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How to set ignition timing on 2003 Toyota Sienna?


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Alex Ethridge
User

Aug 6, 2011, 10:06 PM

Post #1 of 19 (5192 views)
  post locked   How to set ignition timing on 2003 Toyota Sienna?  

Is there a way to set the ignition timing on a 2003 Toyota Sienna or has all of that been disabled by all the computerization of cars these days?


Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 5:55 AM

Post #2 of 19 (5178 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

There is no ignition timing to set. Don't worry about it.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Alex Ethridge
User

Aug 7, 2011, 7:06 AM

Post #3 of 19 (5171 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

I can't accept the "Don't worry about it" part as I know from my 48 years of doing my own mechanic work, including boring blocks and complete engine overhauls, that the timing is off. I have a "feel" for things like this.

My 03 Sienna CE with only 8192 miles (yes 8K, not 80) on it is giving me 17 MPG and less pep than my two 01 Siennas with over 170,000 miles on both that give me 22 MPG. Last night the 03 Sienna had an intermittent timing incident. I accelerated from a traffic light and had gross loss of power; but, all cylinders were firing consistently. The incident lasted for about a quarter minute and corrected itself.

The evidence is there for a timing problem and maybe an engine computer problem.

Is there no way even a professional mechanic with the proper equipment can adjust the timing?


Link from Toyota forum removed


(This post was edited by Hammer Time on Aug 7, 2011, 7:41 AM)


Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 7:41 AM

Post #4 of 19 (5166 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  


Quote
I can't accept the "Don't worry about it" part as I know from my 48 years of doing my own mechanic work, including boring blocks and complete engine overhauls, that the timing is off. I have a "feel" for things like this.



I'm sorry but you have absolutely no clue what you are talking about. This is a computer controlled, fuel injected car, not your old Chevy with a carburetor. The ignition timing is permanently engineered through the use of a crankshaft Position sensor and cannot be changed. Your car doesn't even have a distributor so how do you think you're going to change the timing?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Alex Ethridge
User

Aug 7, 2011, 8:17 AM

Post #5 of 19 (5158 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

"doesn't even have a distributor so how do you think you're going to change the timing?"

Thanks for your comments. I don't know and that is why I'm here asking.

I am fully aware of all of that; but, I also know that the timing is controlled by a computer. Computers are notorious for screwing up, including computers in cars. (Remember the Toyota elusive acceleration problem -- and the coverup?) Computers can have their firmware and software changed/corrected/adjusted when files/firmware/software become corrupt or otherwise out of order.

So, are you suggesting that the part that needs to be replaced is the car, itself to correct an MPG problem? I hope not.

I'll be checking the timing on it some time this week, maybe today and I'm sure I'm going to find it is retarded to some degree. If the timing is not off, I'll know I need to look elsewhere. I'll get back with my result. With a five-mile difference between the mileage I'm getting and the mileage I should get, the difference in fuel costs will easily exceed 10,000 dollars over the life of the car and that's a ridiculous amount to just sit back and give up for. I'm not such a big fan of Big Oil that I care to make a donation like that.


Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 9:57 AM

Post #6 of 19 (5153 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

I'm afraid you just need to sit back in your rocking chair and leave the diagnostics to someone that hasn't been left in the dust by technology. You really have no clue what you are doing and just may do some serious damage to the electronics in your car.

PS, The was never any cover up or computer failure proven with Toyota vehicles so again you have no clue about what you are talking about.


http://www.huffingtonpost.com/...tronic_n_820364.html



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Sidom
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Aug 7, 2011, 3:20 PM

Post #7 of 19 (5148 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Alex... I just checked the mpg on your Toyota. Its 17 in the city 19 combined & 23 highway.

We're talking a few miles a gallon here and while there could be a problem going on causing reduced mileage, you may also be chasing ghosts... 1st just because one car gets a certain mpg, this doesn't mean they are all going to get that.

There is so many factors that can affect your mileage. Low tire pressure, running your a/c, stuck in traffic (this is where you are getting 0 mpg), the list goes on & on.....

There are ways to determine if there is a problem but what you are talking about is long gone. Run a few tanks to double check your #s and make sure EVERYTHING is up to par, tires, alignment, filters, the whole list and be aware of things you are doing that can kill your mpg. If after a few tanks you think it's still off you are going to have to take it in to be checked... The datastream is going to have to be looked at to see if it is in fact in fuel control. If not then the trims & other data can be looked to determine where the problem lies....

You don't have the equipment or knowledge to trace this one down....

One other suggestion I'll make is maybe get the fuel system serviced before you start checking your mpg. Just make sure it's a place that runs cleaner thru the fuel rail to clean the injectors & just doesn't hook a little bottle up to a vacuum hose. That way is good to clean the intake but you also need to run clean thru the rail to clean the injectors...


