8 month misfire chase
05-11-23, 01:12 AM
#1
10th Gear
Thread Starter
8 month misfire chase
I have a 03 GS300 with multiple misfires. last i checked it was 2,3,4, and 5. 2 and 5 are consistent but others come and go. ill start from the beginning because ive already put pretty much all the parts that should fix it. ive read **** tons of forums and have not found a issue that fixed mine. i bought the car last year (22) in august. had 212k and pretty average condition for that mileage. first thing i did when i got home was check plugs and timing belt. belt was cracking so i knew it had to be changed. first part change was spark plugs and while i was at it i changed the wires and coil packs, all 3 of them ngk. car ran beautifully. i decided to do the belt change myself after watching and reading. i got the hks purple tuner belt from japan. i also got new water pump and the tensioner. i did the belt change and also all the front seals (both cams and crank). took 14 hours from 10 am to midnight. i triple checked the timing ( rotated the engine 9 complete times) and everything was square. started the car and it sounded very rough so i shut it off. it was running for about 7 secs. no noise or anything came from it. i was scared i was out of time some how so i called my brother who used to work on supras so he said hed get it back in time if it was off. he came by and we took it apart again and put it back together correctly. now he wanted to start it before we had put the harmonic balancer back on. started and idled perfect at 950 we let it run for about 30 secs to see if it changed and it didnt. so we put the serpentine belt back on and called it good. next morning i go out to start it and its right back to rough idle and running choppy.
i didnt really know what to do and i was scared it bent a valve or something when i started it for the 7 seconds. so i went to oreilys and got a compression tester. compression was MINT
Cylinder 1 - 182
Cylinder 2 - 180
Cylinder 3 - 165
Cylinder 4 - 165
Cylinder 5 - 181
Cylinder 6 - 190
that compression for that many miles is really good so i was a lot less worried. i then started to read around and see what common issues i couldve done. ive read about the crankshaft pulley and missing teeth, checked mine a million times and they are all still there, the belt washer thingy is there too. ive cleaned out the ocv filter from the banjo bolt and even put a new one in. i changed the ocv twice. first was a gates one then new oem. ive put a brand new oem vvti gear on also, still no change. ive read the coil connecter clips get old and broken and remembered one was broke so i put new clips and wires from what i could clip from the loom. all wires are soldered and thermal wrapped. all of these parts and nothing has changed.
i decided to drive around a bit and see if it would clear up. its a very very low idle about 100-200 and sounds like a motorcycle. has a very big hesitation starting when hitting the gas but once it passes 1500-600 something just clicks (not audible) and it just goes. seems to run fine but can tell theres major power loss and it would “redline” at 4500. the car wouldnt go past 4500 without sounding like 1000 screaming lawn mowers. the rpms also fluttered a lot while giving it gas. wasnt smooth increase. car sounded smooth going up but the guage kept going 3 steps forward and 2 steps back. i figured it might’ve been the IAC valve since that helps with idling and shuts off at 1500. i got a whole new throttle body (used from an is300 with 100k) since a new IAC is $300 and i got the throttle body for 100. throttle body made no change. while testing my radiator blew up so i put in a new denso one. cooling system is perfect. i realized my cat converters where glowing red after a short drive so i bought stainless headers and put them on. (since i figured it might be a bit to found out the issue i dont want a clogged cat being another problem). no change but the car is veryyyyyy loud since the bottom of the headers wont seat with the rest of the exhaust. i also heat wrapped the headers since i didnt use the og heat shield. i thought maybe a vacuum leak and changed all of the rubber hoses around the tb and intake plenum that was even somewhat tarnished. no change. i decided to go back to my brother at his mechanic shop and they told me to replace the ignitor module. i bought a new one from ebay which was oem and even came in oem packaging yet looked different than what i had on. i changed it and it ran more consistent. the rpms wasnt staggering and was smooth going up but not completely, once i hit 3500 it starts to stagger but a bit less. i thought maybe my intake with the air resonator being a common crack culprit. was very cracked on the bottom so i replaced with a makeshift one. theres a thread i followed on here that showed me. i took the sceptre pipe from oreillys and cut it and it fit perfectly. i also picked up maf cleaner and new air filter. still no change.
heres whats weird. i decided to change the serpentine belt cause it was old and there was a sale at autozone. i got a continental. i took the old belt off and thought of something. it ran nice when i had my bro come after i changed the belt. i started the car with no belt on and it idled perfect. i let it warm just until the coolant needle started to get in the readings. i put the new belt on and it went right back to “normal”, rough idle and sluggish. alternator also reads 14.5 volts
it is now 8 months later and ive put 10k miles on while its been running like this. ik ik its bad to do it but i haven’t had a “bad problem”. i need a car to get to work and this is all i have. it always cranks up and starts, no issue what so ever. doesnt get hot, no noises, no knocking nothing, ive always put in premium, never 87, and changed the oil every 3000, so 3 times. im truely stumped. sorry for the long explanation but i feel like the more details the better. i just got home from work and its 2 am so im going to bed. hopefully somebody sees this overnight. PLEASE PLEASE HELP
also i scanned the car last night and i got a p0011 and a p0016. those arent the only codes, obviously the misfire ones too. the filed attached is a video showing the low idle and the 1500k click. it clicks at 1000 cause its not in gear so not under load. its loud cause this is after the header changed.
