Just put in a 1j in my brothers supra. The engine has been sitting well over a year before I got my hands on it. I wired it up and double checked and everything appears correct. The problem now. When trying to start it cold (unsure of when warm, only started about 5 times) it might catch immediately for a second and then die. Try and start it again and it will crank 10+ times easy before it might want to. If you start it and it starts trying to die and try to give it even the smallest amount of throttle then it will die. When trying to start it and you give it any throttle, again, it will not rev as easy during start up. I put a walbro pump and Denso Iridiums on it before ever attempting to start it the first time. It initially blew a couple caps and I replaced all of them which is still fine. Cleaned out my Idle Air Control Valve and never touched the TPS or anything else. I haven't checked the coil packs for cracks yet but was unsure if that would cause such crazy starting issues. When it warms up, you can rev it just fine and everything appears happy, idles just fine. Any ideas.
1j cold start issues
- Thread starter Alltoy4me
- Start date
tissimo;895100 said:
Yeah it has ran, its putted around for a total of about half an hour, multiple start and stops, because we were replacing all the brake components. Once it warms up its good. Just hard as hell to start. It was doing this even when the temperature outside was good.
I think it has something to do with the fact that when I am trying to start it and then give it a hair line of throttle, it sounds like the engine struggles more and will not allow it to start. If it does get to a hard idle and you touch the throttle at all, it dies immediately.
any codes? I had a supra with a broken water temp sensor that did the same thing, was hard to start when cold. after warm, it ran decent though.
tissimo;895317 said:
I've thought about replacing mine to see if it helps my cold starts. Anyone know of an alternate part no.?
THW is the ECU signal for temp. The temp sensor acts as a resistor between the signal and a ground. The resistance between THW and E2 is what the ECU sees as temp. 0=cold as fuck 
aphxero;895899 said:THW is the ECU signal for temp. The temp sensor acts as a resistor between the signal and a ground. The resistance between THW and E2 is what the ECU sees as temp. 0=cold as fuck
Huh. So if 0=cold as fuck then also hard as balls to start? It's hard for me to imagine that a temp sensor could do this, I mean if it went out on someone they would come close to draining the battery trying to start it from cold. I would love for it to be that easy.
Alltoy4me;896186 said:
People usually do. And it usually is simple for sudden efi probs. Open circuit in thw makes it a motherfucker. And if STA isn't hooked up it's usually worse depending on climate.
THW to E2 is closed (ie 0). Unplugged/broken is open circuit (ie hot as fuck)
Closed=more fuel for starting/warmup. Easier to start. Don't believe me go ahead and monitor it on warmup.
Ever tuned a standalone?
rakkasan;896926 said:
I was just asking because most tuners are used to looking at sensor logs and such. Nothing more than that
I had the same issue with my JZX90 1JZGTE the Green (Cold Start) sensor below the Grey water Temp sensor had gotten hit while I was changing the water pump. It was still hanging on but all of a sudden after getting the new pump in and starting it did not want to start so I checked the senor plug to see if they were tight and sure enough it broke off.
Thankfully Toyota uses the same cold start sensor in alot of thier cars so I used a celica sensor it works just fine. no more cold start issues. check that sensor for damage.
Thankfully Toyota uses the same cold start sensor in alot of thier cars so I used a celica sensor it works just fine. no more cold start issues. check that sensor for damage.