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

I wonder if we just found our heat soak issue...

 

you're really gonna lose your shit if that insulation was hanging up your throttle and causing all these problems!

 

I don't think it could be just that though, because that liner was actually way worse before the engine swap. It was literally hanging down in lots of places, almost totally unsecured. We mentioned it to the engine guys when we 1st picked the truck up, then when we took it back for the starting issue, they secured it as shown in that pic.

Point being, since it was hanging down even worse before the engine swap was done on the truck, then if it is the culprit, it seems to me it would have had to have caused similar hot start issues before any of this. Right? Obviously we had issues before (piston hole qualifies as an issue!) but seems very different to me than what's happening now.....

But I do wonder if it plays some part here, just not sure how/to what extent....

By the way, glad its amusing for you Hypox! That's what I'm here for!

EDIT: I mentioned this a few posts ago, but so far no one has commented on it. Hoping someone might have an opinion on this:

I've heard the TB and IAC valve gaskets should be REPLACED, not REUSED when cleaning them. So I asked the engine guys which they did when they cleaned our TB & IAC valve, and they said they reused ours. Ya think it could even be as simple as that? We did have the hard warm start issue BEFORE they were cleaned, but maybe cleaning them helped, but then not replacing those gaskets made the problem persist? Gaskets are cheap....would be great to just pick some of those up....

 

Allow me to interject. The liner is there mostly for noise suppression. You will notice it missing only on cold start ups when the fan has not fully disengaged. It will be disturbingly loud, but you will get used to it.

If it is in shitty shape, just get rid of it.

It also makes slamming the hood shutout as loud too. You won't miss it unless you do lots of idling. That's the only time you are going to build up heat to hurt the paint.

 

Sorry about the miss spells. Grilling again...Might have an eye teaming problem

 

I wouldn't think that sorry liner would have anything to to with the hot start issue but I could see it flapping in the breeze, just whipping the heck out of the TPS plug.
Keep in mind that at least half of 1st gens never came with the liner at all and by now a good chunk of the rest have deteriorated into oblivion. Also that thing is fiberglass, it will make your engine itch.
Toyota really skimped on paint under mine, some areas were bare primer.

 

Yea, what he said.

 

Sweet! I'm going with what they said. After all, they are 2 of my 5 trusted advisers.

Husband will be THRILLED to hear this, he's been wanting to rip it out for a good long while, and I'm always like, but what if what if what if....I know, it's hard for you guys to imagine ME reacting that way, right?

EDIT: Which actually would make it quite hilarious if that thing was the issue all along......something tells me he would have some serious "I told ya so" time with me......

Uh oh, let's hope it's not that. Spending $75 on a sensor is better than that

 

Maybe Bama can chime in on this, or maybe I can dig up an old Haynes manual for my '04. On a warm start, you want less choke. How does this work on the 3.4?

So on a warm start, is that when it starts right up if you have the pedal depressed? That kind of makes sense.

It is always a good idea to use new gaskets, but I don't think that would be your warm start problem unless there is some kind of vacuum-controlled actuator that opens the butterfly a little only when warm. Depending on where the vacuum is pulled from, a leaky gasket could keep the vacuum from building enough to open the butterfly. Hmmm. Gaskets are cheap insurance.

Like keakar says, that blanket is more for heat protection of the paint, maybe a little help for the noise. Best to figure out a way to get it secure, but removal is not going to hurt anything but maybe eventually the paint.

 

Thanks TenBeers! Now I have 6 trusted advisers! OK, OK, I'll stop being a smart ass, sorry, couldn't resist........

So on a warm start, is that when it starts right up if you have the pedal depressed? Yes, correct - it ROARS TO LIFE instantly if we continue holding the accelerator down while cranking. Meaning, abnormally fast. Not right for sure. Launch into space type shit.

Thanks for the comments about the gaskets. Hmmm.....might be worth at least looking into removing IAC valve and TB and being 100% sure they are clean/lubed, then reinstall with new gaskets. After we sort out this sensor/connection thing.