Discretesignals
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Aug 7, 2011, 3:39 PM

Post #8 of 19 (5140 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Believe it or not you can actually check the base timing on this thing and dynamic timing at idle. You can check it, but there aren't any adjustments. You can also watch the timing advance PID on the scan tool while driving to see if the computer retards it. Even if it did, you would have to determine the cause. You shouldn't have to worry about the runaway problem, which was never duplicated by the engineers, because your throttle valve is cable operated.



1. REMOVE V-BANK COVER
a. Using a 5 mm hexagon wrench, remove the 3 cap nuts.
b. Loosen the V-bank cover fastener counterclockwise.
c. Remove the V-bank cover.

2. WARM UP ENGINE Allow the engine to warm up to normal operating temperature.

3. CONNECT TOYOTA HANDHELD TESTER OR OBDII SCAN TOOL

a. Connect the TOYOTA hand-held tester or OBDII scan tool to the DLC3.
b. Please refer to the TOYOTA hand-held tester or OBDII scan tool operator's manual for further details.

4. CONNECT TIMING LIGHT TO ENGINE
Connect the clip of a timing light to the lead wire as shown.

5. CHECK IDLE SPEED
a. Race the engine speed at 2,500 rpm for approximately 90 seconds.
b. Check the idle speed. Idle speed: 700 ± 50 rpm

6. INSPECT IGNITION TIMING
a. Using SST, connect terminals TC and E1 of the DLC1. SST 09843-18020
b. Using a timing light, check the ignition timing. Ignition timing: 8 - 12° BTDC @ Idle (Transmission in neutral position)
c. Remove the SST from the DLC1. SST 0984-18020

1. FURTHER CHECK IGNITION TIMING Ignition timing: 7 - 24° BTDC @ Idle (Transmission in neutral position) HINT: The timing mark moves in a range between 7° and 24°.

2. DISCONNECT TIMING LIGHT FROM ENGINE

3. DISCONNECT TOYOTA HAND-HELD TESTER OR OBDII SCAN TOOL

4. REINSTALL V-BANK COVER
a. Using a 5 mm hexagon wrench, install the V-bank cover with the 3 cap nuts.
b. Press down the V-bank cover fastener.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Aug 7, 2011, 3:49 PM)


Alex Ethridge
User

Aug 7, 2011, 4:11 PM

Post #9 of 19 (5135 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

"PS, The was never any cover up or computer failure proven with Toyota vehicles so again you have no clue about what you are talking about."

Yes, and cigarettes didn't cause cancer, either. When greed is involved, big money will lie, steal and even kill (cigarettes). Pardon me if I don't want to take BigMoney's word on it.

One of my own 2001 Siennas has had a mild acceleration problem. (Yes, I know, it wasn't in the recall; but, the problem is there occasionally anyway.) It pops up without warning. It's not severe; but, I can be sitting at a traffic stop and suddenly it just wants to take off. If I lift my foot from the brake it will slowly accelerate to a speed of over 60 MPH. It may take nearly a half mile to get to that speed; but, it happens without any help from me. This behavior will persist for a week or so and then just quit and be back to normal. And it's not my foot or my floor mats. It's happened about five times since I've owned the car, lasting about a week at a time.

Technology hasn't left me in the dust entirely. I am the owner/operator/technician of a computer and small network service company since 1995.

In the end, I may have to give up on this; but, I haven't decided that yet. Right now, I'm in the first stage, learning all I can about it.

This much I have reasoned out on my own: There may be a lot to do with ignition timing that is hard coded into the nuts, bolts and steel components; but, in the final stage it is not even the computer hardware that determines when it fires; it is the firmware in that computer that determines ignition timing. I may even have to replace the computer just to change the timing and that would be cheaper than $10,000+ worth of wasted gasoline over the next 200,000+ miles.

Sidom:

I've eliminated the factors you mentioned. All tires on both vehicles are at 34 pounds. The 01 Sienna is actually loaded more heavily with shelves, bins and computer parts estimated at about 350+ pounds. The 03 is empty; even the third-row seats are removed at present in anticipation of installing the same equipment as in the 01. Both cars are running radial tires. Birmingham isn't so big that being stuck in traffic happens much. The last time that happened for me was about four months ago. The fuel pump and fuel filter have been replaced and the fuel tank and lines flushed and resealed. If there is a fuel leak, I can't find it visually or smell it. Wipes from both tail pipes are very light grayish-brown.

I will take it to the Toyota mechanic; but, I want to verify the timing for myself before I do (if I can figure out how to get my induction timing light on that thing).

A "few miles per gallon" (five to be exact) is $10,000+ over the life of the car (200,000 miles +); that is not insignificant.

If there is no solution to this low-mileage problem, I will come out better selling it.


Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 4:17 PM

Post #10 of 19 (5131 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  


Quote
I may even have to replace the computer just to change the timing and that would be cheaper than $10,000+ worth of wasted gasoline over the next 200,000+ miles.


