91 Ls400 Cranks But Will Not Start

[shatcher80]

Recently car ran hot so had the water pump changed and timing belt replaced. After this the car wouldn't start and wasn't getting any fire. Triple checked the timing no car is getting spark, turns overs, but just will not fire. Check for code and got 14 Ignition signal no. 1, 15 Ignition signal no. 2. Yesterday car still wasn't getting any spark so I replaced the distributor, rotors, igniters and crank sensor. Removed the previous code and tried to start. I then got continous spark but still will not fire. Rechecked for codes and CEL just flashes with no codes stored. At a complete loss.

[curiousB]

Is this car worth it?

Based on your threads since July you've done the following:

1) Replaced MAF

2) Replaced fuel pump

3) Replaced the TPS

4) Replaced water pump

5) Replaced timing belt (not sure if you did new idler pulleys and tensioner with it)

6) Replaced distributors, rotors, ignitors and crank sensor

This guess and swap parts can get expensive. I think you need a new mechanic.

Is this the same issue you mentioned in this thread:

...http://us.lexusownersclub.com/forums/index.php?showtopic=66422&st=0&p=419065&fromsearch=1entry419065

[shatcher80]

Is this car worth it?

Based on your threads since July you've done the following:

1) Replaced MAF

2) Replaced fuel pump

3) Replaced the TPS

4) Replaced water pump

5) Replaced timing belt (not sure if you did new idler pulleys and tensioner with it)

6) Replaced distributors, rotors, ignitors and crank sensor

This guess and swap parts can get expensive. I think you need a new mechanic.

Is this the same issue you mentioned in this thread:

...http://us.lexusownersclub.com/forums/index.php?showtopic=66422&st=0&p=419065&fromsearch=1entry419065

Yes the car is worth it because some of the parts I replaced weren't the problem (MAF, TPS). It is just a matter of troubleshooting. My car is a 1991 and it has all of the original parts. They are in need of replacement after 19 YEARS!!!!!. I know this has got to be something minor I'm just not sure what.

[Dannymcenrow]

Yes it's good to replace parts anyway for prevention later on.

Me myself I replaced the fuel pump,Coil pack just for peace of mind.

Now I got to replace the Maf it failed already but I cleaned the connectors and the problem went away but I want to change it anyway.

[curiousB]

Would you get hip replacement or knee replacement surgery just because you hit 59 years old? Then why would you change parts that haven't failed in your car. I can see it for oil, tires, brakes, and other fluids. I don't recall reading MAFs wear out. It doesn't hurt to replace some things on a schedule but its costs more to change things before they fail (when they may never fail).

[curiousB]

Recently car ran hot so had the water pump changed and timing belt replaced. After this the car wouldn't start and wasn't getting any fire. Triple checked the timing no car is getting spark, turns overs, but just will not fire. Check for code and got 14 Ignition signal no. 1, 15 Ignition signal no. 2. Yesterday car still wasn't getting any spark so I replaced the distributor, rotors, igniters and crank sensor. Removed the previous code and tried to start. I then got continous spark but still will not fire. Rechecked for codes and CEL just flashes with no codes stored. At a complete loss.

Can you clarify to help narrow this down. Did the car run after the TB and water pump were replaced? Or has it never run since that repair? Are you doing the work or is it a mechanic? Dealer or Indy? If Indy does he have Lexus experience?

If it has never run I suspect TB wasn't lined up properly and timing of camshafts to crankshaft is off. I'd take top covers off and turn crankshaft to TDC and see if marks on Cams point to their respective timing marks. If not turn crankshaft one more turn and recheck. If still not on proper marks then you have TB mis aligned. Should be fairly easy to fix. Remove belt a redo install.

If it ran fine after TB job then maybe it is ignition. Not sure why you changed so many items at once. You bring more uncertainty into the equation when you touch many items at the same time. Obvious first check is to see you didn't mess up plug wiring. You claim you are getting spark. Maybe you need a timing light to see if #1 cylinder is sparking at proper timing point. Even if one bank of distributor was dead you should still be able to start it. It will run rough and no power but at least running.

If you think spark is fine then maybe spritz some starter fluid (ether) into air intake while cranking to see if engine catches any. If so then it indicates fuel not getting through. Fuel pump fuse, fuel pump, fuel pump safety shut off switch, blocked fuel filter (although it hard to see how filter would effect starting, typically more of a lost power symptom)...

Not really sure where you sit and if you're doing the work or commenting on the work of another.

[Dannymcenrow]

Yes Maf sensor do go bad I work at a car dealrship so I know exactly what goes bad at what mileage.

Most coil packs seem to last for about 80k miles some go till 100k and fuel pump also.

The Maf sensor will go bad because th connectors get dirty and short out the sensor.

That's what happened to me.

And actually I was going to replace the Maf but a guy I know who works at a garage that repairs different kind of cars told me that it's a common problem with Lexus that the connectors go bad to just clean it and maybe it will work again.