Yeah, at this point I don't care much about paint. I mean, I do like the way my beautiful Taco looks, even with all her imperfections, but ah well, that hood liner is knarly. I'm thinking let's get it out of the pic just in case it plays a role, then consider some sort of coating underneath the hood, or perhaps replacing the liner on a brighter, sunnier day - literally and figuratively

 

OK, just thought about it some more, and earlier I said this:

But, in thinking more, it does seem possible that maybe everything now sits just a fraction higher than it used to under the hood (the engine and all the other goodies), then that coupled with the hood closing just a fraction lower than it used to or should, could explain how the miserable liner might not have come in contact enough BEFORE to create an issue, but does now.

OMG yes, I will (how did Hypox put it?) "flip my shit" or something along those lines if a freaking hood liner has ruined our lives for 1.5 months and cost us this much extra $. Wow. Although, as pissed/embarrassed as I would be that my husband and I would miss something that obvious for that long, I would also have to admit how freaking hilarious that would be. Even more hilarious would be the fact that multiple highly skilled mechanics and countless other mechanically inclined neighbors, friends, etc would have missed it. I don't even think I could get mad, I would be laughing too hard. I do NOT know how we'd tell our angel mechanic if it was that. Poor guy. Good grief. We'd almost have to make something really dramatic up, like we swapped the computer ourselves or something.....

So, if everything happens for a reason, WTF would the reason behind this be if the liner is the culprit?

And now I'm wondering if we should rip that thing off, start it, shut it off, then restart it in 30 min before even bothering with any testing. OMG. The reality of this even being possible is slowly sinking in. Wow.

 

Well, it threw a code, so you should at least chase that down -- don't blame it all on that poor old blanket! Occam's Razor comes to mind, though.

 

Just googled that. Yep, for sure.

Oh yes, the poor old blanket. I feel so sorry for the poor old blanket.

Wow. This is blowing my mind guys. We'll know soon! Just talked to husband, he promised he'll be home at 5:30 - we'll rip that poor sweet innocent blanket down, start it, then do our usual obligatory 30 min wait to start again. If still issues at that point, we're busting out the neighbor's fancy voltmeter thing. If no issues, I'm going to have to simultaneously have a serious party while confessing MY MOST EMBARRASSING SITUATION EVER ON THE INTERNET.

EDIT: I'm betting the thread will receive plenty o' traffic tonight, what do you guys think? The drama just turned up a bit more than a notch..........

 

not to side track the discussion, but in the interest of being accurate with info given here, I feel the need to reply. it has been used for noise way back in the past with older cars but in todays vehicles it is used only for heat insulation to protect the paint and help the engine warm up in cold conditions.

let me start by saying this is one of those questions where people will believe what they want to believe but....

In many cases the underhood insulation was first used under the hoods of luxury make vehicles. In the earlier times where the hood lines were high and there was much more under hood air space, the basic orientation might have been to decrease the noise under the hood. It could also have decreaesed the oil can effect of the hood sheet metal in some instances also.

By the 1960s, when hood lines were lower and underhood air space was minimized from what it was in the earlier decades, the heat issue also started surfacing. With the decreased distance between the hood and the engine, there was no space for convection cooling of the stopped engine.

This is what the engineers call "hot soak" and could lead to hot restart situations where the gas tended to evaporate from the float bowl from the more sustained heat periods. If the engine was not running, there was no air circulation under there unless it was from outside breezes.

Being that GM did not put body paint on the undersides of the hoods, they were typically primer black. It's simple physics that black, especially satin black, absorbs heat. If the other side of the sheet metal is painted, that's where the heat will be dissipated to the atmosphere--just as the defroster does to the windshield to melt ice on a winter day.

In that situation, the fiberglass insulation is definitely heat insulation and can save the paint on the top outside areas of the hood panel.

