This is excellent advice and it actually works pretty darn good. Follow up with some Son of a Gun and a rag and it'll look just fine. Buy a bag 'o rags though cause you'll need it! Or I like to use the blue Shop Paper Towels for the greasy/dirty stuff with a degreaser like Simple Green, and then rags with Son of a Gun.

I guess my post came off a little harsh, just feel so strongly about guys washing their engines because I've seen it happen almost every time someone has done it.

As for the problem, there's just so many it could be, but start off with the basics; distributor/cap/wires/spark plugs and all wires going to/from these, then ignitor/coil connections, fuel injector connections, TPS, O2 sensor connections, and MAF sensor connections. Shouldn't take very long to unplug each one, blow it with wire drier followed by compressed air, and then plug 'em back in. If these things check out okay and it still has issues, report back!

 

So thank for all the advice guys, I took everything apart again cleaned all the connectors with compressed air cleaned all the o2 sensors and the distributor cap and wires. Checked all the injectors, checked all the sensors and everything seems to be okay. I put everything back together and it still has a slight misfire.

 

Is it a consistent misfire? If it is try this.

Some of the veterans on this board may have a problem with this, but its the old fashioned way to check consistent ignition misfire.

1)
start the misfiring motor.

2)
Pick which side you want to start from(back of the engine or front) and disconnect that first spark plug wire, then listen. If the engine sounds worse, put that spark plug wire back on and continue to the next wire in line and repeat the procedure.

If you end up removing a spark plug wire and nothing changes at all, then you have found the cylinder that is causing the misfire.

3a)
Next start with the easy things first, check over the spark plug wire and see if there any flaws with it. (To be honest, If you can get a new spark plug wire to use in its place to test that would be great. Because sometimes the flaws are internal and you cant see them until you slice the wire open)

OR


3b)
It could be the spark plug. So you would have to pull that out and check for signs of possible physical damage(missing electrode, missing some of the white ceramic, does it have an ashy white coat over the electrode or the ground[the metal hooked part of the plug]) Sometimes It doesn't hurt just to spend that 3$ for a new plug and see what happens.

4)
It could be your igniter that is now going bad. If this is the case, I feel confident in saying that if you cannot find your specific igniter # at your local junk yard, there are other toyota #'s that will suffice(usually other vehicles that run the same 2jzge you have).

For example when we used to swap out 5efe(1.5L) engines on the tercels and paseos and put in turbo starlet motors(4efte-1.3L), we could use the igniters with the number "201" on for both engines. That's one great thing I love about toyota/lexus.


5) Could also be your coil, but not likely.... darn near every time a coil goes bad it is does not work period. It is either 100% working or nothing at all.



Here are some extra questions:

-Does the misfire happen from instantly turning on the car, after "x" minutes of idle, or does it progressively get worse?

-Does temperature play a role on how bad it is?

-Does it idle fine, and then misfire under load?

-If you let the car sit at idle, pop the hood and rev the motor by pulling the throttle cable, will the misfire go away? If it does at what rpm does it stop misfiring?

 

Thanks for the advise kene, I had already tried removing each spark plug wire while the engine I running, and it doesn't make a difference, its hard to check cylinder 3 an 4 tho since it's rite under the manifold. But I did replace the spark plugs already, this is a second se of plugs I already replaced. When I start up the car, it misfires rite away, even when I rev the engine it misfires. The coil was already replaced, the igniter works perfectly fine, I check th relays and the fuel systems, seems to b fine. Once the car is warmed up, it idles at 500 rpm. I even removed all the 02 sensors and cleaned them and replaced one primary 02 sensor, usually when the vehicle runs rich, the 02 sensor will compensate and lean out the air/ fuel mixture. But it still has a slight misfire. So what else could it be?

 

did you pull any codes?

 

No check engine light on

 

Codes can still exist even without a check engine light.
Its happened to me a few times on my last obd I Toyota.

 

I checked for any stored codes today but nothing was stored, cel is not on

 

To check cylinders 3 and 4 , remove the spark plug wires from the distributor cap.

You mentioned you replaced the plugs....did you use any for of bosch platinum plugs?(I'm hoping not), If you used the bosch style platinum plugs(1,2 or even 4) that more than likely is the culprit. their electrodes are barely exposed. they work well on some european vehicles, but they don't translate well over to toyota/lexus(I can't say all cause I have not tried), and the old 89- early 90's jaguars(X-type?)


If you try cylinders 3 and 4 and nothing changes, then havea look at a new distributor cap.


better yet, can you video tape the misfire and put it on youtube?
maybe slowly rev the motor to higher rpm's and record the results?


that would help as well.

 

Check your TPS for water. My truck did the same thing.

 

@kene: the spark plugs that I used were NGK platinum plugs. I removed all the spark plug wires while the car is running and it still down not make a difference. I checked the distributor cap and found no problem, I even checked the resistance from the inside of the distributor cap to the end of every spark plug wire and everything seems to be within specs. So I checked all the sensors with a digital multimeter and found alot of resistance from the mass air flow sensor. So I'm guessing that my mass air flow sensor is faulty and it's not giving the ecu a correct reading so the engine is running rich and causing the car to misfire. So I will try to find known good mass air flow sensor and try that and see what it does.

@frk: I checked the TPS and cleaned it and it still had the same problem, thanks for the suggestion tho

 

Vacuum leak maybe?

 

I think I have a mass airflow sensor laying around..if not I will keep my eyes open at the junk yard.

 

I know this is an old thread. I have the same problem. what was the final resolution to this problem.

Thanks

 

Hello Lexus people,

my GS300 Ignition was changed and the car stated but missed timing

the engineer didnt get the timing right so i hear a sound (kra) whenever i do a sharp rev but when i do a normal rev (slowly) it doesn't make the noice.

note that I dont have anyone with timing light but i have volt metre.

please what are the side effect and the solution
can it knock my engine if drive to a distance place as it is now