Salim,

I believe the GS300 is non-interference and the GS400 is interference.

jonny

 

Sure i'll do it tonight and post them.

 

Read up on this:

http://www.motoringtv.com/quakerstate/cranksensors.php

In the image below you can see my crankshaft sensor. Notice how clean it is, lets just say it did not clean on it's own or was cleaned with water

I'll be picking a new one up tonight just incase if this the issue.

 

That should be fine. Theres not really any dirt to get inside and onto that. You did put your tabbed metal ring back on too, right????


Actually stupid question... Are you trying to start the car before reassembling it? There is a brass colored ring that should be on the crank that if you don't put it on the car will not spark.

 

No mine was pretty filthy. Although it has a cover mine was all oiled up, you couldn't even see the metal part. It was all covered with oil/dirt.

No i have not yet started the car or put everything back. It has the brass ring and have not put that on yet. So tomorrow i'll put everything back and try starting it. But as of last night just put the belt back on and that is about it.

I guess this would be another part i can swap with my brothers car and see if it is still working. I just read up on the site and the symptoms matched what i was running into.

Let see tomrrow. Thnx...

 

Well, after putting everything back together. Manually cranking the engine, it was moving freely just fine. Tried starting the car and made a backfiring sound so stopped cranking. Manually spun the engine again and it’s moving smoothly. So now I’m done I guess. Don’t feel like taking another attempt to start it.

So what is next; mostly likely will have to tow it into the Lexus dealer.

Thanks for everyone help!

 

Is there an option to see "|" vs "T" mark on your friends car? Also if you are willing you can poke through the sparl plug hole to confimr "TDC" on "|" vs "T".


Back fire atleast confirms presense of spark although not at the right time.

Learning for the rest is "mark the reference points with paint or markers before removing the belt."


Salim

 

Today prety much compared everything to my younger brothers car.
- "l" versus the "T marks
- TDC piston on mine versus his
- removed the valve cover and compared the position of the valves with his
- within the valve cover compared the gears postion when timing is set. The one dot matched exactly as mine.

So all items listed above matched exactly as what i have on my car with his GS400.

I have no idea what i'm missing here. Will find out when i take the car tomorrow to the dealership.

 

Did you happen to unseat any connectors? Say the altenator? or maybe with all the movement in the engine bay one of them became loose, check them all before towing to the dealer. I have a GS300 so obviously quite different in the engine bay but you never know.

Dx3--GS300 2JZ engine IS also an interference engine. I bought one that spit it's timing belt in an accident and it had two broke valves and four bent ones...D

 

Yeah we were working around the power steering unit when the alternator fews blew. Alternator right below the power steering unit. So yup yesterday we traced the wires and made sure nothing pulled out or got cut. Alternator is easy to pull out. So i can do that and double check.

 

Just an update, the car is at the dealer... Tech checked the timing belt and says that is correct. Lets hope first time when my timing was off didn't wreck anything since the car never started. He did the diagnostic and came back with the Air flow meter/sensor not working. They don't have one in stock so they are getting one tomorrow morning. I don't know, i called my brother he disconnected his air flow sensor on his Gs400 and his started up just fine, with check engine light and other lights but at least his started.

So i have a bad feeling about this now. Let see what they say tomorrow. I hope they just don't start replacing parts left and right.

Image of the car being taken away

 

Pardesi,
I am so sorry that you are going through all this trouble. Working on the timing is quite easy if you have an idea of what you are doing, but it can be a nightmare if you get something wrong.

The timing belt instructions DEMAND that the engine be rotated in order to get the timing done right.

For reference sakes, the "center" pulley as you call it is the CRANKSHAFT. The upper pulleys are the CAMS. Each CAM pulley is responsible for 2 cams. One of those cams is an INTAKE cam, and the other is the EXHAUST CAM for that bank of 4 cylinders Each cam spins and opens and closes 8 valves. 8 X 4= 32 valves. That means that each cylinder has 4 valves....2 intake and 2 exhaust. This is very complex, and timing is critical. Turning the engine over by HAND slowly does NOT bend the valves. Bendng the valves requires engine speed, such as running at 1000 to 2000 rpm or higher in the wrong sequence. If the engine idles in the wrong sequence it means that it is CLOSE enough to run, but still OFF enough to bend something. The fact that your car BACKFIRED indicated that you were OFF enough to prevent the engine from even starting. For that you should be lucky.