In my younger years, I suspected it was just for sound insulation also. A GM service manager as well as a Ford service manager both agreed that it was heat insulation and its main purpose in addition to the added sound deadening was that it made the paint on the hood last longer. I thought that was a little suspect until I started noticing that cars without the hood insulator pad, did indeed have paint problems many years down the line that was definitely not in any way related to how the paint was cared for as they aged in the sun.

 

If I'm hearing you correctly, you are saying the liner serves 2 purposes:

1) sound reduction
2) preserve paint on hood

Are those the only 2 purposes it serves in your opinion?

I agree about the paint - our Civic has no liner, and the paint looks awful. But, that car is 22 years old. And I could care less about how it looks. It starts and it gets us from point A to B every time, all the time.

I could also care less about sound reduction.

But if there's some other purpose being served by the liner, I'd love to hear it - not being a smart ass, I really would. Cuz we're about to rip it down, so speak now Keakar!!

 

Both of my tacos never had the hood blanket from the factory. On one of the trucks I do lots of idling(mostly in winter though). On both rigs even the under hood paint is still perfect. It will not cause any issues if you feel you want to remove it.

 

all good points. at 17 years old,i'm mor4e worried about the material coming free and wrapping itselfr up in the belts.

My SR5 went 275k without the the liner. I bought the wrecked truck with 26k on the clock and went the rest of its life without the liner. It was much louder without the liner, but not enough to bother me.

My wife has the same truck, but not and SR5. Her truck is still driven every day and it never came with the liner.

Honestly, I think we are spending too much time on arguing about liners and not enough time about the real probolem...I don't know if the liner is the issue with the hot starts, but it wasn't doing it befor the engine change.

Don't think I'm sounding pissy, I just don't have enough time to send out a politacally correct post. Wife and I have some alone time planned and I gotta go!

 

ya its not that big of a deal one way or the other, it most likely wont show evidence of the effects of not having one until its like 15 years old or so and if its garage kept that makes up for a lot in paint life so the main people to notice this are trucks left out in the sun all the time and around year 15 have to think if the want to spend the money to get the truck repainted because of that faded out hood.

those are the only two that I am aware of that can be confirmed through dealer representatives. lots of times things work out to have unintended benefits for other stuff. and just to be clear, I don't think the liner can have anything to do with your problems at all so its just about if its ugly and bothers you enough to rip it out.

and just to clarify for those who think its not to protect the hood from engine heat just because your paint hasn't faded in two or three years with no insulation, what they mean by protection the paint is 10 or 12 years later the paint will be faded more then in other areas and often it will be faded in a pattern to resemble the hood bracing and in the newest vehicles it often shows up first in the form of faded white or peeling clear coat on the hood but its not something that happens right away. its something that can be the differences in needing a paint job because of the faded out hood or not in a very old paint job. for the average person who wont keep the vehicle for 15 years after removing the insulation, they wont notice it but the person that buys the truck will have to live with faded paint because of it.

 

Gotcha K, sounds good, well deserved I'm sure, have fun!

Just ripped the liner down and started it. It's warming up now, then we'll shut off and restart at 30 min, just in case the liner alone is the culprit. Besides, this will give hubby time to review all the notes you guys have shared all day (thank you!) about testing, etc, plus review his FSM notes again. This way, if excessive cranking without liner in 30 min, he'll be armed and ready for test mode.

I'm thinking it's not the liner alone. He stared at the throttle cables under the hood while I revved the engine slowly and consistently. I watched the TPS on the Scan Gauge. The TPS on the SG only went from 10 to 14 while I was laying fairly heavy on the accelerator, which seemed not right to me. And he noticed that one of the cables seems loose. Thinking test mode will be happening, so now hoping for just a simple sensor swap rather than all that circuit stuff - DP and Bama know how that's my fave!

 

You should be able to do the SG throttle position reading with the engine off and the key in the "ignition on" position. This way you can slowly/smoothly advance the throttle all the way without blowing it up.