Intermittent miss up to 2k and idle when warm NA-T

[pwpanas]

Apologies for the delayed response...and thank you for posting your question.

To begin with, please note that I'm much more familiar with the 2jz-gte...so you may take my advice with a grain of salt.

Here goes:

Originally Posted by Travis89Turbo

Hey guys. Having a small issue with my Na-T on my 70k miles 2jzge I am running the 4 runner cap on stock dist. To clear turbo. Although still touching intake pipe...

Just offhand, this doesn't seem like a great idea. Is there any way you could re-route the intake pipe to completely clear the distributor? Also, is the 4 runner cap a standard solution for an na-T Mkiv?

Originally Posted by Travis89Turbo

...Car idles and runs amazing until it gets a little below mid operating temp then it starts to stumble on idle goin to almost 16 on afr. And I loose vac. Down to about 10. Sometimes if I shut it off and start back up it goes away until I warm it up again. It stumbles and hesitates up to about 2k rpm. Never had this problem before the NA-t I haven't really boosted until I get this sorted New cap, New 2j rotor new wires. Will be pulling plugs today. Gone through all connections. No vac leaks, have sprayed everyone. Help me I'm stumped. I have inspected the Bov, and wastegate diaphragms which are in good shape.

Edit..... Car is 95 Supra SE. 70k miles. Stock HG, stock fuel system. New o2 sensors. There is no Check engine light or codes.

Update. I took it for a ride at lunch. This time it started missing and stumbling before even 1/4 to temp. I have no idea what is goin on. I did find that my O2 sensor plug was melted but it is and was still making contact. Any ideas at all. Also I sprayed again every vac Lin and intercooler line with starting fluid including the throttle body. No leaks found at all. I'm lost. Please help

Pretty sure this problem is with my Ignition system. I did have to order a set of spark plug wires so i could run the 4runner cap, i needed #2 wire in the #1 spot for length. While it was idling yesterday i pushed on the plug wire at the dist. and BOOM shocked the hell out of me. I changed it to another one from the "new" kit and it seems to be running better but still intermitenttly will miss and stumble but not near as much. Does any one have ideas??

Okay. Its not the ignition system. I built some MSD wires for it another new cap and rotor from Toyota this time problem with missing got worse and afr are even leaner now. So I went to the fuel system, I unhooked the vac line off the fuel regulator and capped it and it smoothed out a bit but still in the 15s instead of 16.5 on the afr. It also does not take long at all for this to start happening so the problem is getting worse So I am ordering a fuel pump. :crazy2

Is your Supra an Mkiv? If not, this question may be in the wrong section...

What spark plugs are you using? How long have the spark plugs been installed?

Fwiw, I don't think it's the fuel pump. You should check the fuel pressure before replacing the fuel pump. If anything, replace the fuel *filter* first.

That's it off the top of my head, for starters. Please let me know your thoughts about these suggestions, and any updates you have for us.

Take care,
Phil