He came with a fluid I don't know what it was cleaned the connctors and put it back.

THe car wa RUNNING FINE the the CEL wen't OFF.

[SRK]

Yes it's good to replace parts anyway for prevention later on.

Me myself I replaced the fuel pump,Coil pack just for peace of mind.

You must be a favorite customer down at the parts store.

Trying to predict failure times is a mugs game - you can't do it.

I use skill to diagnose which component has failed, but only after it has failed. Imagine that.

But you carry on throwing parts around - and one day when something actually does fail....you won't have money to fix it.....

[curiousB]

Yes Maf sensor do go bad I work at a car dealrship so I know exactly what goes bad at what mileage.

I couldn't disagree more. A MAF is a light bulb. Yes a wire filament that has a current passed through it proportional to the air moving past it. Its configured in a bridge arrangement to permit accurate measurement but make no mistake the element is behaving like a light bulb without the glass. Would you change a light bulb before it burns out?

I can maybe get slightly on board with planned change out for mechanical elements that wear out like a timing belt, water pump, or fuel pump. But electrical items either fail early (infant mortality) or fail randomly. Warranty is meant to cover you on infant mortality. There is no way to predict random failure other than to experience it.

The only way I would change a MAF or a coil is if it failed. I guess this is why dealership repairs can be so costly. Changing things that aren't in need of changing.

[Dannymcenrow]

Oh yeah?

Well let me tell you this CAR NEVER BROKE DOWN WITH ME on the road.

Only onc I had stallin problem when the Maf sensor had problems but m car is in it's best shape.

I'm almost the only onethat has a 90's ca in this good shape.

When I changed the fuelpump I noticed that the engine became more responsive so mine was already weak waiting to go out.

That doesn't mean the car is completely fail safe but if you know something IS GONNA FAIL why wait till it fails and leave you stranded on the side of the road.

Till now I never had car trouble tat left me stranded by the side of the road but I know a lot of people who did because these parts fail.

There are parts tha always fail aroun certain mileage.

[VBdenny]

Not to ruffle anyone's feathers but I have to agree with Curious. My 1990 has 182,000 miles and has both the original fuel pump and MAF. Sometimes things do fail on a predictable pattern but not always. I follow this rule, if it ain't broke, don't fix it, and if it is broke, you can't break it. Not to say I don't do PM but replacing parts that might go bad is excessive. Now to qualify this I will add that IF I used the car on a regular basis for OTR, I might do what was suggested, but for general and around town, nada. At some point cars reach a point where you really have to consider finacial reality.

[SRK]

Oh yeah?

Yeah

Well let me tell you this CAR NEVER BROKE DOWN WITH ME on the road.

Neither has mine

Only onc I had stallin problem when the Maf sensor had problems but m car is in it's best shape.

Mine has never stalled

I'm almost the only onethat has a 90's ca in this good shape.

How do you know? My car is better than yours.

When I changed the fuelpump I noticed that the engine became more responsive so mine was already weak waiting to go out.

Self-fulfilling prophecy and anecdotal evidence (find your dictionary if you have one)

That doesn't mean the car is completely fail safe but if you know something IS GONNA FAIL why wait till it fails and leave you stranded on the side of the road.

Stuff happens

Till now I never had car trouble tat left me stranded by the side of the road but I know a lot of people who did because these parts fail.

I've never been stranded myself.

There are parts tha always fail aroun certain mileage.

Not always.

If you did what you claim to do as a mechanic, to real customers, you would be guilty of fraudulent behaviour, and at the right price a felony offense.

[Dannymcenrow]

Oh come on why do we have to start this?

Look The maf sensor is like a light bulb right?

Well a lightbulb is made to burn a certain amount of hours but the reason why people don't change them before they burn out is because nobody has an hour meter on their light switch to count how many hours the bulb has burned.

But some people do.

Look I have a DLP tv in the livinroom.

That one uses a DLP bulb because it's a rear projection tv.

That tv DOES have an hour meter build in.

You reset it when you change the bulb and it counts and when the bulb is about to go out a light will start flashing on the tv telling you that it's time to replace the bulb.

If you ignore it then one day you'll turn on the tv and you've got no picture.

It's the same with cars.

Things go out at certain mileagebut not only mileage but age is also a factor.

Some parts go with age and not mileage.

I work at a car dealership and I can tell you I saw '90s cars with 80k miles that already has a bad crankshaft and the same model but like year 2000 with 200k miles still going strong.

And don't say you're car is better then mine you haven't looked at it and if you take a ride in it you'll be amazed by the ride quality.

Everybody that rides in my car thinks it's amazing that a car this old can run so nice it's in NEAR NEW CONDITION.

When the car is cold it starts up perfectly.

You've just got to put the key in the ignition and turn it over don't even TOUGH the gas pedal it will start and keep running WITHOUT giving gas.

This on a car with 145k miles.

I use synthetic oil that's whats keeping the engine in top shape.

