96 Ls400 Bad Gas Mileage! Tried Everything

[yotoy82]

I'd say over a 1000 miles I'm averaging about 14 mpg in the city at best. All winter was getting about 9 mpg in the city, and 11 mpg in the city during summer right now. If I go on the highway I might get 20 mpg max. Only on one lucky day I was able to squeeze 25 out and that was a miracle, but other than that nope.

But my father has a 95 LS400 which is almost identical to my 96 LS400 and they get 19 in the city pretty constantly and about 26 on the highway no problem. They have never gotten 11 mpg like I have gotten, and I am consistently getting 11 mpg unless I get on the highway to make a trip, than my mixed mpg is about 16-17.

I would LOVE to get 16-17 mpg in the city! If I fill my gas tank up fully and just start from scratch on a 2 hour trip averaging 55 mph only THEN I'll get 25 mpg. Otherwise regular interstate driving I'm getting 20 mpg =( Something is wrong for sure because makes no sense another LS400 we have that is actually much less maintained gets twice the miles per gallon I get.

You seem to still be talking in generalities rather that specifics. Keep detailed track of your fuel mileage over a number of tank fulls and then report back. Trying to determine what gas mileage you are getting in city driving vs. what you are getting in highway driving is very difficult.

If your father consistently gets 26 mpg in highway driving in his 95 4-speed transmission LS400, I'd call it a miracle. The very rare times I've exceeded 26 mph in my 2000 5-speed LS400 have been on long (e.g. 700+ mile football weekend) trips mostly on cruise control where I did viturally no low speed driving other than to pull off the interstate, fill up the tank, and continue on down the interstate at speeds within the speed limit, in low/no wind conditions, in a lightly loaded car carrying only two people and a couple of small suitcases. Even a little low speed stop and go driving or a head wind makes my overall average fuel mileage plummet.

Disregard your iPhone app, buy a small booklet and record every fuel purchase, date and and odometer reading for the next 1,000 miles. I've done this for about 700,000 miles of driving and can attest that doing this eliminates guessing.

The iPhone app is the same thing as a booklet, it records every fuel purchase, date, odometer reading. I enter the odometer reading, indicate that I filled up, how many gallons the fill took, and I get my mpg. Its literally the same thing as doing it by hand. I can honestly say that I am getting 11 mpg and this has been going on for 9 months now.

I can honestly say that highway mileage is good, 20-23 is reasonable. But 11 mpg city just is horrible no matter how you put it, I'm literally not exaggerating, or doing anything wrong in recording or driving habits. Hell, our old 87 420sel with 290,000 miles on it, which isnt maintained at all is getting 14-15 mpg in the city!

I've come to the conclusion it could be the thermostat or some air leak though. I don't care if its normal mileage I'm getting but I think the extra fuel is damaging my catalytic converters slowly and oxygen sensors and I had to replace those because they both went bad at the same time 2000 miles ago, so worried about the unburnt fuel. I thought changing the oxygen sensors and spark plugs would prevent them from going bad again but the mileage still hasnt improved. If I drive on the interstate anywhere I can get 220 miles until reaching half a tank, and in pure city driving I get 100 miles at half a tank.

And I get 9 mpg in the winter, and 11 mpg in the summer with the ac on.. *sigh*!

[1990LS400]

The iPhone app is the same thing as a booklet, it records every fuel purchase, date, odometer reading.

According to your phone app, you filled your tank 6 times in 424 miles and 16 days. Why are you doing that? Try calculating fuel mileage over full tanks of fuel. Fill up and don't buy gas again until your gauge falls below 1/4 tank. There is too much variablility when a tank is topped up every 50 to 75 miles to accurately calcuate fuel mileage. Even then, don't calculate you mileage by individual tank fulls. Calculate your mileage over four or five tank fulls.

Contrary to popular wisdom, I suggest occasionally running your tank down until the low fuel light comes on. Some say that can cause problems from debris clogging fuel filters but I've been doing that for decades with never a problem. In some of the European cars, I've often let the main tank go dry and let the engine start missfiring before activating the fuel reserve switch. IMO, doing that gets rid of the crud and water and keeps it from building up and floating on top of the gas in the tank.

[yotoy82]

The iPhone app is the same thing as a booklet, it records every fuel purchase, date, odometer reading.

