Timing Belt Jumped

[stufadrummer]

"IF NOT INTERESTED IN THE WHOLE STORY AND JUST WANT THE MEAT SKIP FIRST POST"

186,xxx miles

1992 lexus ls400

i have belonged to my.is since 2008 and owned my 2003 is300 since 2007 and have owned my ls400 since late 2010 and i really love lexus/toyota and have done all my own work i even rebuilt my 2j on my own with no issues runs like a dream ............. thanks to my.is and now LOC u are also in my back pocket

Hello LOC members this my first post to your fine forum filled with loads of great information thank you. well after a week straight of reading forums on everything from a plugged cat to numerous ingnition related faults, timing belt issues, ecu failures, etc. i was finally able to diagnose my problem.

but first i would like to tell my story. It all starts out i go to buy new rear tires as my room mate borrowed the car and hit a 2x4 on the free way popping one tire immeadiately put spare on, bought used temporary tire. 4 days later passenger rear goes put spare on. Sitting on the side of the freeway at the time starter decides to die. Got AAA home, replaced starter in 2 full day of work PITA put car back on road started and ran fine like usual. a week goes by driving on used tire and full spare got brand new rear tires $230 (i am on 19's) go directly home park car in drive way hour and half goes by i

decide to go to store get in start and put in reverse i notice a shaking coming from the engine like its struggling but its idling beautifully kinda of so i countinue i push the gas to back up which make me check the parking brake, its off. put car in drive let off brake car does not move push gas and it feels like a restriction in exhaust or intake so i pull back in to drive way shut it off. My friend comes over another mechanic he goes on test drive with me so we pull into street and its doin same thing. This time i drive to end of street and back now it smells like sulfur and rotten eggs we both say at

same time bad cats (boy do i feel like an idiot in hinesight) but any ways i imeadiately go buy universal cats $103 each have installed next day at exh. shop for $157. car is still doin same thing no power horrible. AT THIS POINT IM QUESTIONING MY 8 YEARS AS A MECHANIC, for not waiting and properly diagnosing the real issue. Car is super rich and in limp mode (with no check engine light on) running on 4 cyl. well without the check engine light and thru use of my good ole multimeter i was able to diagnose a bad ignition coil on the passenger side. I figured since i had been DD'ing this car

for over a year. a full tune up wouldnt hurt so i bought two ignition coils, two rotors, two caps, (plz dont yell at me yes duralast) new wires and NGK ix iridiums probally should just got double plats. finish up with no real issue ----->broken clips<-------- car is all back together. starts up first try easiest startup she has ever had, pull out of drive way feels great put in drive with about 10% throttle she wants to take off whoa girl. i hold back and drive her with ease just to see how things feel everything feels perfect come back home park turn her off. clean up my tools put my lights away close up the

house get back in car since i have to pick a friend up from work. i go to the corner of my street make a right and i decide she feels good lets see how she picks up so i give like 80% hold shift 100% she dies. feels like i ran out of gas DOAH coast thru intersection pull off to side of road while doing the running car ( where you run with the car holding the wheel and the door hoping you dont trip). Get car to safe location off road walk back home 1/4 mile. grab gas can and my 97 ford ranger go to gas station get one gallon (should have grabbed the 5 gal right) put a gallon in it still wont start. go

pick friend up from work in ranger come back helps to tow the ls400 back to the house next day my week long head scratching diagnosis began

so i ran thru everything checking every sensor, relay, fuel pump, iac (well get to something about this i got a ? for later) all sensors check out, atleast sensors that would stop car from starting. i knew that the MIL should turn on when KOEO but it did not had me really thinking i had a bad ECU i was almost 100% this was my problem but i continued to dianose than i read a post about the bulb burning out (*jeebes help me) so i switched the brake indicator buld and sure enough my MIL light came on like it was suppose to. jumped the connector but of course no codes comp had been reset

