Rough idle & acceleration. Codes 24, 34, 42 & 52...

[Suprapowaz!(2)]

Recently I've been having an intermittent rough idle on cold starts. It would go away within seconds and run smooth. Now the problem is constant. Check engine light came on and gave me codes of 24, 34, 42 & 52. I did find the KS (afm) wire broke off of a crimp I did when I wired in the MAPECU. I wound those up together, cleared the ECU, and rechecked for codes just to get the same ones.
I was about to tear into all the wiring and check for continuity, rewire my rewired knock sensor again and the whole bit.
Today I stopped by a friends shop to borrow his leak down tester. Performed the test and cylinder #1 had 100% leakage!! Air was blowing past the intake valve cause I heard and felt it come from the throttle body. I quickly checked #6 because it was also at tdc on the compression stroke. 100% leakage in that one blowing past the intake valve, too. Timing belt must have jumped. I couldn't confirm this tonight because I was taking the family out for dinner and didn't want to get my hands too dirty.
I'll be getting into this the next coming days to keep you guys informed.

This is why it is important to do a LEAK DOWN TEST. I was going to be chasing my tail with troubleshooting all electrical sensors, harness, and ECU. I still might have an electrical issue, but I sure as hell have a mechanical one.
This is why I preach leak down test. It really should be the first thing down when having problems. Everybody having "rough" running problems need to do a leak down test.

I will add I run probably the cheapest, shittiest timing belt out there. It was new that I bought from another member that decided not to run it because he knew it probably wouldn't last. Go ahead guys, fire away.

 

[super51fan]

Are you sure you know how to use a leak down tester? I

 

[Suprapowaz!(2)]

Yes.

 

[super51fan]

Not trying to be a "ahole". I find it confusing how #1 and #6 could both be on compression stroke at the same time? Plus I cannot see how these codes could be caused by 100% leak down. I do wish you luck with your problems.

 

[jetjock]

^ You're not the only one...

 

[Suprapowaz!(2)]

Not trying to be a "ahole". I find it confusing how #1 and #6 could both be on compression stroke at the same time? Plus I cannot see how these codes could be caused by 100% leak down. I do wish you luck with your problems.

Is why I stated I still may have an electrical issue. I'll find out in the next coming days.
I could be wrong about them both being on the compression stroke, but they are both tdc. Don't both of those cylinders have all of their valves fully closed at the same time when they're both tdc?


EDIT: I'm completely wrong on my way of thinking how this 7m works. You're right... none of the cylinders are ever both on the compression stroke at the same time. I also found out that even though they're both at tdc their valves are not fully seated at the same time. More on that later I'm at work.

 

[super51fan]

It is best to pull cam covers to verify valves are closed. I would still fix TCCS faults first. Good luck. Sorry you are have problems.



Heck since you already have tool go ahead and do leak down test.

 

[IndigoMKII]

EDIT: I'm completely wrong on my way of thinking how this 7m works. You're right... none of the cylinders are ever both on the compression stroke at the same time. I also found out that even though they're both at tdc their valves are not fully seated at the same time. More on that later I'm at work.

So glad you corrected yourself.


Also, don't check the cylinder while it's just at TDC, check it on the top of the power stroke so you know for sure both valves are seated.

 

[Suprapowaz!(2)]

It is best to pull cam covers to verify valves are closed. I would still fix TCCS faults first. Good luck. Sorry you are have problems.
Heck since you already have tool go ahead and do leak down test.

Yeah, I've been grabbing at straws to find out what's going on with the car. I need to take a step back, clear my head, read a damn manual (tsrm), and get to it. All of this assuming how shit works, and trying hard to find the culprit is making me do stupid stuff. I do need to fix my electrical stuff first.

 

[hvyman]

7m is non interferrance meaning valve could be all the way open at tdc and nothing will hit. No1 will be at tdc compression while no 6 will be at end of exhaust stroke and Begining of intake stroke so both intake and exhaust valves could be slightly open.

24 is afm and 34 is boost leak. I'd start by checking for boost leaks.