According to your phone app, you filled your tank 6 times in 424 miles and 16 days. Why are you doing that? Try calculating fuel mileage over full tanks of fuel. Fill up and don't buy gas again until your gauge falls below 1/4 tank. There is too much variablility when a tank is topped up every 50 to 75 miles to accurately calcuate fuel mileage. Even then, don't calculate you mileage by individual tank fulls. Calculate your mileage over four or five tank fulls.

Contrary to popular wisdom, I suggest occasionally running your tank down until the low fuel light comes on. Some say that can cause problems from debris clogging fuel filters but I've been doing that for decades with never a problem. In some of the European cars, I've often let the main tank go dry and let the engine start missfiring before activating the fuel reserve switch. IMO, doing that gets rid of the crud and water and keeps it from building up and floating on top of the gas in the tank.

Yah, I filled it often. I usually fill it around the halfway mark, don't know why. Will ride it until its all the way empty and let you know how it shows then.

[yotoy82]

I'm doomed. Literally at the halfway mark on the fuel tank and just 100 miles driving for this tank (100% city)! If I drive on the highway It will be like 220 at the halfway mark though, which is ok. Say what you want too, but that is completely wrong. I almost thought its quite possible my tripometer was inaccurate, or my fuel gauge is off, but when I go to fill it up surely enough it has plenty of space. At this point in time I'm thinking I might have a fuel like, but no smell or anything visible. City mileage at 11mpg is just disgusting =(

No one can tell me my 96 LS400 is as bad as these guys http://autos.yahoo.com/news/greediest-guzzlers.html

The elusive search for a cure continues

[yotoy82]

Half a tank... 104 miles driven. I know some may argue that half a tank doesn't mean exactly HALF a tank, but I bet everyone shows at least 150 minimum when their tank is showing half full, I know its not an "exact science" indicator. But after driving for 15 years I can honestly say after a while you get to know how cars and the fuel meter works, and I can honestly say I've never driven any car with the gas tank half empty at a hundred miles.

And yes, I fill up exactly the same each time at the same gas station, I let it stop by itself when it gets full. (and yes I've tried other gas stations, same results).

And when I go to fill up this half tank, it will take me around 10 gallons to get full again.

I've noticed even though its a 100 degrees F today, that is as hot as my engine temperature shows, is that normal, because I've seen some LS400's show a "half" a notch higher than that.

[SRK]

I'm just putting this out there, but you have checked that the trans is shifting up through four gears, and you are cruising at a low rpm?

[jac430]

I've noticed even though its a 100 degrees F today, that is as hot as my engine temperature shows, is that normal, because I've seen some LS400's show a "half" a notch higher than that.

My LS430 gives exactly the same temperature indication. This is absolutely perfect!

Jac

[yotoy82]

I'm just putting this out there, but you have checked that the trans is shifting up through four gears, and you are cruising at a low rpm?

haha yah, its an idea but its shifting fine. On the interstate around 65 mph I'm around 2000 rpm roughly.

I've noticed even though its a 100 degrees F today, that is as hot as my engine temperature shows, is that normal, because I've seen some LS400's show a "half" a notch higher than that.

My LS430 gives exactly the same temperature indication. This is absolutely perfect!

Jac

Thats good to know, thanks for the reply! I guess its down to just a vacume leak somewhere now

[curiousB]

Too many generalities and not enough hard data to conclude anything.

You need to do a full tank MPG calculation on normal city driving (not parked and idling for long periods). Regular day to day driving.

You need to confirm if you have dragging brakes or not. Comments like it seems to be fine and it coasts forever are simple generalizations. Outside ambient temperature is also irrelevant. The brakes will be 300-400+ degrees if they are dragging. The difference between 65 and 99 degrees ambient is nothing compared to 400 degrees.

The vacuum leak theory would show up in your fuel trims. The car would have long term fuel trim elevated to compensate for the leaning of the engine causes by a vacuum leak. You said trims were fine.

[Banshee365]

CuriousB is right on track from the first post on I think. The '96 has a fairly high failure rate for ECM's, especially at that mileage. I've had to put one in mine because the reference voltage in the ECT circuit in the ECM was way off causing the car to think it was never warming up. It would run great cold at startup then slowly get worse. The ECM kept the mixture very rich and my car was so bad that it would stall and not start unless it was cold.

ECM's seem to be wear items on some of these LS's and routinely start showing symptoms at miles over 200k. It's whether you realize it or not in most cases. In a perfect world you would have a friend with another '96 where you could swap ECM's and drive a tank through it and note the difference. If you come across a good deal of a '96 ECM I would snatch it up and keep it for things like this. If you plan on keeping the car for a while that is one part I would be on the look out for. Make sure it has lower miles and is guaranteed if possible.

