Glad i could be of assistance!

If it's throwing a TPS code, then most likely the potentiometer contacts on the inside have started to go south and there is not much you can do to save it. Cleaning them has a tendancy to degrade the internal components even further, and all the Toyota manuals specify NOT to clean it for that same reason. Its a little pricey (over $100 OEM) but they are pretty simple to install with a multimeter and it will help significantly.

As far as the timing belt being off a notch, pull off the drivers side spark plug cover and rotate the crankshaft to TDC. there should he some sort of visible indicator on both the cam pulley and the belt itself that should line up, telling where the belt should be

 

you can remove the cam pulley covers and plugs in about 15 minutes and then turn the engine clockwise using the crank pulley bolt and verify the timing belt has not jumped using the marks, but if the timing belt has cracks it is way over due to be done anyway.

 

I cleaned my tps 2 years ago with contact cleaner (due to a cel) and have not had a problem since

 

Put in a brand new TPS, the symptoms persist. Clean out the error codes and ran the engine again. Got the same codes. I guess what remains is the jumped timing belt. Changing the timing belt will be the next project. For discussion, I wonder what is the effect of jumped timing belt. I guess messing up the timing is one thing. But the engine idle pretty smoothly.

 

The timing belt needs to be changed if it is starting to crack or rot. I had similar issues and codes. I changed tb, ect, waterpump and plug wires. Runs like a champ.

 

Started the timing belt job. Still at the disassembling stage. Could some one tell me how to post images? I click the "insert image" button above and it ask for a http:// address. My images are in the computer directories (like desktop). How do I specify the address of the images? A few problems I can see now. They are listed below.

- The timing belt did jump! I lined up the mark at the crank and the marks on the distributor wheel (driven by Timing belt) are two teeth ahead of marks on the back plate. Will post pictures later.

- Both of the electrical connectors for the cam position sensor are damaged. When I press on the release tab, they broke. I suppose after 22 years of being near the engine heat, they become brittle. How do people deal with the situation?

- I suppose cowboy would not oppose using FIPG for the water pump! I am not familiar with FIPG, but I am thinking I would throw away the gasket came with the pump!

- Is this a good time to work on the power steering pump such as the ACV valve? Neofate's guide was very helpful!

- I will be replacing the crank and cam seals. Any tricks in doing these jobs?

 

I upload the images to a free image hosting service such as imgur.com

You definitely need the real paper Lexus factory service manual for your LS400 to do a timing belt properly, if you cannot afford to get one used off ebay, then sign up for a 2 day pass at Toyota's information service for only $15 and download the appropriate service manual pages

any good Toyota-heavy junkyard, where you pull your own parts, this connector was used on a lot of Toyotas from the 90's, start with the trucks/4runners and go from there. Expect to spend about $2 for each one and bring some tools to get them and pull several to find some in good shape, then once home, just wire up the pigtail you pulled into the main harness and remember to solder and heatshrink your connections!

a water pump is the place for FIPG, not a transmission!

The power steering leak would be a high priority for me if it is leaking on to the alternator because it will kill the alternator (you will have fluid spots in your driveway), if all the leak is into the vacuum system, then it would be a much lower priority for me.

No real tricks, just good lighting and attention to what you are doing.

PS - I wouldn't even start this job without a good quality torque wrench and also a plan for breaking the Jesus bolt (crank pulley) a high quality 1/2 inch impact is the easiest, but a long breaker bar and the starter is the old standard redneck method

this video, though not your year, should help a lot!!

 

This picture shows how bad a shape the timing belt is. The car is a 1991 LS400 with 135K miles. I think I am doing its first timing belt change.







The next picture shows the jumped timing belt. The crank mark is lined up with 0, and the picture shows the distributor wheel mark relative to the white mark on the back plate.







Now the challenging question:



How do I mark the old belt for transferring to the new belt? I will move the distributor wheel mark back (for both distributors) to be in line with the mark on the back plate after the timing belt is removed.

 

What happened to the engine! Mystery solved!

While doing the timing belt job, I noticed broken red plastic pieces all over the place. See the picture below:




After opened up the right distributor cape, I was shock to see it empty with a pile of broken red plastic debris:



Then I realized the rotor has shattered inside and spread broken plastic pieces all over the place. The cap look terrible with the rotor tip stuck at the side






The left side distributor rotor was also broken,



It's amazing the engine runs (idle smoothly) with this kind of condition.


- I wonder if the shattered rotor caused the timing belt jump or the timing belt jump caused the rotor to shatter?

- The rotor shows DENSO. Is this original part? I will need to buy both distributor cpas and rotors, any suggestion of place and brand to buy?

- The inside wall of the right distributor position sensor was scratched. Is it still good?


Appreciate all previous comments especially Cowboy. Thanks!

 

yuck! I've never seen anything like that!

OEM CAN be cheaper when ordering from the right place.

I buy all my OEM parts from Lexus of Pembroke Pines. Cheapest price ive found. google "trademotion lexus pembroke"

Site is very easy to use. Dennis and Troy are very nice and helpful. shipping runs about 10% of purchase price.

caps run about $16 each IIRC

 

Cheaper than Sewell with our discount?

 

sewell is cheaper, but not by much..... just checked.