The CRANK has to be turned around from "0 degrees to 0 degrees TWICE to make the CAMS rotate ONCE from 0 degrees to 0 degrees. The cams rotate at HALF the crankshaft speed.

You also have 2 SETS of marks...the marks on TOP, and the "T" marks just off center to the right behind each CAM pulley on the case. Look closely and you will see the small "T" marks You have a HYDRAULIC TENSIONER underneath that makes the belt tight. You SHOULD have rotated the CRANK 50 degrees PAST the TDC mark BEFORE taking off the tensioner and subsequently the belt. There is a small WHITE DOT on the front case. The timing mark on the harmonic balancer should have been aligned on this white DOT, and not the "0" position. THIS IS CRITICAL. The white dot has to align up before removing the front case and exposing the belt. When installing the new belt, the cams line up on the "T" marks, and the "C" below goes on the crank pulley lined up as well. A new replacement belt from Lexus has all 3 marks on the belt surface. They get worn off as time goes by. The cam pulleys have a small "dot" on the front face of the tooth where the painted line on the new timing belt goes.Don't expect to see the marks on the belt itself line up with the TIMING marks after turning the engine over the first time...remember the cams and crank turn at different speeds when running correctly so watch the marks on the CAM and the CRANK. Every other time the CRANK tuens and aligns with TDC on the harmonic balancer, the cams should line up on the marks straight up, and turning it all 50 degrees more should put the cam marks on the small "T".

I am not sure how the mechanic can say that the engine is in TIME if it backfired. The fact that the car BACKFIRED is a sign that the coils are firing, so go on from that point.

I think you learned a valuable lesson about disconnecting the battery when doing mechanical work under the hood, so don't dwell on that for now. It is done, so move on. A BACKFIRE usually indicates firing out of proper time. In older cars WITH a distributor it is possible to put the wrong wire on the wrong plug, and when the coil fires it goes to the wrong cylinder.

Since this car does NOT have a distributor, AND each cylinder has its' OWN coil, the ONLY way the car can be out of time is the fact that your crankshaft and cams are not in proper relationship with each other. Add this fact to the other fact that the car was RUNNING before you pulled off the belt, and it should be obvious that something is out of time.

As you stated earlier, the mass air flow meter CANNOT stop the engine from starting. It WILL run, but you will have a check engine light if the air flow meter is disconnected.

I have a few other comments...

1. The fact that you had "oil and dirt" all over the teeth on the "crank" pulley indicates that you possibly have a crank seal leaking. This should be changed BEFORE putting it back together. If this oil seal continues to leak you will have a bunch of problems in the future. Both of my engines were spotless in this area, indicating no leakage at the seals. In fact on my first engine, I did not change the seals since I use AMSOIL synthetic oil, and everything was tight with only 90,000 miles on the engine. Any evidence of leakage indicates a part that should be changed. You should be looking at all the seals including the camshafts and the valve cover gaskets. If you don't change the crank seal:

a. Oil will get all over the crank sensor, which will stop the coils from firing. You'll get a code for a bad crank sensor, but it is really good, but just covered with oil. That metal piece on the crankshaft behind the belt gear passes over that crank sensor and makes the coils fire. Clean it up and put it back on.

b. This same engine oil will get all over the teeth of the belt, and this WILL eventually cause the belt to slip around the cams, and this may slip and put the engine back out of time. PLUS this same belt turns the water pump, and a slipping belt can cause overheating, because the pump is not turning properly. If this car has not had periodic oil changes, or inferior oil was used, the seals will most likely be leaking. Changing the seals behind the cams is tough but can be done.

I don't suggest that you change JUST THE BELT when it is obvious that you need other things. Do the water pump, the seals, thermostat, the special "O" rings around water pump and finally the Tensioner. It makes good sense, because a leak in here anywhere requires going back into the engine AGAIN.

I have done 2 Lexus GS400 timing belts so far with no problems, but I changed seals and the water pump each time to prevent future problems. The last belt I did last year at 90,275 miles, and now I have 132,000 miles on this engine, so it was done right.