[yotoy82]

CuriousB is right on track from the first post on I think. The '96 has a fairly high failure rate for ECM's, especially at that mileage. I've had to put one in mine because the reference voltage in the ECT circuit in the ECM was way off causing the car to think it was never warming up. It would run great cold at startup then slowly get worse. The ECM kept the mixture very rich and my car was so bad that it would stall and not start unless it was cold.

ECM's seem to be wear items on some of these LS's and routinely start showing symptoms at miles over 200k. It's whether you realize it or not in most cases. In a perfect world you would have a friend with another '96 where you could swap ECM's and drive a tank through it and note the difference. If you come across a good deal of a '96 ECM I would snatch it up and keep it for things like this. If you plan on keeping the car for a while that is one part I would be on the look out for. Make sure it has lower miles and is guaranteed if possible.

You make the best point on here. That's the one thing I always think about and fear is most likely the culprit here! But its kinda hard to diagnose a bad ECM because technically it isn't "bad" but not working "properly". Are they easy to change? I guess it wouldn't hurt to get one if can find a good deal on one somewhere. Because sometimes outta the blue, the car runs SUPER smooth and quiet and gets great gas mileage, and then it goes back to being its bad self again as if its a loose connection or wire somewhere.

I've spent a ton on this car already and plan to drive it another 5-7 years at least, I don't see what other item could be causing the problem except the ECM as well. Otherwise its a useless chase and people keep saying I must be driving incorrectly or saying thats just how the mileage is, makes me wanna say "here take the car and drive it yourself for two weeks and tell me how you feel at the end!".

But just curious, if the ECU/ECM is bad, wouldn't it show on the fuel trims?

[Banshee365]

You make the best point on here. That's the one thing I always think about and fear is most likely the culprit here! But its kinda hard to diagnose a bad ECM because technically it isn't "bad" but not working "properly". Are they easy to change? I guess it wouldn't hurt to get one if can find a good deal on one somewhere. Because sometimes outta the blue, the car runs SUPER smooth and quiet and gets great gas mileage, and then it goes back to being its bad self again as if its a loose connection or wire somewhere.

I've spent a ton on this car already and plan to drive it another 5-7 years at least, I don't see what other item could be causing the problem except the ECM as well. Otherwise its a useless chase and people keep saying I must be driving incorrectly or saying thats just how the mileage is, makes me wanna say "here take the car and drive it yourself for two weeks and tell me how you feel at the end!".

But just curious, if the ECU/ECM is bad, wouldn't it show on the fuel trims?

Replacing the ECM is usually the last action in the diagnosis in anything the ECM controls when it comes to diagnosing through the factory books. Diagnosing the ECM is tough but is done by somewhat of a process of elimination. At first I had a slightly rough running car. I replaced the plugs, wires, caps and rotors with OEM parts. The car seemed to run slightly better but still somewhat rough and I just thought "Whatever..." Over a year later the car starts really running like crap and throwing a CEL for the engine coolant temp circuit malfunction. I replaced the engine coolant temp sensor for the ECM to really no avail, it still ran terrible. I have a Lexus tech buddy that works at a Toyota dealer and I was at whits end with the car. The next thing I thought was O2 sensors as they are original on 230k miles. We hooked the car up to a scanner and the O2 sensors appeared to either be going bad or the cats getting very very weak as the line should have been mostly flat and its was jumping a little at idle. Then he pointed to 2 mid 90's Lexus's sitting in the parking lot waiting on ECM's and we agreed that they seem to have issues with age and miles. We removed the glovebox and checked the reference voltage, which should be around 5V I think. It was over 8V.

The ECM measures temperature by resistance that comes from the temp sensor on the engine. To get a reading for the ECM it needs a reference voltage on each temp. circuit while the logarithm is calibrated for a certain reference voltage, usually around 5V. If the reference voltage is different from that then the ECM is either going to think the car is too hot or too cold. My ECM thought the car was too cold and that it was never warming up. The ECM keeps throwing fuel at it because it thinks it is cold but it never sees it warm up. This is why it only ran good cold and terrible hot.

I replaced the ECM and it runs better than it did with the original plugs and tune-up parts. I'm not saying this is your problem but you wouldn't believe the fuel mileage my car got with the bad ECM, if it would stay running...

