myLEXsc400

My car still has codes that pop up after a bit of driving for a misfire on every cylinder, and a code for exhaust gas recirculation flow excessive. Is it possible the EGR is leaking and causing the misfire? I l cleared the codes a couple days ago to see if changing the MAF to a newer one makes a difference (it didn't), and this morning when the CEL came back on, it started flashing. Its never flashed before. The car drove like it was really struggling to move with every gear change. I have no idea what this might me. No new codes except misfires and EGR

On a side note, I went to get the car emissions tested, and it got rejected because not everything showed ready when the plugged it into OBDII

Ali SC3

iTrader: (10)

yeah as I said in the other thread there are a few places the egr pipe can leak and since its connected to the intake manifold any leak before the EGR will create a vacuum leak which can cause misfires like that and any leak after the EGR where it connects to the lower runner will cause an exhaust leak cause thats where the exhaust gases come out for the EGR. an exhaust leak there will cause driveability issues I have had that one several times cause its a hard area to reach, it can throw off the o2, the egr, and mess with the boost.
any kind of vacuum leak is going to throw off what the maf and ecu are seeing. check the whoel metal pipe for the EGR from where it connects to the Y pipe on the intake all the way down to the flange on the lower runner.
Definately check the big nut on there to make sure its tight and that all the vacuum lines are going to the right places. if the EGR is hooked up wrong and opening at the wrong time funny things can happen also.

the exhaust leak on the lower runner is easy to find as I said just stick your hand down there on the first start of the day when everything is cold and if you have a leak its easy to feel the hot exhaust pulses on your hand. for the vac leaks by the intake well those you can't feel by hand but they are much easier to reach so just make sure they are tight and have the gaskets in there.

187

Well I got the same random missfires today every cylinder ect, Set my idle back down but i can hear the missing when i hold 2000rpm. I can't tell if its spark or the throttle, but I'm getting way to much fuel on the rev down to idle a solid 10.

What kind of gap are you running?

myLEXsc400

ok, so there is definitely something with the egr that i need to fix, but i have a feeling that the misfire is independent of the egr. my car misfires audibly at idle, and when you drive it, you can tell something is a little off. is it possible some of this issue may be due to a faulty MAP sensor? I'm running a MAP from a 1jzgte motor. should i get one from a 2JZGTE? Is there a difference between usdm obdi and obdii MAP sensors?

Ali SC3

iTrader: (10)

the 1jz and 2jz map sensors should be the same, but it is possible to have a faulty one. I don't think it will affect how it runs though on a USDM ecu it is used for timing the twint turbo vsv's and boost cut not how it runs.

myLEXsc400

aha, so there is basically no reason to replace mine then?

Ali SC3

iTrader: (10)

I wouldn't think so. at this point I would check the coilpacks/plug wires/ and pull a plug to verify correct gap. you can pull the number 1 and 2 plug pretty easily just remove the timing cover, that should give you a good idea of the plugs without having to take the whole intake off.

what plug wires did you use for the coils? try and take a look at them at night with the motor running sometimes the stock wires get pinched or go bad and you might see the spark jumping in the dark.
also take the boots off the coils and check for cracks on the coil plastic. can cause misfires.
I used new NGK wires so I never had any of those issues.

I would rule out the maf so far since you have tried 2 of them and both the same.
and when you reset the ecu pull the battery cable, don't just clear via the scan tool.
sometimes the system needs a good old fashioned reset.

I think it could be ignition related, a bad ecu, or a leaky fuel injector/fuel system issue.
I would lean towards an ignition issue but you will have to check each system individually.

I did just read on the ES350 forum that its very common when you get 1 bad coil to have all 6 cylinder misfire codes come up.
This jives with all the other reading I am seeing on random misfires, its usually the coils, so I am going to go out on a limb and say at least one of your used coils is acting up.
may want to get a new coil or another set and mark them and start swapping them out till you find a working set.
Buff said he got rid of his misfires by using new coils, so I think this could really explain it where did you get the coils from?
This is a pretty straight forward fix so its worth checking this first I think this is your issue so many people on MY.IS have replaced all the coils due to misfires its probably not a coincidence.

url]https://www.clublexus.com/forums/es350-2007-2012/525786-ignition-coil-malfunction-misfire-in-all-6-cylinders.html[/url]

187

Idk i got the same codes and I don't even have coils. I'm about to go nuts tomorrow since I have off and post my findings back in the original thread.