Lining up the timing belt is one thing, but THE CAMS MOVE WHEN TENSIONER tightens up. After lining up the belt, the tensioner is the last step to be done to tighten up the belt. A small pin holds the tensioner down to allow belt installation. Once the belt is in place, the pin is pulled, and the tensioner moves up and tightens the belt. That belt will be TIGHT!! The tensioner keeps the belt tight enough to spin the cams and the water pump. I think that the tensioner is what threw your adjustments off. When my marks were off I had to remove the new tensioner, use a PRESS to push the piston back down, and reinsert the throwaway pin. I then reinstalled the tensioner in the timing case and realigned the belt until I got it right.

There are 2 bearings that should also be replaced....the stationary bearing on the right, and the adjusting bearing on the left just above the tensioner.

After all of this is done, THEN the CRANK has to be rotated 720 degrees, (or twice around) to ensure the CAMS above rotate ONE COMPLETE turn (360 degrees). If you did not so all of this, chances are you are out of time.

The book says that after one complete revolution of the cams, ALL marks should line up (CRANK NOW AT "0" and the two cams on the straight up marks. THOSE STRAIGHT UP MARKS are the actual timing marks when the crankshaft is at TDC. If it is wrong, the book says that the tensioner has to be loosened, and the belt removed while the cams are repositioned.

This indicates that the valves cannot be bent JUST BY TURNING THE ENGINE OVER BY HAND. I had to retime mine TWICE to get it right, but I did NOT start the engine until I did 2 crank revolutions and all the marks lined up.

Then I connected the necessary wiring and quickly started the engine for a few seconds. If it won't run with it all apart, it won't run when it is all together. I knoew I would have a "check engine light" because I did not have the mass air flow meter connected. I have a scan tool to correct this once the car is fully assembled.

I am sorry this took so long, but I think you will find that your engine is out of time. I am convinced that changing parts will not fix this, especially since all of your parts work on your friends' car.

Again, I am NOT condemning you, so please don't take offense. The lining of marks is CRITICAL to make this engine run right. Lexus charges a lot to do this job, but they usually don't cut corners, and they change all the parts they need to in order for everything to last another 90,000 miles minimum.

I don't WANT to go back inside my engine until it is time for another belt. I used to whine about changuing a perfectly good water pump at 90,000 miles, but I realized that changing this pump is a lot of work, and if it leaks, the belt could slip and throw everything out of whack.

Good luck man, and I hope you get your car running again very soon!

 

GSEREP1 .... i don't know what to quote, you presented with so much good information. Thanks!

Yup my first mistake was not disconnecting the battery, therefore i'm dealing with electronic issue versus timing issue. I totally understand the timing setting now and believe that is how mine is setup since i know i never rotated any of the cams alone. Only thing happened with mine was the L cam moved and i moved it back. I made sure i didn't make a full circle. My current timing is set at the two T marks. Crankshaft pulley is approx. 50°clockwise, and put the timing mark of the crankshaft pulley in line with the centers of the crankshaft pulley bolt and the No.2 timing belt idler pulley bolt (see below image).

Tech confirmed today that my timing is set correctly but i'll mention it to him again. For now I am happy to hear your comments that i am lucky since the engine never started the first time when my timing was off, so I might have not wrecked the valves.

As for replacing the water pump, mine does have a new one in it with the seals. I didn't change the two bearing or the tensioner. Once i get it going i'll have to further inspect that oil. Although it was dried up oil not fresh.

Anyways, thanks for your input. I don’t know if i mentioned this but yeah we also did another GS400 about a month ago so that went smoothly. I just hope they get the car running soon.

 

Forgot to attach the image...

 

GREAT,
I am glad to hear that things went well. I just make the comment that I have never heard a fuel injected engine backfire if it was in time. Old carburetored cars would backfire from time to time if the carb adjustment was off a bit.

I also say that if you have a backfire, the coils are definitely working. You obviously replaced that 120 amp alternator fuse. That fuse absorbed the "dead short" to ground you caused with your wrench around that alternator. Since the key was not "on" at the time, I don't think you did any damage to the electrical circuits. I would be very very suprised.

Did anyone scan the engine and see which cylinders are misfiring (if any)? How about any other codes?

Good luck! Please keep in touch...I want to hear what you did to get this beast working again.