[yotoy82]

You make the best point on here. That's the one thing I always think about and fear is most likely the culprit here! But its kinda hard to diagnose a bad ECM because technically it isn't "bad" but not working "properly". Are they easy to change? I guess it wouldn't hurt to get one if can find a good deal on one somewhere. Because sometimes outta the blue, the car runs SUPER smooth and quiet and gets great gas mileage, and then it goes back to being its bad self again as if its a loose connection or wire somewhere.

I've spent a ton on this car already and plan to drive it another 5-7 years at least, I don't see what other item could be causing the problem except the ECM as well. Otherwise its a useless chase and people keep saying I must be driving incorrectly or saying thats just how the mileage is, makes me wanna say "here take the car and drive it yourself for two weeks and tell me how you feel at the end!".

But just curious, if the ECU/ECM is bad, wouldn't it show on the fuel trims?

Replacing the ECM is usually the last action in the diagnosis in anything the ECM controls when it comes to diagnosing through the factory books. Diagnosing the ECM is tough but is done by somewhat of a process of elimination. At first I had a slightly rough running car. I replaced the plugs, wires, caps and rotors with OEM parts. The car seemed to run slightly better but still somewhat rough and I just thought "Whatever..." Over a year later the car starts really running like crap and throwing a CEL for the engine coolant temp circuit malfunction. I replaced the engine coolant temp sensor for the ECM to really no avail, it still ran terrible. I have a Lexus tech buddy that works at a Toyota dealer and I was at whits end with the car. The next thing I thought was O2 sensors as they are original on 230k miles. We hooked the car up to a scanner and the O2 sensors appeared to either be going bad or the cats getting very very weak as the line should have been mostly flat and its was jumping a little at idle. Then he pointed to 2 mid 90's Lexus's sitting in the parking lot waiting on ECM's and we agreed that they seem to have issues with age and miles. We removed the glovebox and checked the reference voltage, which should be around 5V I think. It was over 8V.

The ECM measures temperature by resistance that comes from the temp sensor on the engine. To get a reading for the ECM it needs a reference voltage on each temp. circuit while the logarithm is calibrated for a certain reference voltage, usually around 5V. If the reference voltage is different from that then the ECM is either going to think the car is too hot or too cold. My ECM thought the car was too cold and that it was never warming up. The ECM keeps throwing fuel at it because it thinks it is cold but it never sees it warm up. This is why it only ran good cold and terrible hot.

I replaced the ECM and it runs better than it did with the original plugs and tune-up parts. I'm not saying this is your problem but you wouldn't believe the fuel mileage my car got with the bad ECM, if it would stay running...

Lucky you were able to sort your problem out, most people would throw the car away rather than spend time and money on diagnosing it.

The thing with mine is that it runs butter smooth 10 min after starting from cold, no shaking, no stalling whatsoever, I mean it drives great powertrain wise! I hardly know the car is running and it has great power and feedback. Oh well, maybe for its age mine is just how it is. I drove 150 miles the other day on the highway and got around 21-22 mpg with the ac on, driving at 68 mph the entire way. Hit city driving and falls back down to 11.4 mpg as usual! Guess Ill have to live with it for now until something acts up!

[yotoy82]

Blah, drove to Ohio a few weeks back (five hour drive) averaged 27 mpg. In the city, I'm getting around 9 mpg right now.. Yes, NINE!

I took it to the Toyota dealer, they checked the fuel trims and said everything is 100% perfect.

I'm stumped at this point. The car drives like a dream, (slightly bit noisier than our other two LS400's, like the resonance is off).

Its pretty bad when the gas tank is on E at 230 miles.

No idea why a car would perform flawlessly, get wonderful gas mileage on the highway, but totally klunk out in the city.

[curiousB]

Is the 9 MPG computed with a full tank of gas and then when empty filled back up and then computed on the exact odometer readings vs the exact fuel used?

The fact that you get north of 20 MPG on highway says nothing is wrong with drivetrain once engine is warmed up. That means either you do a lot of 3 block trips, you leave the car idling excessively, you are generalizing on MPG computations, or you have a EFI problem where the engine stays in open loop for an extended period when cold ( and intentionally runs richer). The latter could be the engine temp sensor for the ECU but usually when it fails it is a destructive failure so it doesn't correct itself once warm.

[yotoy82]

Is the 9 MPG computed with a full tank of gas and then when empty filled back up and then computed on the exact odometer readings vs the exact fuel used?

