2JZSoarer

Ok, I know this should be a rare problem; but if anyone of you guys have experience this or have an idea about this, please suggest something.

My NA 2jz is not running correctly to say the least. In trying to fix the problem over the weekend, I replaced the MAF senor b/c if I unplug the senor, and the engine did NOT choke in any way and actually still allowed me to run around town. So, my theory is she's running a factory safe map instead of reading and adjusting to MAF accordingly. So, I bought a 1st gen GS300 MAF senor and bolted it up. With the plug unplugged, she choked at a lower idle as i expected; plugged it back up, choking is gone. BUT I'm still not running correctly. She literally sounds like a Subaru with the pulsing of the exhaust note, even under load going through gears sounds like a Subaru.

So, another experiment was conducted. I individually unplugged each coil wire from the distributor. I was looking for the one that does not choke the engine off. I went through all of them, and number six cylinder did not react to this experimentation. As the plug for the #6 cylinder is unplugged from the distributor, the engine just kept the abnormal running condition. So, my theory is even #6 is firing from the distributor, but there isn't spark in the combustion camber. So, my next step is going to check my plugs and perhaps a compression test.


So, does anyone have experienced this or any an idea what might be causing the problem?

Thanks a LOT!!
Kenny

CCC-TT

iTrader: (1)

no idea what the problem is but it sounds like your going about diagnosing it well. Does the car throw any codes?

2JZSoarer

no code on dash...

5sp_jzz30

iTrader: (2)

i had exactly the same problem and even the MAF issue where it would run and drive without it plugged in.

my problem was that i let my friend drive it at a drift day and my valve cover gaskets melted from the heat and flooded the valley where the spark plugs go. this oil caused the cyl. 5 and 6 to not have spark. so i was driving home 240 miles away on 4 cylinders. a guy in a wrx on the high way even gave me a WFT? look when he drove by lol.

i doubt you have the same issues as i did. i took apart the whole top end and replaced the valve cover gaskets and plugs and put it back together. after that it runs normal.

in your case you might have a bad contact in a distributor cap or a spark plug wire problem. i would have the engine running and pull of each spark plug wire off the distributor to see which one makes it run worse and which wire doesnt make a difference. if you pull a wire and the car keeps running the way it did and doesnt arc to the chassis then you have a wire problem.

keep us updated and PM me if you need any more help.

DRFTSC400

iTrader: (1)

Looks to me like you're car is misfiring. it does like sputtering sound right? Check your compression, timing, distributor cap.

2JZSoarer

thank you, after all those views, someone finally post and suggest.

Well, I just ordered plugs and wires. I plan to put those in along with distributor cap and rotor. So, that's basically all the ignition components there are.

5sp_jzz30, since you brought your case up with drifting. My car did undergo some drifting in the past 6 months. I also autocross it too. So.....hmmm..

I do know it's #6 cylinder since I unplugged #6 coil from distributor; and it still act the same. All the other 5 kind of choked it a little.

5sp_jzz30

iTrader: (2)

its usually cyl 5 and 6 because the motor is not perfectly level in the engine bay. it leans back slightly. any oil that may escape goes to the back of the motor.

what happened to me is my friend was "practicing" doing the "figure 8" at the skid pad....in first gear at redline...for 20 mins. lol. the motor got so heat soaked the valve cover gaskets started to melt and leaked oil from the top end into the spark plug valley.

my car has been drifted for 2 season with no issues. this arises from lack of air circulation and very high oil temps in the motor. if you are going to be doing a lot of drifting then get an oil cooler setup and power steering cooler as well. best bet would be to buy/ find at a junk yard an oil cooler from an FC late 80's RX-7. those coolers are huge.

that is my next project before next season starts along with a master cylinder stopped.

keep us updated.

btw check your maf. it might not be bad. get a DMM and follow FSM to diagnose it.

2JZSoarer

ok, just for update and for goods of CL if anyone has this problem.

I started to change my plugs this weekend; I was going through the usual mess all of us NA 2jz have to go through...
First cylinder plug, clean. But I went ahead and change it out since I wanted to run #5 plug instead of #6 (temp. rating if you have to ask). I also changed the wire to narrow down the possibility.
Second cylinder plug, clean. Change it to new plug along with new wire.
Third cylinder plug. WET!!!!!!!! It's even a little drippy with oil !!!!!
I just went ahead and pause the changing process and just pull my #4th, 5th, and 6th cylinder's boot to see the condition. All of which were soaked with oil.......
So, here's what I have this weekend. First and second cylinders are dry and health looking. Third, forth, fifth, and sixth are all wet. So, I have no clue how many cylinders were actually able to have sparks.

So, I had to decide what I should do.
(1) Open my valve cover and change gaskets for the spark plugs valley (which I was told by Advance Auto Parts that there is no such gasket) and change valve cover gasket of course. And pray that is the only problem.

(2) Pull the engine out and refresh EVERYTHING and throw some more stuff in to make me quicker in autox but still keep me in the same class

(3) NA-T

(4) 1jz

I think I'm going to go with (1) b/c it's the most economical way for the situation I'm in. So..there you have it!

Collan

mine was doing that too, I couldn't figure it out, so I took it to the shop and they said my #5 and #6 spark plug wires are arcing to my valve cover. I think getting some nology wires will fix the problem.

2JZSoarer

Ok, I'm back with more details to my problem to contribute information to CL. (Clift Notes are at the very bottom of this post)

I changed out my valve cover gaskets (intake and exhaust are separated by the spark plug valley; and also no gasket/gourmet for spark plugs), six new spark plugs, new wires, distributor cap and rotor. Everything were back in place. I cranked the car up to see what happens...

She cranked right up; and sounded healthy (sounds normal with all 6 cylinders). I also revved it up to make sure it was all 6 cylinders were working. So...no EJ20 sound.

So then I clean up the garage area and wash up for a test drive. I cranked her up and the problem came back (not all 6 cylinders were working properly).

Well, I made sure all 6 cylinders have spark by checking the coils on the distributor with the motor on. All 6 were fine. I pulled #1, #5, and #6 cylinders' spark plugs. It appeared to me that #6 didn't get any combustion; it only collected the carbon from #5 cylinder.

So I checked the voltages on my injector clips. As I primed the fuel system, #1 cylinder received 5V at the injector clip for a second then back to 0V (normal). Then I went to #6 cylinder's injector clip; same thing for a second then back to 0V. So I cranked her up.

#1 cylinder injector gets about 12V to 13V as the car idles. #6 cylinder injector was not getting any voltage at all.

So I came to a hypothesis that my ECU isn't sending signal/voltage to #6 injector for fuel/combustion. Now, it could be more than just #6 since I didn't test #2, #3, #4, and #5's injectors. So I need to test if my ECU is bad or is it something else? Can anyone let me borrow their non-vvti 2jzge's ECU? I'm in SE GA.


Clift note: no fuel going to #6 cylinder. Possibly a faulty ECU. In need of a favor to test another ECU to see if that's a solution before purchasing an ECU of my own.

Thank you,

Kenny

wanganstyl

iTrader: (5)

actually, check if you are getting power on ign+ mode- all the injectors are powered via the EFi+ circut- black with orange wire stripe. the ECU directly connects to the injectors on the ground side- the ecu grounds out the constantly powered (when key is in ign+) injectors to fire them.

check your injectors individually- black wire should have 12v+ when key is in +, the other wire will have signal being grounded by ecu when you crank the ignition. you could have a physically broken wire if you did have #6 running but somehow lost it- the wire could be broken on the power or ground side