i didnt really know what to do and i was scared it bent a valve or something when i started it for the 7 seconds. so i went to oreilys and got a compression tester. compression was MINT
Cylinder 1 - 182
Cylinder 2 - 180
Cylinder 3 - 165
Cylinder 4 - 165
Cylinder 5 - 181
Cylinder 6 - 190
that compression for that many miles is really good so i was a lot less worried. i then started to read around and see what common issues i couldve done. ive read about the crankshaft pulley and missing teeth, checked mine a million times and they are all still there, the belt washer thingy is there too. ive cleaned out the ocv filter from the banjo bolt and even put a new one in. i changed the ocv twice. first was a gates one then new oem. ive put a brand new oem vvti gear on also, still no change. ive read the coil connecter clips get old and broken and remembered one was broke so i put new clips and wires from what i could clip from the loom. all wires are soldered and thermal wrapped. all of these parts and nothing has changed.
i decided to drive around a bit and see if it would clear up. its a very very low idle about 100-200 and sounds like a motorcycle. has a very big hesitation starting when hitting the gas but once it passes 1500-600 something just clicks (not audible) and it just goes. seems to run fine but can tell theres major power loss and it would “redline” at 4500. the car wouldnt go past 4500 without sounding like 1000 screaming lawn mowers. the rpms also fluttered a lot while giving it gas. wasnt smooth increase. car sounded smooth going up but the guage kept going 3 steps forward and 2 steps back. i figured it might’ve been the IAC valve since that helps with idling and shuts off at 1500. i got a whole new throttle body (used from an is300 with 100k) since a new IAC is $300 and i got the throttle body for 100. throttle body made no change. while testing my radiator blew up so i put in a new denso one. cooling system is perfect. i realized my cat converters where glowing red after a short drive so i bought stainless headers and put them on. (since i figured it might be a bit to found out the issue i dont want a clogged cat being another problem). no change but the car is veryyyyyy loud since the bottom of the headers wont seat with the rest of the exhaust. i also heat wrapped the headers since i didnt use the og heat shield. i thought maybe a vacuum leak and changed all of the rubber hoses around the tb and intake plenum that was even somewhat tarnished. no change. i decided to go back to my brother at his mechanic shop and they told me to replace the ignitor module. i bought a new one from ebay which was oem and even came in oem packaging yet looked different than what i had on. i changed it and it ran more consistent. the rpms wasnt staggering and was smooth going up but not completely, once i hit 3500 it starts to stagger but a bit less. i thought maybe my intake with the air resonator being a common crack culprit. was very cracked on the bottom so i replaced with a makeshift one. theres a thread i followed on here that showed me. i took the sceptre pipe from oreillys and cut it and it fit perfectly. i also picked up maf cleaner and new air filter. still no change.
heres whats weird. i decided to change the serpentine belt cause it was old and there was a sale at autozone. i got a continental. i took the old belt off and thought of something. it ran nice when i had my bro come after i changed the belt. i started the car with no belt on and it idled perfect. i let it warm just until the coolant needle started to get in the readings. i put the new belt on and it went right back to “normal”, rough idle and sluggish. alternator also reads 14.5 volts
it is now 8 months later and ive put 10k miles on while its been running like this. ik ik its bad to do it but i haven’t had a “bad problem”. i need a car to get to work and this is all i have. it always cranks up and starts, no issue what so ever. doesnt get hot, no noises, no knocking nothing, ive always put in premium, never 87, and changed the oil every 3000, so 3 times. im truely stumped. sorry for the long explanation but i feel like the more details the better. i just got home from work and its 2 am so im going to bed. hopefully somebody sees this overnight. PLEASE PLEASE HELP
also i scanned the car last night and i got a p0011 and a p0016. those arent the only codes, obviously the misfire ones too. the filed attached is a video showing the low idle and the 1500k click. it clicks at 1000 cause its not in gear so not under load. its loud cause this is after the header changed.
05-11-23, 06:43 PM
#2
Just wanted you to know that we are listening and thinking. The only confusing thing is that it runs normal when you remove the. Accessory belt. I'm wondering if you dont have a bad Alternator? You would need an O Scope to see if your voltage is not stable. 🤔
Paul
Paul
05-11-23, 10:35 PM
#3
10th Gear
Thread Starter
the alternator seems alright it gives the right voltage when running and everything powers fine. ill see if i can find an O Scope to see what it gives back to me. Certainly the alternator couldnt be the only thing.
When i bought the car it ran beautifully no codes nothing, only when i did the belt change did it start, and i didnt go anywhere near the alternator during that process, strictly stuck to the front if of the motor.
also which way should the vvti gear be turned when installed pre timing belt? like should the slack be all the way to the right or left when matching with TDC? ive heard many people say opposites. Currently it is turned all the way to the left. must be right cause its been about 3k miles and everything still perfect in time.