The fact that you get north of 20 MPG on highway says nothing is wrong with drivetrain once engine is warmed up. That means either you do a lot of 3 block trips, you leave the car idling excessively, you are generalizing on MPG computations, or you have a EFI problem where the engine stays in open loop for an extended period when cold ( and intentionally runs richer). The latter could be the engine temp sensor for the ECU but usually when it fails it is a destructive failure so it doesn't correct itself once warm.

Yes I'm calculating driving a full tank (reset the miles, calculate the gallons etc. by empty tank I mean I filled 19 gallons so not one hundred percent empty but does mean my fuel gauge is worki g because it does have space for thag much fuel) and so roughly 205 miles driven and 19 gallons gone (every time I gas up is always a fill up).

So varies from 9-11 mpg in the city. 25 on long trips and if I drive an hour on the interstate and mix city well. That's coming to about 15 mpg.

I drive about 25 miles short trips after filling up over few days and needle moves. Then after parking it. Needle has moved a lot more! No one is stealing gas from me and no leaks.

Probably 65 percent of my trips are about two miles back and forth to office maybe twice a day and sometimes a bit more for food local shopping. I never let car idle.

I do notice when the car is started first in the morning on cold days it's as if the engine is frozen. I give it gas but the car doesn't want to go its as if I am pulling a trailer and the sound isn't so great. It feels like crap! I use 5w30 thought of switching to 0w20 or something maybe to get better flow and warm up faster or get a higher temperature thermostat I have a feeling mine might be opening too soon but none the less on auto climate heat barely starts coming in 5 minutes and about 13 minutes from start the car seems like the engine has reached operating temperature.

[curiousB]

I would't deviate from oil type. It isn't the reason you have terrible gas mileage. There is something wrong here but it isn't oil.

Could be thermostat is stuck open and takes a long time to warm up engine. This maybe why long trips are efficient because the engine gets to steady state warm.

You've been struggling with this for a while. I'd go ahead and change the thermostat and maybe the engine temp sensor (ECU one no the dash sensor). This is DIY and not too expensive. If it does;t fix it you're not out too much $$$..

[SRK]

I do notice when the car is started first in the morning on cold days it's as if the engine is frozen. I give it gas but the car doesn't want to go its as if I am pulling a trailer and the sound isn't so great. It feels like crap! I use 5w30 thought of switching to 0w20 or something maybe to get better flow and warm up faster or get a higher temperature thermostat I have a feeling mine might be opening too soon but none the less on auto climate heat barely starts coming in 5 minutes and about 13 minutes from start the car seems like the engine has reached operating temperature.

From your description, I wonder if the T-belt is correctly timed? Perhaps both of the sprockets are out one tooth. I've worked on more than a few other brands finding the T-belt off one tooth - they idle OK, seem to run acceptably, but have no power and and just "soggy" feeling. Given all you've done, it will cost very little to confirm correct cam/crank timing.

SRK

[yotoy82]

I would't deviate from oil type. It isn't the reason you have terrible gas mileage. There is something wrong here but it isn't oil.

Could be thermostat is stuck open and takes a long time to warm up engine. This maybe why long trips are efficient because the engine gets to steady state warm.

You've been struggling with this for a while. I'd go ahead and change the thermostat and maybe the engine temp sensor (ECU one no the dash sensor). This is DIY and not too expensive. If it does;t fix it you're not out too much $$$..

I put a new thermostat in shortly after buying the car, the old one wasn't in great condition, and the new one helped a lot. But it could have been a dud, but even when the car gets warm, the mileage stays the same around the city even in the heat of the summer.

I think I will go ahead and do the ECU Engine Temp Sensor, do you know the part number for a 1996 LS400 and where it is on the engine (tutorial anywhere)

I already changed the engine coolant temperature sensor, is this the same one you are talking about?

I do notice when the car is started first in the morning on cold days it's as if the engine is frozen. I give it gas but the car doesn't want to go its as if I am pulling a trailer and the sound isn't so great. It feels like crap! I use 5w30 thought of switching to 0w20 or something maybe to get better flow and warm up faster or get a higher temperature thermostat I have a feeling mine might be opening too soon but none the less on auto climate heat barely starts coming in 5 minutes and about 13 minutes from start the car seems like the engine has reached operating temperature.

