1JZ wont go above 2000 RPM

[GN_Convert]

I did my 1JZ swap about a year and a half ago and everything has been going great until last week. It won't go above 2000 RPM. When it tries, it is like it hits fuel cut, as soon as it gets below 2000, everything is fine. I was getting codes for O2 and TPS, I replaced both, both faults are gone now. I checked the IDL voltage at pin 11 on the ECU, it is 0V at 0% throttle and goes up to almost 12 when the pedal is pushed. It idles like a champ, fuel pressure is 40 or so, I recently replaced my fuel pump and filter, so those are good. my Apexi AVC-R reads the throttle position and it is working fine. Ideas????? Please help, I miss my toy.

 

[GN_Convert]

Oh, and I replaced the caps in the ECU when I did the swap.

 

[kanji1jz]

Where you at in Florida?

 

[SupraSwampa]

Is it doing this when it rains? I have been experiencing some similar problem for about a month or so, maybe once a week. And it seems to only do it when it has rained recently. And it happened again about 10 minutes ago. Also it seems everytime this happens I've just filled up my gas tank.

Thanks, Jordan

 

[SupraSwampa]

Is it doing this when it rains? I have been experiencing some similar problem for about a month or so, maybe once a week. And it seems to only do it when it has rained recently. And it happened again about 10 minutes ago. Also it seems everytime this happens I've just filled up my gas tank.

Thanks, Jordan

 

[kanji1jz]

Might be something with the fuel pump in your case. Maybe it became detatched from the bracket and maybe floating upside down or something... I have seen this on customers cars in my shop, not necessarily Supras, but it could be a possibility

 

[z4ck]

Check your coil packs and make sure there are no cracks like this:

 

[dude4253]

+1 for coil packs
+1 for where in Florida are you

 

[AE86BLISS]

Have you checked all your cuplers for your intercooler piping? Maybe one is lose or came off?

 

[GN_Convert]

Melbourne.

 

[GN_Convert]

+1 for coil packs
+1 for where in Florida are you

Melbourne. I will pull the coil packs.

 

[Albert]

It's the crank positioning sensor

 

[GN_Convert]

Is it doing this when it rains? I have been experiencing some similar problem for about a month or so, maybe once a week. And it seems to only do it when it has rained recently. And it happened again about 10 minutes ago. Also it seems everytime this happens I've just filled up my gas tank.

Thanks, Jordan

I am in Florida, and it rains just about every afternoon this time of year. I drained my tank when I changed the fuel pump, so the gas is pretty fresh. It does it in the morning before it rains too.

 

[GN_Convert]

Have you checked all your cuplers for your intercooler piping? Maybe one is lose or came off?

All tight... thanks

 

[GN_Convert]

It's the crank positioning sensor

Shouldn't that cause a code to show? Is there a way to check short of replacement?

 

[GN_Convert]

Check your coil packs and make sure there are no cracks like this: View attachment 60442

#3 coil pack has a little crack underneath the rubber boot. after I pulled them all and reinstalled them, it went to 7500 once. Since then, it has been limited to 2000. If I go full throttle, or creep up on 2000, it shuts off at the same point. I'll see if I can find a coil pack locally, if not, I'll order one and try again.

 

[SupraSwampa]

Check the Idle Air Control valve. I changed my O2 sensor back to my old one and it fixed my problem with the car running extremely rich, and I thought it fixed my reving problem, but I drove it about 12 miles to work this morning and pulling in the parking lot it started reving at random RPMs again. I know that my IAC is going out and I think the ECU might be taking a dump too. But between the two of them it's very confusing.

 

[GN_Convert]

OK, so I have not replaced my coil packs yet, but I did put some heat shrink around the two that had cracks. It made no difference. If it sits for a day, I can start it up and it will rev normally for a few minutes, then it is back to the 2000 cap. Still no codes. I know I need to replace the two coil packs, but I want to be sure $160 for both of them will fix the problem.

 

[GN_Convert]

I got the new coil packs in, it is doing the same thing still. There are no fault codes. When I first start it, I can take it up past 2000, but after a little bit (20-30 seconds), it keeps shutting off at 2000. My wideband and AVC-R both show the injectors shut off, so it is like it is hitting fuel cut. I replaced the ECU capacitors when I did the engine swap.
Any ideas????

 

[shipkiller]

Crank position or cam position sensors