already from unplugging battery during tune up. i tried to turn car over like a buch of time with a freshly over night charged battery. no MIL being set took a day off cause i wanted to burn her (i couldnt doit i love her) so i was goin to take a another day off today but i couldnt help it. outside under the hood by about 10am (4 day earlier i stayed up all night reading and googling and out under the hood by 5:15am worked to night fall no prevail) so after standing there i think there is only one thing left i havent checked ( naw couldnt be mmmhmm) maybe i jumped a tooth when i went full throttle

so i proceed to take the covers off and check timing ( should of been done day one) well sure enough line up the crank at 0 turned many a times to make sure but passenger side cam mark when it is suppose to sitting at 2'o clock was sitting at about 10; driverside mark suppose to be like 10 was sitting at 7 so sure enough i had jumped what i estimate to be some where around 8 to 10 teeth slipping down by the crank gear

so i found my problem jumped time really bad causing no start with good fuel and spark. so i tear her down and sure enough i get down to just the crankshaft gear and the guide that hold the timing belt in place, the cast coming off the engine had broke wedging between belt and gear. the cause of the guide breaking was from a metal sleeve located in the passenger side plastic cover the goes over plugs and cam, metal sleeve that the bolt goes through middle of engine side of cover had fallen out and down the black hole that leads to the crank gear.

i have noticed that this sleeve was missing a long time ago like a year ago i had no clue it had fallen in the black hole but i guess it was out of the way untill all the shaking and jiggling of me wrenching on her knocked it loose and to its final destination my crank gear.

so now the water pump (since i was there) and the timing belt have been replaced. all debris have been cleared and cleaned got new belt on with no issues turned over engine by hand multiple time all marks now line up i ran out of day light and am now forced to continue tomorrow i got the crankshaft pulley back on just got to finish in the morning i will have update tomorrow night.

i apologize for the long post i have just had all this on my mind and really wanted to get it out and share my experience. also i have read a lot of questions about people who have had their timing belt fail in a extreme way. well i would say that 8-10 teeth off is pretty extreme. as i am not finshed i will let you know if i have any engine damage but i am goin to assume and say since this motor in non interference i think i will luck out with no major damage

now the ? i was referring to eariler has to do with IAC or ISCV but i ohmed out the windings and they fell within spec i did the bench test no movement just a shake i cleaned it up cause there was a lot of carbon build up redid test still no movement. my idle has always been fine and no long starts no shakes nothing no signs ever of anything wrong am i just that unlucky that my IAC is probally gonna be bad when i get done with all this?

[curiousB]

Is there a question here?

[stufadrummer]

sorry i wrote this post last night i was pretty tired my point of this post was more to give my experience. i had mis diagnose a bad ignition coil, vehicle only running on 4 cylinders. as a bad catalytic convertor which i was wrong. i then thought i had a bad ecu or sensor somewhere. i wasted alot of time trying to chase down a problem that wasnt the culprit. i even cut rewired and soldered the left trunk hinge wire bundle ( although i did find 4 bad wires with opens in them there). In the end after taking a step back and some time off i was able to logically approach the problem. and discovered that i had jumped timing 8-10 teeth

i was hit with a lot of problems got me flustered ; popped tires followed by dead starter , ignition system failure (misdiagnosed as bad cat) followed by severly jumping timing.

really the only thing that helped me get all this fixed was lexusownersclub Thank you

my point is this car can get really expensive to just start throwing parts at and i learned that the hard way

the question in the forum is have you seen the ls400 idling fine although the IAC failed the bench test?

im keeping my fingers crossed that when i am done the IAC dont need replacement since that is a $1000 + item new and i have already dumped over a $1000 into at this point

hopefully my experience is of use to some one. agian sorry for the endless rant

[stufadrummer]

so i finished up the timing belt and buttoned everything back together she started first try but i did have to hold the gas pedal if i let go of the gas pedal she dies. i took her for a drive she drive fine with no loss of power and no hesitation only issue i have now is she starts and dies unless im holding the gas pedal

i have no check engine light although when i went for a ride it did come on but that may be the engine dieing from me not holding the gas but the check engine light does not stay on and no codes

i also noticed when i turned my headlights on my dash dims when i turn the headlights off dash brightens up

i did replace some wires in the trunk on the left hinge i ohmed out the new wires and there was 1 ohm of resistance in the length of new wire i used, Could this extra resistance be causing my dimming dash problem?