 

[Suprapowaz!(2)]

UPDATE: All codes are cleared. You guys remember that KS (afm) wire that broke off the crimp that if temporarily fixed to see if my codes would clear? That's what it was. The main problem was *gulp* me. I thought I was clearing codes by pulling the main fuse for a few seconds, but it was the main relay I was pulling. That doesn't clear codes from the ecu. :nono:
I pulled the positive terminal from the battery off for a bit and reconnected it. Jumped T1 & E1 to read the codes. Continuous rapid blinking is what I got meaning no codes. So that part is good.
This morning before I headed off to work I did a quickie leak down test, this time with the cylinders actually on the compression stroke tdc, and I was getting readings. I don't have 100% leakage. I was not in the compression stroke the last time I did the test. Doing stupid shit again.
Now I have to put my car back together, and see if it runs smooth with no hesitation or hiccups.



I like to thank my friend Miguel for walking me through my steps, and helping me realize I wasn't clearing the codes properly. Thank all of you guys for putting up with my stupidity. I'll keep you guys posted.

 

[1988ma70supra]

UPDATE: All codes are cleared. You guys remember that KS (afm) wire that broke off the crimp that if temporarily fixed to see if my codes would clear? That's what it was. The main problem was *gulp* me. I thought I was clearing codes by pulling the main fuse for a few seconds, but it was the main relay I was pulling. That doesn't clear codes from the ecu. :nono:
I pulled the positive terminal from the battery off for a bit and reconnected it. Jumped T1 & E1 to read the codes. Continuous rapid blinking is what I got meaning no codes. So that part is good.
This morning before I headed off to work I did a quickie leak down test, this time with the cylinders actually on the compression stroke tdc, and I was getting readings. I don't have 100% leakage. I was not in the compression stroke the last time I did the test. Doing stupid shit again.
Now I have to put my car back together, and see if it runs smooth with no hesitation or hiccups.



I like to thank my friend Miguel for walking me through my steps, and helping me realize I wasn't clearing the codes properly. Thank all of you guys for putting up with my stupidity. I'll keep you guys posted.

Don't sweat it bud, everyone has one of those moments::dt-blonde::. I'm just glad i was able to help you get on the right track

 

[7M4EVR]

7m is non interferrance meaning valve could be all the way open at tdc and nothing will hit. No1 will be at tdc compression while no 6 will be at end of exhaust stroke and Begining of intake stroke so both intake and exhaust valves could be slightly open.

24 is afm and 34 is boost leak. I'd start by checking for boost leaks.

Is code 34 actually a boost leak or is it fuel cut as well?. My boost spiked to about 15psi today (turned boost controller wrong way) and when i got on it the car lost power for a split second and CEL came on and went away after bout 10 sec. Pulled codes and had 34 after that. Im curious because i just did a boost leak test up to 30psi and didnt hear anything. And its been a while since ive experienced fuel cut but i remember it being more noticeable than what happened today....i guess the new piping kit is coming sooner than i thought

 

[IndigoMKII]

34 is fuel cut. Fuel cut on 7ms normally happen when either a boost leak is present or as you found out, a wrongly setup boost controller.

Look at the description of code 34 "Abnormal boost pressure"

 

[7M4EVR]

34 is fuel cut. Fuel cut on 7ms normally happen when either a boost leak is present or as you found out, a wrongly setup boost controller.

Look at the description of code 34 "Abnormal boost pressure"

Well i just thought it was weird that I'm hitting fuel cut at 15psi with my mods (lex/550). Hopefully, when I get new piping and upgrade to the DM 11psi wasegate that will help. I won't be happy forever at 15psi on a 60-1.

 

[hvyman]

Getting those are not going to raise fuel cut. When you outflow the stock afm you hit fuel cut. Either get at a lexus afm or go standalone.

 

[7M4EVR]

I have lexus afm/RC 550's, afpr, fmic, and and safc but the safc is not hooked up yet. I thought for sure id be good past 15psi with that. Wondering if the tune has anything to do with it? I will know more once i get my wideband back on there and get the new piping. Then i will be ready to (purposely ) run around 15 psi.

 

[IndigoMKII]

play with the air bypass screw, it'll lean you out though.

 

[7M4EVR]

play with the air bypass screw, it'll lean you out though.

thanks...i'll play around with that when I get the WB back on. I used a portable to tune and where i have the AFM screw set was where my AFR's were good so i don't want to play with that until I know what's going on. But when I was tuning it the first time all the way in vs. all the way out didnt make much of a difference in AFRs (maybe .02-.04). But by opening it up all the way and then adding fuel with the afpr to compensate it should in theory give me a couple more PSI to work with ehh?

 

[IndigoMKII]

by playing with the afm screw and the afpr, you might be able to keep the vF happy.