Currently - 2 leaks at intake mani or valve covers -High/cold idle at 2100 RPMs & delayed warm start

Nope.

 

When mine gets the click, it’s because it’s trying to start normally, all the systems are working as they should, except the plunger never makes contact with the copper contacts in the starter. They’ve worn down over time with each starts minor arcing at the moment of contact. You get the plunger “click”, but no action. When it does make contact, it starts as normal. If I ever get a failed start, sometimes it will long crank following. Not saying yours is the same issue I’ve experienced, just sharing.

 

That’s the only other concern I had. Like, yesterday I got that weird 3sec crank but no fire. Almost like the ECU had closed the circuit for the fuel pump relay by the time I got a turnover. Made me have a doubt as to whether it could be starter.

I’m also not debating whether my knock sensor wiring issue may be related. Like, starter and knock sensor for the later years are all bundled in the same harness run. Maybe the occasional P0328 code and start issue are linked by way of harness problem and/or contact corrosion. I’m really not willing to pop the intake off and dig in at the moment, though. I need to, it’s just not great timing with all the stuff we have planned the next several weeks.

EDIT: FWIW, it appears there's a cheap test for relay. I generally trust Bosch parts, and it appears Bosch part 0986AH0091 aka BCH-0986AH0091 is a direct fit for the '05-'06 (at least for AC). It's $3.77 on RA and $5.99 at Summit versus $25 for the Duralast part at Autozone, or Echlin ECH-AR484 at NAPA which is NLA supposedly. I ordered on RA, $9.77 shipped with my 19¢ coupon code discount. Beats $69 (before tax) for OEM from the stealership and should at least facilitate testing this theory.

 

The fact that you got a cam sensor code one time seems like it has to be at least indirectly related don't you think?

 

OK checked and re-checked the vacuum hoses this morning and all seems fine other than the vent coming from the passenger valve cover into the air supply before the throttle body is not in great shape where it connects just before the throttle body. But I make sure there was no air leaking by squeezing it around the connection with my fingers with no change


I went back and swapped the power steering valve. I'm not sure it really makes any difference which hose is connected in which spot. I could be wrong but I get the same behavior with the hoses in either position. maybe this is a hint? It doesn't seem to do his job no matter which way I have it connected. The idle noticeably drops a few hundred RPM's when you're parked and turn the steering wheel in wither position.

Swapped back to my factory ECU. Not sure exactly how it would behave since the secondary air pump can no longer pump air into the exhaust ports. But the idle behavior was the same. so I can mark that off the list I was really expecting to get a code due to the SAIC tubes being disconnected but did not

While it was still doing the cold start fast idle I disconnected a few of the vacuum hoses that are known to cause idling issues and at most it dropped 100 or 200 RPMs still running at around 1900 or 2000

I'm at a loss of where to turn. Can't find anyone that's had the same symptoms

 

The thought had crossed my mind, but the fact it happened once out of four or five instances, and there was something power-related happening at the time, i.e. I had a jumpstart capacitor attached to the battery, makes me question it. If it happens to throw that code again after, I'll be looking at that.

And shit, I forgot to get you those vacuum hose pics.

 

Good point about the other issue and jumpstart. I thought of that as well.

it's OK on the pictures I think. I watched a few videos of people installing it and they didn't indicate either side mattered. They just hooked them back up, but I could be wrong.

I do know it acts the same no matter which way I have it connected. At first I thought it made a difference, but I've done it enough now that it does not matter at least at this moment with my other issues

also checked MAF sensor. As I expected since it was just replaced a few months ago - clean as a whistle

 

@shifty` I got the same cam sensor code (p0340 iirc) once on my truck. When I let it sit for a few weeks and the battery got weak and needed a jump start.

Maybe you have a corrosion issue or weak battery?

 

i'm hunting down a few of those now. I replaced the PCV valve last week and it's in about the same shape. Trying to get all of the specialty molded ones at once because the shipping seems to stay about the same

I've already replaced the molded and insulated one going to the power steering valve.