When I got misfires it was because the throttle was to far open at idle and it was freaking out even though the day before It was set similarly a ran perfect as far as i could tell. It's seems as though the ecu is hyper sensitive.

myLEXsc400

So I was speaking with a local mechanic yesterday, and we got on the topic of my car misfiring, and not being able to pinpoint why, and after telling him everything I did to it, he says he's 99% sure it has something to do with the cams, and cam timing. Is it possible that might be why? I tried running the car off GM coils a couple days ago just to see if it makes a difference, and the car still misfired on every cylinder.

Vrank

iTrader: (4)

I highly doubt you have an issue with the cams. You can't **** up cam timing unless you skip the belt or played with adjustable gears. So if neither of those happened, that theory is well out the window and your mechanic should be too as he doesn't understand how this engine and management system work.

All you guys have been focusing on is ignition. You also need fuel and compression for a firing event. I've seen faulty injectors create random misfires. Food for thought.

Does anyone actually know how the obd2 gte ecu detects misfires? I know for the ge, they added a supplemental trigger wheel at the crank that is the same one used for the vvti engines due to a broader range of resolution which is how the ecu pinpoints which cylinder is misfiring. I figured this out when I rectified a random misfire on a 1/120 car by replacing the trigger wheel due to some back who didn't know there was a retainer for the trigger wheel and snapped a tooth of. That one tooth missing gave cyl 1 and 6 random misfire.

The flashing cel is a warning that the cat may be in danger due to unburnt fuel entering based on misfire events.

Ali SC3

iTrader: (10)

the gte obd2 ecu doesn't have the more defined trigger wheel, its got the same one as the obd1 gte, so it doesn't have that super accurate wheel for misfire detection. How it does it exactly is a good question, I would assume like most of the toyota ecu's it has a window of time where it detects it and its probably going off the stock 12-1 trigger wheel which is not as accurate.

maybe its detection is so accurate it does not like the distributor 12-1 signal as much as the crank 12-1 signal. since obd2 ge has that extra trigger wheel setup, one would not need to swap out the oil pump but could just swap the GTE 12-1 trigger wheel on there and also swap the wires at the ecu to make the crank run off the crank just like the gte setup instead of the distributor, it would be the exact same thing then and the distributor one would just be left unplugged. that would be wierd if that was the problem but as Vrank pointed out its probably how it detects misfires is variances in the crank signal. I think missing IGF brings up a different code but maybe could also trigger it, will see if I can find some literature on it.
I would also recommend for the time being unplugging your second crank sensor on the oil pump while it has the 96+ timing gear on there. its possible this could be creating some additional noise via the shared ground, I would just unplug it at the connector by the alternator for good measure and see if the misfires trip any less.

if its not injectors like Vrank mentioned which we knew was a possibility but skipped over since they have been re-flowed and tested, then it could also be that the tune is just too aggressive and in certain lower loads its not combusting reliably, i would guess when its in closed loop and leaned out to 14.7 it is maybe struggling with extra timing. did you set your base timing to 8 degrees with the car warmed up? I forget did you do the tt headgasket? I was reading that some mk4 tt's have fueling issues due to the tps on obd2 as well which would rule out timing. those ecu's are just very sensitive.

how did you pass emissions before, clearly you weren't getting misfires then or it wouldn't have shown ready.

edit looks like Vrank was onto something, from the obd2 97 supra 2jzgte manual, uses cam and crank for misfire detection.
from here http://www.97supraturbo.com/1997%20S...ics-Engine.pdf

ScBouncE

Was this issue ever resolved? I am concerned with passing emissions (NJ) as well so I'm going to probably end up using this same ECU but would like to see more info on this topic.

Ali SC3

iTrader: (10)

I can't remember who it was but one person it turned out to be an issue with the injectors. still would like to hear the end results from more of the obd2 swappers and get some resolution to this whole misfire thing.

187

My obd2 tt ecu mod passes nys inspection but I don't have emmisions. There is a bit of extra work but thats what you get with obd2. You can kind of follow my posts in the tt ecu thread to see what happened or pm me for more specific stuff.