hbasavar

2000 Lexus ES 300
149k miles

Hi everyone,

I was driving to work and sensed something wrong with the car. The car was idling at higher speed than normal and when I came to a traffic stop, it died completely. Restart attempt failed. Even to jump start it failed.

Today,I had the battery recharged and tested at Autozone and is fine. I also had the Alternator tested it is fine. The guy told it still could it be the Alternator as they do not test under load. What do you think?

Starter
Crank Position Sensor

Appreciate your response.

Thanks,
Hemanth.

LeX2K

Prime suspect is a broken timing belt does the engine sound different when cranking? If it's a bad sensor there will be a stored coded, not sure if Autozone will still read check engine codes for free but you need to get that done.

hbasavar

Thank you for your response. I will check the timing belt as soon as I put back my Alternator tomorrow.

hbasavar

Ok, today morning put back Alternator and cranked it up. It cranks but doesn't start. The timing belt is moving as I peer through the timing belt cover. I believe this eliminates Engine seize, Timing Belt and the Starter. I am going to check for the spark next. I am hoping that it is not the fuel pump. When I put the ignition switch to ON position, I do hear some constant sound in the engine bay which I am guessing, is the fuel pump.

Let me know if I can check anything else to narrow it down.As always, most appreciated.

Oro

It eliminates "seize" and starter but not belt. the belt can move but be out of time because of slack tensioner or broken pulley, or skipped belt.

3 things make an engine go: spark, fuel, compression.

take out a plug and ground it on the chassis. Have someone crank. See spark? Smell fuel from cylinder? If so, you have eliminated 2 of the three.

now focus on compression. You can have physical compression, but it be out of time - thus not effective compression timed with fuel and spark. This can be a myriad of reasons and I am inclined to think like Lexus2000, principal suspect is belt especially given spare details you gave - over-rev at stop then nothing. Classic belt failure. He asked if it sounded different. What he was hunting for was if the engine sounds like it's "freewheeling" when cranking and not chugging/compressing, that is important and why he asked about sound. That is important to help diagnose.

Nelexus88

The fuel pump is not in the engine bay, it is in the fuel tank in the rear. If the car is in a quiet location you may hear the pump run for a few seconds when the ignition switch if first turned on (but not cranking.the engine). A fuel pressure gauge is needed to verify the pump is operating correctly.

Did you determine if the engine has spark?

If you do not have a CEL light ON, then most likely, no trouble codes are stored in the computer to assist with the diagnosis of the problem. If it is ON then check for trouble codes.

rudyH

A quick check to tell if it's possibly fuel related is to spray starting fluid into the air intake PER THE INSTRUCTIONS ON THE CAN! Auto stores carry it. Sometimes called starting ether. Don't keep using it, don't think "more is better" or anything else. This is volatile stuff. Used properly no problem at all. Get stupid with it or keep using it over and over because you get all excited to hear the engine fire up for a second, and you can break a piston or connecting rod. For once, I don't know this horror from personal experience.

hbasavar

If I press on the gas pedal while cranking, it starts up. The cable that moves when the gas pedal is depressed is a bit loose. I am not sure why it became loose. Is there a way to tighten it?

Thanks again for all your responses.

PFB

Something else to consider especially if you recently filled it up, is that you could have gotten some contaminated fuel. Maybe water in the gas.

Just a thought.

Phil

rudyH

Occam's razor at work again! At least you have it kinda' figured out. So after it starts, it idles OK with your foot off the gas pedal?

Nelexus88

I doubt the loose throttle cable is your problem. The idle speed is controlled by the engine computer and the idle air control (IAC) on the throttle body. Since the engine starts when you depress the gas pedal, I would suspect your throttle body needs to be cleaned as they can build up deposits with high mileage. Most any repair shop should be able to clean it at a minimal cost or you can check Youtube for DIY instructions.

rudyH

Absolutely, but I am wondering if the TPS could be bad or need adjusting if it's indeed adjustable on that model. Just curious. Hard to fix things over the Internet.

lostape45

I'm guessing its your IACV or throttle body needing cleaning. Is your check engine light on? It may not even come on if it's just the throttle body getting jammed up.

ES300NZ

it won't be the TPS, .. that's just a very simple resistor, I've never seen one fail. (ok .. it 'could' be).

My guess, and it is a guess, .. there isn't much to go on, is something related to air measurement.

The engine's RPM rose, .. increased air flow, then it died and refused to start.

- possible massive vacuum leak,
- possible MAF failure,
- possible fuel pump pressure increase, / decrease / failure / it's seized.
- possible bad fuel (water in fuel).

if there is water in your tank, the simple fix is to add methylated spirits into the tank, that will bond with the water and allow it to be combusted. Water molecules are much larger than fuel and cannot pass through a fuel filter, so form a blockage. However when bonded with methylated spirits they can, and are simply burned off. The correct ratio of methylated spirits to fuel is about 10% (max), so that would be 1lt (not anymore), of methylated spirits, to 10lt's of fuel. Try it, it's a $2 fix.

Once added to the tank you need to drive the car to mix it properly, so start the car, drive it around a few corners or shake the car, and if it works the car should be running normally after 3-4mins of running time.

Timing belt: If the belt was broken, the car would not run. If the belt had slipped, the car WILL run if it was just one or two teeth, and perfectly fne, but not well, if more than one or two teeth, at three to four teeth running is questionable .. as in unlikely. It would start, then fall on it's face and be hard to restart. Irrespective of how many teeth have slipped (if any) It's behaviour would be a constant.

Throttle cables always have some slack, this prevents the rock of the engine increasing the engine speed. It's common sense.

Starting fluid doesn't always rule out fuel (or air), as a cause. Becareful with that stuff, it's quite dangerous in the wrong hands. My friend set himself on fire with that stuff once. It was damn funny, he singed his eyebrows, hair, and nose hairs (he breathed in mid fire), he's fine, just a bit wiser.

All of the symptoms could be caused by a bad earth wire. Bad battery. or water in the tank. A blocked fuel filter, bad fuel, or a bad coil. This car seems to require experienced diagnostics.

hbasavar

It was a stuck IAC valve. Just used Carb cleaner and rinsed it thoroughly and jiggled the magnetic rotating piston left to right until it was moving freely with ease. Put it all back together and it started humming just fine.

The valve wasn't real dirty either, but just minute particles made it stick.

Thanks to everyone for taking the time to help me out. Most appreciated. Special thanks to Nelexus88 and lostape45 for being right on the money.

Hemanth.