could my car be dieing out because of a bad IAC (which is what i am assuming since it did fail bench test but passed the resistance spec.)? and i did take off my TPS to check it. Could a improperly adjusted TPS be causing my dieing out issue? and last thing im thinking could timing be slightly off and causing my dieing out issue?

i guess i have some more reading to do but any help would be very much appreciated. and thank you in advance

[landar]

Wow, thats one hard post to get thru, Brandon. I am just guessing at the dash lights but wouldn't it make sense that the Lexus engineers designed the dash lights to dim when the headlights came on as they assumed it was getting dark outside? That's the way most systems work.

On the other issues, take a look at this site to check your TPS -> http://www.lexls.com/tutorials/EFI/tps.html

[stufadrummer]

Wow, thats one hard post to get thru, Brandon. I am just guessing at the dash lights but wouldn't it make sense that the Lexus engineers designed the dash lights to dim when the headlights came on as they assumed it was getting dark outside? That's the way most systems work.

On the other issues, take a look at this site to check your TPS -> http://www.lexls.com...ls/EFI/tps.html

hey thanks for the reply on the dash issue i feel alil stupid i went out and checked the dimmer and it was turned down i turned it up and dash brigthened up. i am gonna try to readjust the TPS see if that helps me before i jump and go get a IAC

sorry about such a hard post i have re read it and now relize i probally should of cut out a lot of the fat but thank you for taking the time to read thru

[landar]

You are welcome. Working on cars, interacting on forums is all a learning process. You are doing fine. Just limit the size of any post to a couple of shorter, concise paragraphs and you will get more responses. Most people, upon seeing a monster post, just go on and never bother reading it.

[stufadrummer]

thanks for the advice well keep in mind on future posts

i tried readjusting the TPS both ways first with a multi meter and some jumper wire i took from a honda junk harness for the map sensor connector just took the individual pins out perfect fit each female mini connector fit the pins of TPS snug.

and i tried turning the TPS all the way clockwise (suppose to make a high idle) car still dies

last thing i did was tighten the throttle cable did not help just made RPM's jumpy car still die no matter how much i tighten the cable so i put back to original postion

i pulled the IAC apart again and since it is passing its windings resistance check i checked the bearings out and the rear smaller bearing seems to be sticky causing the IAC to not snap back like i am assuming it is suppose to. According to the service manual your suppose to hear a snap/click sound when you shut the car off which i dont hear.

has anyone attempted to replace this bearing it does have a part # number on it ill update later when i take it off again.

if replacing this bearing could be a fix it could be a lot cheaper than the $1000 price tag the IAC carries new

[billydpowell]

landar is right, any post that long, either you dont know how to explain it, or you have more wrong than I would know how to help you with..

[stufadrummer]

ok so alil up date i start the car at about 2pm it starts than dies i keep alive with gas and drive slow with two feet to store park and turn her off

come back out starts with out gas pedal and idles on its own drive home with one foot. Brake and go a few times idles perfect does not die

let sit in drive way while idleing to get to operating temp idles fine for first 2-3 min than starts to jump the RPM around up to 1000 RPMs down to 200 RPMs settles at 650 RPMs for amin or less jumps around again but does not die

get to operateing temp check engine light starts to come on and than go off car dies

restart without gas pedal steady RPM around 750 RPMs starts to jump around. check engine light come on when jumpy. steadys out light goes off car dies

jump connector get code 31 airflow meter but i dont believe this is right. Im thinking the IAC (which failed bench test) (IAC can not throw a code) is intermittenly going in and out causing a fluctuation in airflow making the ECU see an unsteady reading and causing ECU to throw airflow code

also maf passed alll multi meter spec checks but am goin to try the frequency test again if i can get the car to stay on and replicate the fluctuation of RPMs

[stufadrummer]

landar is right, any post that long, either you dont know how to explain it, or you have more wrong than I would know how to help you with..

i tried to explain exactly what happened to me over a month period in one post and it didnt work out so well. So im goin to edit that post and put "IF NOT INTERESTED IN THE WHOLE STORY AND JUST WANT THE MEAT SKIP FIRST POST"

you think this might help

[landar]

Oh Brandon, do not question the almighty computer. You may have a MAF sensor that is acting up. Maybe a vacuum leak. Check those areas carefully.