PITA the Toyota dealership says one of them doesn't fit my vehicle and it is identical in the image even though I know you can't always trust that. The one they're suggesting is a big hose. It's nothing like what I need.

 

Same cam code. Same condition, had a jump setup. Thinking it's a one-off, same as yours.

All no-start cases (and my knock sensor circuit high) code happened after my alternator self-immolated many years ago. It self-immolated in a NAPA parking lot, after the alternator failed and truck was dying on my way to work, I assumed battery fail, and was wrong, which I realized after I bolted in a brand new NAPA Legend Premium battery, then the fresh volts/amps lit the alternator up. That was about 5 years ago now, so I'm probably over due for a new battery ... though I've always been skeptical of this damn battery since day 1. Voltage has been jumpy ever since I installed it, had these periodic no-start cases, sometimes throw 'circuit high' codes, etc.

Anyway, I'm going to throw one part at a time and watch it. I'll probably start with the battery, just gotta shop around for a good deal.

But I've also seen and shown I have/had some corrosion inside my cables, they didn't test out horribly concerning, but I haven't re-checked for a year or two.

Oh shit. @Weagle not trying to hijack your thread. I keep forgetting where I am.

 

Here were my part numbers from my order, we both have the 2006 2UZ so I assume your part numbers will be the same. I want to say '1' is driver, '2' is passenger, that jibes with your diagram (first 5 of diagram number almost always matches first 5 of part number)

​

 

Confirmed: I just realized as I'm looking at the routing: This makes no sense, the valve is either always-open or always-closed, and when it senses pressure from the PS line it's threaded into, it changes state. This is why, when you pinch the hose, the idle changes; it's simulating the condition of pressure activating the switch. And besides, there's no arrows on the bibs I could see, suggesting directionality, so you'd be at the mercy of the threading of the part to dictate which bib was pointed which way! In my case, the bib closeest to the firewall went up to the intake box. The other went up on top of the throttle body.

 

@Weagle have you tried cold start and wiggling the modified O2 harness. Im thinking it might be related combo of aftermarket modifications. ( both ecu are bumping hi idle in attemp to warm cat's per ulev tuning parameters). Larger diameter collector= less velocity over sensor= need for more airflow to hit "cold start" mandates. O2 tells ecu, we need more egt to warm these puppies up.

I know that only address the high idle. Can you log your 02 voltage on both sides and post?

 

I am hopeful it was at least in part the dirty throttle body. Cold start this morning seemed to be much better

I eliminated the new ECU yesterday

It did not do this with new ECU and other mods, headers, etc before the timing belt change

The ECU mod is designed to work with the headers. This is not part of the known behavior for this particular ECU mod from this vendor


What changed?

1. the "bump" when timing belt cover spacer sleeve seemed to fall between a gear/pulley and the timing belt or the engine body. Visual inspection showed it did not jump time and there was no damage anywhere inside the timing belt covers that I could find. no apparent damage to any wiring The cam sensors are protected so the only other possible sensor would be the crank sensor

2. The truck sat without running for 3 months from mid July to October until I was able and had time to correct and resolve a few issues with timing belt tensioner bracket related issues


Also I did the pinch test for the power steering valve this morning. No detectable difference in the idle.

 

Damn im at a loss. Do you have a mxpro so you can log what sensors are doing. ? Im leaning toward vac leak, im not sure if all the sensors are shut off in open loop or just majority.

 

I do not

i want to see how it behaves from a cold start tomorrow morning. This afternoon after resting for 3 1/2 hours it started and ran at 1500 RPMs then dropped down to 1100 fairly quickly. That's a big difference

if it starts like that in the morning, then I may be down to the power steering air control valve or related vacuum hoses. When I pinched that vacuum hose earlier today, it had no effect on the idle so there could definitely be a vacuum leak there or bad valve

keeping my fingers crossed that I'm getting close

 