From your description, I wonder if the T-belt is correctly timed? Perhaps both of the sprockets are out one tooth. I've worked on more than a few other brands finding the T-belt off one tooth - they idle OK, seem to run acceptably, but have no power and and just "soggy" feeling. Given all you've done, it will cost very little to confirm correct cam/crank timing.

SRK

You know... this is something I was thinking about too. the owner spent a TON of money over maintaining this car, and it was odd that he spent the money changing the timing belt and then a few months later sold the car. I was thinking maybe the toyota dealer he went too didn't do it properly.

I got the spark plugs changed recently and it was written on the receipt checked timing or something of that nature. Is there a different timing for spark plugs or is checking the timing a standard thing to do after changing spark plugs?

How does one go about checking the cam/crank timing and how much does it cost roughly? Do let me know, and thanks for the replies guys!

Edit: I guess cam/crank timing is different then ignition timing. How does one check the cam timing, the LS400 looks complicated, would it have to be taken apart?

[curiousB]

How does one check the cam timing, the LS400 looks complicated, would it have to be taken apart?

Its pretty easy actually. Just remove the top timing belt covers to expose the camshaft belt pulleys. Then get a socket and ratchet (or maybe a bar)and turn engine to TDC. The cams should align exactly to some marks on them and on the cover behind them. If they don't turn crankshaft ome more full turn clockwise and recheck.

It should be obvious if the belt is misaligned. A tooth offset would be about 1/4" error on the marking points.

[26Gator]

Maybe this is an old post and you've gone past the issue, but I did not see anyone suggest fuel injector cleaning. I just sold my 1995 LS400 with 129k and it was still getting 19/24 city/hwy mileage so your's should be close to that - perhaps 17/20 with the 200+k miles. I was having some mild smoking with startup after the car sat for a few days. Service advisor suggested that I spend the money to have the throttle body and injectors cleaned before worrying about head gaskets, rings, cylinders and the like. Sure enough, that took care of the issue. Surprisingly, I did not see much of a drop in the mileage although some months we did some hwy driving and other times just town driving. I try to always get good filtered gas (Costco) or one of the Top Tier gas fillups when I'm on the road. (Shell, Texaco, Chevron typically). I'm also assuming you do use Premium gas and not skimp on the detergents and octane with 87-92 octane gas. The higher compression engine burns the higher octane with its higher detergent content much better than using regular and/or poorly filtered gas. These comments are NOT provided with any degree from Mechanical or Automobile Engineering - only personal research and discussions with "those in the know".

[SRK]

Ray, raising the issue of octane around here is extremely perilous. Far too perilous....

[yotoy82]

Maybe this is an old post and you've gone past the issue, but I did not see anyone suggest fuel injector cleaning. I just sold my 1995 LS400 with 129k and it was still getting 19/24 city/hwy mileage so your's should be close to that - perhaps 17/20 with the 200+k miles. I was having some mild smoking with startup after the car sat for a few days. Service advisor suggested that I spend the money to have the throttle body and injectors cleaned before worrying about head gaskets, rings, cylinders and the like. Sure enough, that took care of the issue. Surprisingly, I did not see much of a drop in the mileage although some months we did some hwy driving and other times just town driving. I try to always get good filtered gas (Costco) or one of the Top Tier gas fillups when I'm on the road. (Shell, Texaco, Chevron typically). I'm also assuming you do use Premium gas and not skimp on the detergents and octane with 87-92 octane gas. The higher compression engine burns the higher octane with its higher detergent content much better than using regular and/or poorly filtered gas. These comments are NOT provided with any degree from Mechanical or Automobile Engineering - only personal research and discussions with "those in the know".

I did a 3 step fuel system cleaning... One bottle in the gas tank, throttle body cleaning, and some kinda chemical they ran through the engine with a vacume pipe for a while. I dont think it would be too easy to literally take the fuel injectors out of the car.

[yotoy82]

How does one check the cam timing, the LS400 looks complicated, would it have to be taken apart?

Its pretty easy actually. Just remove the top timing belt covers to expose the camshaft belt pulleys. Then get a socket and ratchet (or maybe a bar)and turn engine to TDC. The cams should align exactly to some marks on them and on the cover behind them. If they don't turn crankshaft ome more full turn clockwise and recheck.

It should be obvious if the belt is misaligned. A tooth offset would be about 1/4" error on the marking points.

Ill be having a mechanic at the dealer do it for me. I know the timing belt service is quite expensive. So it shouldn't cost a lot to just have them remove the cover and have a look?