05-11-23, 11:21 PM
#4
Lexus Fanatic
Did you do a compression test with the throttle plate propped open? If not your readings will not be reliable. Your compression readings are not "MINT" they should all be the same within a few PSI. Toyota doesn't mess around, their engines wear perfectly and maintain consistent cylinder/cylinder compression through the life of the car. Not counting any failure like head gasket, bent or burnt valves, major neglect etc. that kind of thing.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
05-12-23, 07:58 AM
#5
Did you do a compression test with the throttle plate propped open? If not your readings will not be reliable. Your compression readings are not "MINT" they should all be the same within a few PSI. Toyota doesn't mess around, their engines wear perfectly and maintain consistent cylinder/cylinder compression through the life of the car. Not counting any failure like head gasket, bent or burnt valves, major neglect etc. that kind of thing.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
Paul
05-12-23, 08:52 AM
#6
Instructor
VVT timing adjustments could be different between load and no load on the motor.
I believe the 2JZ has a waste spark ignition, with no load wrong ignition timing may be undetectable.
With no accessory belt there is no real load on the motor, I would put it in gear with the belt off to see if it craps out.
I heard the video, from my experience, it sounds like mechanical (cam) timing or ignition timing is not right.
Of coarse this is all just arm chair speculation, keep us informed.
Good luck
I believe the 2JZ has a waste spark ignition, with no load wrong ignition timing may be undetectable.
With no accessory belt there is no real load on the motor, I would put it in gear with the belt off to see if it craps out.
I heard the video, from my experience, it sounds like mechanical (cam) timing or ignition timing is not right.
Of coarse this is all just arm chair speculation, keep us informed.
Good luck
05-12-23, 01:48 PM
#7
10th Gear
Thread Starter
Did you do a compression test with the throttle plate propped open? If not your readings will not be reliable. Your compression readings are not "MINT" they should all be the same within a few PSI. Toyota doesn't mess around, their engines wear perfectly and maintain consistent cylinder/cylinder compression through the life of the car. Not counting any failure like head gasket, bent or burnt valves, major neglect etc. that kind of thing.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
Try putting an LED test light/bulb on the battery while the engine is running see if it flickers. Do you have access to an oscilloscope? One thing you haven't even considered is injector pulse. Bad ECU?
Engine sure sounds like the cam timing is wrong to me.
compression is very good, 190 is what comes from factory and the outer 4 cylinders are in line. ive read the inside cylinders will have less compression that the outside but idk if that much of a difference makes it bad. i was very careful to not touch ANYTHING other than timing related when doing belt. i never touched the injectors or anything. my brother had scanned the car and said all my injectors are running as they should.
i did the compression test with the throttle body off. when im accessing the plugs i always take off the throttle body right where it connects to the plenum. gas pedal was all the way down when i did the test so yes the throttle plate was technically open.
timing is dead on ill see if i can send a pic in a bit, so i dont think its the cam. i dont have an O Scope. and ive been thinking maybe the ecu, my lexus buddy has been saying it for a while. is there any way i can test the ecu to see if its bad or faulty?
i will test the battery as soon as i get a test light
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05-12-23, 02:00 PM
#8
Lexus Fanatic
Compression difference should be 14psi or less according to Toyota. Your compression is not "very good" the variation is too high and out of spec you need to find out why. That may not be the root of your problem but it is a problem.
05-12-23, 02:15 PM
#9
VVT timing adjustments could be different between load and no load on the motor.
I believe the 2JZ has a waste spark ignition, with no load wrong ignition timing may be undetectable.
With no accessory belt there is no real load on the motor, I would put it in gear with the belt off to see if it craps out.
I heard the video, from my experience, it sounds like mechanical (cam) timing or ignition timing is not right.
Of coarse this is all just arm chair speculation, keep us informed.
Good luck
I believe the 2JZ has a waste spark ignition, with no load wrong ignition timing may be undetectable.
With no accessory belt there is no real load on the motor, I would put it in gear with the belt off to see if it craps out.
I heard the video, from my experience, it sounds like mechanical (cam) timing or ignition timing is not right.
Of coarse this is all just arm chair speculation, keep us informed.
Good luck
Paul
05-12-23, 05:43 PM
#11
10th Gear
Thread Starter
the highest compression difference is quite literally 15 psi. i dont think that 1 psi would make a difference. plus its an old motor so it may go down and those are center cylinders. my head gasket is fine and i visually inspected the valves. they all seem fine
05-12-23, 05:44 PM
#12
10th Gear
Thread Starter
05-12-23, 05:44 PM
#13
10th Gear
Thread Starter
Here's a decent article on the VVT system.
https://carspecmn.com/toyota-and-lex...tle-2gr3gr4gr/
Paul
https://carspecmn.com/toyota-and-lex...tle-2gr3gr4gr/
Paul
05-12-23, 10:06 PM
#15
10th Gear
Thread Starter