1jz idles but will not rev

[kanji1jz]

We only removed connectors that were just sitting in the engine bay not plugged into anything. The diagnostics check connector was just one of those that was sitting there not doing anything.

When things like this are said in serious conversation I tend to believe that the person doing the work should stop doing whatever it is that they think is logical and take it to a reputable shop if they want their car to run properly again without any issues. I thought I had heard it all... NOW I have.

 

[Dylan JZ]

Too many potential problems..

GL.

 

[IBoughtASupra]

Get a different harness. Adapt it to stock. Don't remove anything. Problem solved.

 

[kas14slider]

When things like this are said in serious conversation I tend to believe that the person doing the work should stop doing whatever it is that they think is logical and take it to a reputable shop if they want their car to run properly again without any issues. I thought I had heard it all... NOW I have.

Ok, so explain to me how removing an oem diagnostics connector that I will clearly never ever have any use for is a bad thing. Its not rocket science. The car runs perfectly and has a shitload of electrical connectors in the harness that aren't plugged into anything. So clearly, those are not needed for the car to run. You make it sound like we just removed random shit. If you look at the list of everything we removed it seems like you don't need any of that for the car to run. Now where we did mess up is in the actual shortening of the wires. It seems to me that crimped connections are not the way to go. I just wanted to verify this from someone who actually does a lot of wiring and see what they had to say.

 

[kas14slider]

And I am searching for a harness. And when I find another one, I will still remove all the not needed wires. I just won't have all the other wires shortened

 

[Dylan JZ]

You could always contact Dr. Tweak and ask him if he has any advice after providing him with the details.. If not, there are two options (IMO): send your current harness or lack thereof to him and have it repaired, or you can buy another harness and send it to him to do the removing and any other modification.

If you repeat the original process, there's a rather high probability of this occurring again. Why? Well, what evidence shows that the shortening of the wires is the sole problem? There are many possible issues here that are not mutually exclusive.

 

[kas14slider]

Yeah, I heard of Dr Tweak before. Does he have a website or do you know his contact info? And I figure it has to be the shortening of the harness because the car ran perfectly before we messed with the harness and we components that were not being used at all and shortened all the other stuff. And the car turns on and idles fine and even revs good when you first start it up. So I think as the car warms up, some of the wire's resistances could be changing due to our crappy crimp connectors.

 

[kas14slider]

Also, I was offered a jzx90 harness. Can anyone confirm that jzx90 harnesses/jzz30 harnesses and ecu's are interchangeable? From what I can google they are but I'm not 100% sure.

 

[kas14slider]

Nevermind, found Dr Tweaks website, will give him a call monday

 

[Radial]

You said in your first post that pins where bendt, what pins where bendt? Perhaps the O2 pins or something?

Irdium and Platina-plugs does also not handle poor coldstarts etz and easily gets defective (Short to ground because of Carbon build-up)...as you where struggeling with the bad pins in the start, plugs get clogged by the exessive fuel.. and I think thats the source for your problem. Just replacing them with BKR6E's is also a cheap fix.... if they get clogged, its just to clean them with some sandpaper. Platina just destroys itself when rubbed with sandpaper.... but it lasts long when treated right..

Thats my opinion though

 

[kas14slider]

Well, I use BKR7E's. I have put 5 sets of brand new plugs in it after all the times it ran rich for a while. I guess it can't hurt to throw another set in there. Also, a random question. Does the ecu need the knock sensors to be plugged in to be happy. Because from what I understand, knock sensors only come into play when knock is actually detected and it grounds the knock sensor wire.

 

[kanji1jz]

Ok, so explain to me how removing an oem diagnostics connector that I will clearly never ever have any use for is a bad thing. Its not rocket science. The car runs perfectly and has a shitload of electrical connectors in the harness that aren't plugged into anything. So clearly, those are not needed for the car to run. You make it sound like we just removed random shit. If you look at the list of everything we removed it seems like you don't need any of that for the car to run. Now where we did mess up is in the actual shortening of the wires. It seems to me that crimped connections are not the way to go. I just wanted to verify this from someone who actually does a lot of wiring and see what they had to say.

Unfortunately you are stubborn judging by the post after this one stating that you will be doing the same thing that you just did. So, basically, there is no getting through to you the need for this connector or any of the other ones. Maybe it's not the shortened wires. Maybe it's something that could be easily discovered if you had the diag connector and a CEL hooked up. Maybe you deleted one too many important wires/ connectors that you "think" aren't useful. Maybe it's nothing that you have done, but something that has failed in the interim. I mean, if this was the proper way to remove wires and redo your wiring harness wouldn't it have worked the first time? I have removed plenty of wires from my harnesses over the years. No major issues... Then again I am a certified tech with a lot of automotive experience about knowing what to keep and what to discard. Good luck, this isn't gonna be a cheap/ quick fix.

 

[Radial]

Well, I use BKR7E's. I have put 5 sets of brand new plugs in it after all the times it ran rich for a while. I guess it can't hurt to throw another set in there. Also, a random question. Does the ecu need the knock sensors to be plugged in to be happy. Because from what I understand, knock sensors only come into play when knock is actually detected and it grounds the knock sensor wire.

I think I rememer that it needs the Knock-sensor "Loop". Its actually more vital than you think..

Just clean the BKR7's then.... probably lots of carbon there.

 

[tErbo b00st]

You don't need the knock sensors. I have been running without my rear sensor for several years. Crimp connectors are most likely not your problem. you said it runs good until it warms up, did you check the resistance of the coolant temp sensor?

Are you 100% sure all of the pins on the ECU connectors are good to go? Maybe you missed one?

Did you do ANYTHING else, even change the oil, while you were doing this wire cleanup? Don't stay too close minded that it is because you shortened some wires. Maybe you were changing the oil and knocked a sensor loose? I know I have had a couple situations when doing various work on my car that a wire pulled out from the sensor from age. Make sure all the wires are pinned into it's connector properly. Maybe you adjusted the idle control valve or throttle stop and didn't adjust the TPS properly? I'm not asking you to confirm any of these, just think about ANYTHING you did to the engine besides shorten and remove wires.

I would highly suggest going over the harness and verifying vs the OEM wire diagram with a voltmeter. The fact that your friend completely changed the power source for ignition and fuel tells me that he made some really poor decisions when rewiring. Is every single ground wire that was on the harness before, still there? Have you verified all of the grounds are going to where they should on the chassis/engine?

What is the gap on your plugs?