[stufadrummer]

only reason im questioning comp. is because it is unable to trip code for IAC not in its logic and since IAC directly effects idle flow rates it would adversely make the airflow meter have an unsteady frequency making the ecu believe the MAF to be the cause for its troubles (just a thought)

i have checked for vacuum leaks both by ear and starting fluid and find nothing

im taking a trip to the junk yard tomorrow hopefully maybe i can get lucky and find both a MAF and an IAC .. lets see if i can get really lucky find both and both be in working condition lol i did find an IAC on ebay for $74 but alil hesistant to order in fear of recieving a bad part although the guy is rated as a top seller

[stufadrummer]

so my problem is still there but now its acting differently

now when i start the car cold it idles just fine, drives fine no issues

once the car reaches operating temp my idles wants to die off

when the issue arises am im driving or coasting i can feel the car want to jerk but only when im not touching the gas

[curiousB]

I don't have time to read the novel here but poor idling is typically a vacuum leak, dirty throttle body, and/or dirty/sticky IACV. I'd run those to ground befoe chasing a compression conspiracy theory. Its usually the simple things, not the complex ones with these cars.

The fact you can fix it by pressing pedal some suggests its just not getting enough metered air.

[stufadrummer]

I don't have time to read the novel here but poor idling is typically a vacuum leak, dirty throttle body, and/or dirty/sticky IACV. I'd run those to ground befoe chasing a compression conspiracy theory. Its usually the simple things, not the complex ones with these cars.

The fact you can fix it by pressing pedal some suggests its just not getting enough metered air.

so that pretty much leaves me with air filter, MAF, IAC, vacuum leak thanks curious B for taking alil time though

biggest thing that gots me confused is that it runs perfect untill it reaches operating temp. then my problems start

[SRK]

I figure I'll toss in a few on this one.

The IAC is an output device - it responds to commands from the ECU to maintain idle speed ( varying conditions like hot, cold, AC on etc.) So you've got that part backwards. You're looking for an input problem, which as others have said could be a vacuum leak.

If the problem does not appear until the engine warms up and goes into closed loop, then you have to look at those things that make closed loop possible, like the O2 sensor. And a vacuum leak would make the O2 sensor go nuts once it's contributing.

As far as I know the IAC does pop a code, just like any other device signalling or controlled by the ECU. For sure on OBDII there are codes for it.

[stufadrummer]

I figure I'll toss in a few on this one.

The IAC is an output device - it responds to commands from the ECU to maintain idle speed ( varying conditions like hot, cold, AC on etc.) So you've got that part backwards. You're looking for an input problem, which as others have said could be a vacuum leak.

If the problem does not appear until the engine warms up and goes into closed loop, then you have to look at those things that make closed loop possible, like the O2 sensor. And a vacuum leak would make the O2 sensor go nuts once it's contributing.

As far as I know the IAC does pop a code, just like any other device signalling or controlled by the ECU. For sure on OBDII there are codes for it.

very good input SRK . i checked all possible codes for OBD1 and IAC is not a possible code. im starting to think i got a vacuum leak i cant find. but i will keep looking

[landar]

i have checked for vacuum leaks both by ear and starting fluid and find nothing

I believe that you are to use propane gas, not starter fluid when trying to identify and pinpoint a vacuum leak.

[stufadrummer]

both should work i have used starting fluid before and found leaks. i do got propane so ill give it a try see if there is a diference

[fsuguy]

How is your fuel pump/fuel pressure??

[stufadrummer]

i had thought the fuel pump might be an issue i cant find a service port on the fuel rail so i just cracked the lines and got lots of spray. The car has no issues accelerating lot of power there so i dont think fuel is an issue. thanks for the input fsuguy