If you give it gas the engine still has a LOT OF POWER and doesn't LEAK ANY OIL.

Did I mention I use synthetic?

Now tell me who's got a car in this kind of condition.

This has been my sister's car since 1997 she really took great car if it she sold me it around 4.5 years ago and it still drives like the day she got it in 1997 as a certified pre owned car.

All 90' cars I see on the road are beat up IF THEY ARE STILL on the road.

Most cars has already reached their big end and can't be driven anymore.

Most of the time when I see a 90's car I see them broken down at a traffic light or by the side of the road.

A few weeks back I even saw a guy I knew WAY BACK years ago he was stuck in is Geo Metro Istopped and helped him push it off the road.

The other day a friend came to visit my son he has a Neon a 1996 Neon he went to start it and the thing wouldn't start.

But even if it starts it never starts on the first try and the engine definitly sounds like it's had it's better days.

[Wallybally]

To be very clear: the LS400 dies NOT have a MAF sensor. It has an Karman Vortex Sensor, which was priced around a 1000 dollar when it is new. It does not goe bad very often. Do NOT clean it, you will break it. A normal MAF sensor has resistor wires that hang in the airflow, that change resistance with heat, so the ECU can calculate how much air is getting through. The wires get dirty, you can clean those. The Vortex sensor has a post with some foil inside that is flapping in the wind, generating a frequency, by which the ECU can calculate the air flow. if you try to clean that, you will ruin it. If it fails, the ECU will go into a ‘get home mode’ and run very poorly. I would rather look at the anti-theft module or something.

 

W.

[vissine]

Below is the link to one of the experienced LS owners: LS400 areas that may fail. Hope the information helps somebody. The takeaway for me is according to this post, if your car is 95 or later, you can clean the MAF. 

Quote

List of LS400/SC400 areas that may fail - if you have a problem with the car, the issue should be here, so you don't have to pay someone to play a guessing game on finding the issue.

Make sure to use the genuine Toyota part purchased from a dealership - negotiate a 20-33% discount. Do not but parts on ebay, amazon, etc. - they will be counterfeit. If a Denso part can be purchased through Advance Auto Parts (authorized dealer) at 35-40% off the price, which is much less than the dealership, sometimes a 1/4 of the dealership price, I will mention it in the comment beside the part. Resist the urge to buy some Chinese trash part at AutoZone etc. - you will just have to go back and fix it with a high quality part in a few weeks or months if you want to keep the famed Lexus reliability and durability!

• Transmission mount - cheap, easy to install, and makes a wonderful difference in the way the car feels!

• Strut bars - the most common steering/suspension issue - fairly low cost, make sure that final torquing is done with car on the ground.

• Main ECU - contact me for the only correct rebuild in USA, typically affects '93-'97 models primarily, '98-'00 are also affected. '90-'92 are also affected but the ECU core will not be damaged, this is a big savings, because it means your original core can definitely be rebuilt, it will not have corrosive damage like the '93-'00 years above can get.

• Power steering leaks - these will take out your alternator if not dealt with, the good news is that it is either an O-ring or a hose, NOT the expensive rack!

• Idle air control valve - I rebuild these for a small fraction of the the new part cost. - the bearings can go bad after 20+ years. If your ECU is good and idle is not right, this may well be the cause.

• Cracked wire in harness - in driver's side sharp bend in trunk hinge - if you have weird electrical or lighting issues, this may be the culprit, typically only affects '94 and earlier.

• Upper control arms - contact me, I might have a way to save some money on this one, it's expensive.

Cigarette lighter fuse (inside lighter socket) - a DIY delete job, no cost - read up on Club Lexus.

• Tilt steering failure - this can be repaired at no cost, you need a small plastic washer or a zip tie to replace original washer that disintegrated - see Club Lexus or Youtube

• Fuel pump control ECU - contact me, I rebuild these for a tiny fraction of what the part costs at the dealership - there is a test you can do by temporarily jumping around it. See Club Lexus post by Yamae.

• Valve cover leaks, this is pretty straight forward, you can put this one off and just keep close watch on the oil level. LS400's do not burn oil, but they can leak it!

• Starter - this one can also be expensive - the key here is not to ruin your starter by overheating it. - Don't crank the car for over 4 seconds at once, and give it a one minute rest between tries. If an LS400 will not start easily, find the problem, don't just keep cranking away!

• Knock sensors & Knock sensor pigtails - this is a rare problem, but has come up, especially on pre-'95 models.

• MAF sensor - generally extremely reliable, but early model LS400's ans SC400's used Karmann-vortex type sensor, and any solvent type cleaner will kill it! - unless your car is 95 or later, just use a dry Q-tip to clean!

• Vacuum lines, these are rubber and getting really old, they should be replaced before they leak and cause an expensive misdiagnosis. Any tight fitting vacuum line of the correct size is fine, the dealership part is not required. Make sure to replace these one at a time, so you don't get mixed up as far as where they go.

If the problem is not listed here, there is a good chance it is misdiagnosed.