residual overnight pressure (or loss of) replicated again?,,or just that one time?.

 

Noahpete, just to let ya know, we'd totally be up for spending the $ to replace that fuel filter with a Toyota one unless you are opposed to it for any reason. We'd actually planned to do that ourselves a week or so ago, just never got around to it, but I'd called for a price and I know they aren't much at all. We thought we were getting a Bosch when it was replaced, but afterwards found out it was an aftermarket (OP Parts), which I've heard is kind of a generic/junk brand.

Just knowing it was one other thing that was changed on the vehicle at the same time the hard starting began makes me question it......

EDIT: Should read: "that was changed on the patient" Thanks for treating the Taco with such care

 

A guy on this thread (nissanh) seemed to think replacing his Bank 1 Sensor 1 O2 (before cat) helped his extended crank time problem. We'd be open to replacing those two O2s as well, if you guys thought it was worth trying. But it seems strange that it could be O2s, because I've been told by others that since they don't report info while the truck is in open loop (which it would be during cranking, right?), that they shouldn't cause an issue with starting. Is that correct?

 

Jen. The fact that you use the term "open loop" is impressive to me. Get the chic some wrenches, its time to put her to work.

I do not see a reason to replace the fuel filter.

 

Aw, thanks man!! I owe it all to these smart TW dudes for lurnin' me these past 4 months on everything from piston holes to injector maintenance! And I also owe it to considerate mechanics like you guys for somehow managing to find the time to educate your customers about how their vehicle works, even after doing a stellar job working hard on diagnosing it for them!

We are totally fine with whatever you guys think on the filter. Just thought maybe there was a chance it was faulty, or somehow improperly installed or something......saw a few threads (not necessarily Toyota specific though) that said they had an extended cranking problem after changing their fuel filter....although you can find damn near anything to support a theory on the internet if you try hard enough!

 

Should have also added: both O2s are original to the truck as far as we know, or have a minimum of 130K on them (we bought it w/70K, it has 200K now, we've never replaced them). We'd planned to replace them a few weeks ago then changed our mind because a previous mechanic felt pretty sure they couldn't be the problem. Just FYI, FWIW

 

Update for today Thursday 4/23/15: Re-installed original injectors




Here are the valve clearance specs that I measured yesterday --

Valve Clearance:

Spec: (cold) .006-.009 in Intake, .011-.014 in Exhaust

Cylinder 1: Exhaust .010 .011, Intake .007 .005

Cylinder 3: Exhaust .010 .009, Intake .009 .007

Cylinder 5: Exhaust .008 .009, Intake .008 .008

--------------------

Cylinder 2: Exhaust .010 .009, Intake .007 .011

Cylinder 4: Exhaust .010 .011, Intake .009 .008

Cylinder 6: Exhaust .011 .009, Intake .009 .008

 

No hydraulic lifters. This is an overhead cam system with buckets.

From what I am seeing on these number, #5 has slightly too much clearance. This would result in a slightly shorter valve opening time, thus reducing pressure in the cylinder. Other than that, the clearances look good.

 

But a slightly tight or loose valve won't affect leak down numbers since those are done at TDC for EACH cylinder...What the valve adjustment numbers tell ME is that even with the valves completely closed, we are loosing a large amount of air through the valves. It appears to be a piss poor valve job. No way to fix that without pulling off the top end of the engine.

Howard