I think you will get it. In open loop, mine runs at around 1000rpm maybe 1100 during cold start. Only reason i inquired about mxpro is many tuners " turn off" closed loop to get around emissions related codes as ecu is running blind. But I dont think this is your issue as its been dropping as your addressing things. However, it would help narrow down the exact cause. Open loop logging will look like a flat line ( sensors off), closed loop something like this , where you see ecu adjusting per sensor input. Many tuners make " mild adjustments" to open look tune
And send off. " set cold start parameter, set target afr, timing chart etc" , its not a bad thing. But not good if your changing elevations. Its like measuring by pacing it out w feet vs using a measuring wheel. A quick log of you vac readings would confirm or remove speculation of vav leak.
Example of closed loop operation: ( me passing slow moving vehicle on hwy)

 

And remember w yota' high voltage is rich, low is lean. Im speculating, but maybe air injection system delete kit plays a small part. Afr sensor logs are invert of O2 sensor logs. Do you have a 3 way "T" to tap into vac lines? You could mechanically test your vaccuum readings...atleast during hi-idle condition

I think you make have it figured out. Your TB may have been " ajare" i would clean all sensors / seafoam/ clean. Re-set ecu. See how she runs.

 

Thanks for that video you sent. Always helps me to know how it all actually works. I subscribed his channel. I'm calling that first one o2 and air fuel sensors for dummies like me. That was a good tip on the brake fluid as well


I already cleaned the the crank sensor when I was in there the last time. probably pull out the cam sensors and clean them while I work through this too

 

Update:

I still think I have a vacuum leak and the power steering air control valve may be bad which by what you guys have told me could make a 200rpm difference. Once it gets warm it's idling at about 7500.

I believe the throttle body cleaning took care of it

Cold start this morning. It did briefly jump up to 2100. I know the tundras have a surge when you crank them. But this morning it very quickly dropped down to 1500 and then within a few seconds got down to 1100. Previously, it stayed above 2000 for maybe 10 seconds or more And very slowly and stubbornly dropped. And previously if you tapped the accelerator it would jump right back up to 2100 and stay instead of dropping down further


Much more acceptable and maybe a vacuum leak is the last piece of the puzzle. Hopefully.

 

I am going to try this again. I did it a few weeks back before the throttle body cleaning and it did seem to make the throttle response smoother (less delay) and more responsive. The ECU tune also improved throttle response as it was designed

 

Thats awesome! Well played! Looks like you removed quite a bit of Gunk. !

 

Update:

I replaced the power steering air control valve along with a few terribly dry rotted vacuum hoses and the fast idle on a cold start to improved. It drops much quicker, but it still starting off too high

I just did a smoke test. Smoke is coming out around the top of the valve covers on both side, but it is worse on the passenger side. It's really hard to tell definitively but I think it is from the valve cover gaskets

the smoke starts coming out so thick I had to turn it off and let it clear and try to catch it when the first wisp of smoke came out. I can't imagine this being related to the long warm start, but could it be affecting the idle on a cold start?





passenger side. It's hard to see without making a video, but that in the circle is the first wisp of smoke



ditto on the driver's side






I know this would not be ideal, but since it seems to be just a very small section on each side, could I do a temporary plug fix with some RTV?

 

Did you change the valve cover gaskets out?

 

I have not. They have been replaced once by the shop. And I recently thought they were leaking, but then upon further inspection, it appears to be the two gaskets with the oil filter bracket

since I have not personally taken the top stuff (intake manifold or valve covers) off on this truck before I'm not sure what else could be the source of the leak

I was able to get this picture and there definitely appears to be some oil gunk buildup on the driver side. There was no way to get a good view of the passenger side

 

I guess I'm really just need to take some of the hoses and wiring harnesses off of the top so I can see if the source is the intake manifold gasket or the valve cover gaskets

 

I can't remember if I responded to this after I replaced that air control valve. But it did seem to drop it about 20%.

that was an improvement, but it is still too high as compared to early last summer after header install. I remember specifically because one of the vacuum hoses fell off and the idle was extremely rough and when I reconnected it, it then consistently started at 1800 RPMs and then dropped quickly and was very smooth