That would do absolutely nothing for you since the computer is only the hardware and it would still have be programmed with the same software that it is now.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Alex Ethridge
User

Aug 7, 2011, 4:27 PM

Post #11 of 19 (5120 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Replacing the engine computer would be done on the theory that the existing engine computer might be defective. Those computers have been known to fail and when they fail, it isn't always a sudden, total failure. Sometimes, it fails in the form of just quirky behavior -- like maybe even the timing being off or unexplained loss of power. I pulled one out of a ten-year-old car a few years ago and replaced all the capacitors on its little board. They were swollen and corroded. Luckily, we got to it before the corrosion damaged the board.

If the engine computers are the same, I might try swapping the one out from the 01 just to see what happens -- if I can find time before I sell it.


Alex Ethridge
User

Aug 7, 2011, 4:28 PM

Post #12 of 19 (5116 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Thanks, Discretesignals. You've made me very happy with that info.



Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 4:29 PM

Post #13 of 19 (5115 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Like I said. By the time you're done tinkering, you will likely have a real problem that you didn't have before. Don't say i didn't warn you.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Aug 7, 2011, 4:31 PM

Post #14 of 19 (5112 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Regardless if you believe the timing is causing your fuel mileage to decay and loss of power, you need to monitor the timing to see what is actually going on.

Just like your work with computers, you have to duplicate and determine the cause by running tests. You don't replace the whole motherboard because a computer doesn't turn on and you feel the motherboard is the problem. You have to do some troubleshooting first to determine the cause or else your wasting the customer's money and your time.

You'll have to monitor the ignition timing and advance as the computer makes it's adjustments. You can even go as far as to scope the system to visually see the computer commanding coil operation and map out the timing at different load and rpm ranges.

I really wouldn't blame your condition solely on the ignition timing model in the software of the computer if you have a sudden loss of ignition advance intermittently.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


Hammer Time
Ultimate Carjunky / Moderator
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Aug 7, 2011, 4:34 PM

Post #15 of 19 (5107 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

You're wasting your typing DS. He has no comprehension of how the system works.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Alex Ethridge
User

Aug 7, 2011, 5:04 PM

Post #16 of 19 (5100 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

"You're wasting your typing DS. He has no comprehension of how the system works."

A bit insulting, I believe. I have a full comprehension of this much: The timing isn't intended to be adjustable. I can check the timing with the instructions DS gave me. I can proceed from there depending on the results of the timing check.

One step at a time in the diagnostic process of elimination.

I'll get back with my results when I've had time to do the diagnostic work. It'll probably be a week or more since I don't have the code checker and I intend to order on-line to save about a hundred dollars.


Sidom
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Sidom profile image

Aug 7, 2011, 7:58 PM

Post #17 of 19 (5083 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

What you can do if you haven't already which can make a difference on the MPG is to get the injectors cleaned & cleaned the correct way...... Make sure it's thru the rail. Alot of places advertise injector cleaning but it's just an intake bottle...

Also get a can a MAF sensor cleaner & clean the mass air flow (make sure to do the sensing wire & not the temp sensor, if in doubt, clean them both). If the sensor gets slightly skewed, it can affect your mileage as well as performance....

Usually your mileage will drop before you notice any performance problems (if it's a slow progression failure) and then eventually you'll notice it in the way it runs.....

Make sure to use the correct cleaner.....


Alex Ethridge
User

Aug 7, 2011, 9:03 PM

Post #18 of 19 (5076 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

Yes, I see why cleaner run through the intake wouldn't have much effect on the injectors. I saw a video on how scottykilmer.com did it through the rail. Cleaning the injectors is something I will do because I don't want to leave any stone unturned; but, seeing the exhaust residue is currently light gray-brown, I don't have much faith that will make a difference.

To this point, all I've done with these all-electronic, computer-controlled cars is drive them as they gave me no trouble and good mileage. Unfortunately, the fun is over and it's time to learn about maintenance and troubleshooting.


Alex Ethridge
User

Nov 1, 2011, 8:07 PM

Post #19 of 19 (4935 views)
  post locked   Re: How to set ignition timing on 2003 Toyota Sienna?  

I know it's been a long time since I started this thread; but, I finally pushed forward and checked the timing with a light that has a built-in tach. The best I can tell from the instructions I got, the timing is off almost 2 degrees at idle and almost 4 degrees at higher RPM. Since I have very little experience at this, I took the car to the friend from whom I borrowed the timing light to get a second opinion. He's been a mechanic all his life, forty years or so.

He got about the same result I did.

I guess the next step is to find out what can be done about this. The mileage is still enough below what it was on my two 01 Siennas to make a $10,000 difference in fuel cost over the life of the vehicle (assuming fuel cost at about $4 a gallon).






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