ok so I finally got my car moving but i cant stand the boost cut I was wondering what is the best way to get rid of it or if there is a easy way to get rid of it?
1jz boost cut?????
- Thread starter wornoutsupra
- Start date
well first and second i hit about 5 lbs of boost before they start to cut out then when I hit third through fifth i hit about 10 to 12 lbs boost mods I really dont have any as of now i am pretty much just running stock on the motor and my ic which i cant remember the size of and 3 in ic piping
Well first check the gap on your plugs. Should be .028, somewhere close to that. Then it'd be a good idea to check your coil pack wiring... I keep reading things about them needing re-wired or re-wrapped. But fuel cut on our motors doesn't happen until much higher than 12psi. 
Check those things, fix if necessary, and report any changes, hopefully someone else can chime in with similar experiences/fixes. I've been pretty lucky, only ever had spark plug gapping issues.
Check those things, fix if necessary, and report any changes, hopefully someone else can chime in with similar experiences/fixes. I've been pretty lucky, only ever had spark plug gapping issues.
^I agree with the above advice!
I wasn't hitting cut til 13/14 PSI with y pipe and 3'' back w/ filter. Normally at 12 creep to 13 n on cold days 14 boost cut BOO!.
I did have a break up, and i gapped mine to .026 n it worked out just fine
I wasn't hitting cut til 13/14 PSI with y pipe and 3'' back w/ filter. Normally at 12 creep to 13 n on cold days 14 boost cut BOO!.
I did have a break up, and i gapped mine to .026 n it worked out just fine
ok cool thanks deffently will check out those plug gaps. Do you guys know what is normal for the psi thru the gears that way I have a general ball park if i am hitting in a decent range?
Without a y pipe or any other mods in your setup its hard to say if your hitting boost cut at all, it's probably spluttering misfire.
This is hard to read, never mind understand. Do you guys know what is normal for the psi thru the gears that way I have a general ball park if i am hitting in a decent range?
Please be more specific.:1zhelp:
This is hard to read, never mind understand. Do you guys know what is normal for the psi thru the gears that way I have a general ball park if i am hitting in a decent range?
Please be more specific.:1zhelp:
what I am asking like first thru fifth what should be the factory boost peak for the gears if it is any different and also I am running the stock y pipe with the stock twins hope that clears it up a bit
Stock twins, stock y-pipe, 3" test pipe/catback exhaust, stock airbox, I was hitting ~9psi, upwards of 10-11 on REALLY cold mornings (think well below 0*f...). Motor has BC 264 cams and porting/polishing to match, if that matters. I believe "stock" pressure should be ~7-8psi.
ok well i checked all that stuff you told me to and it is still doing it so i dunno it dosent seem to be hurting them but Idk this is basically my first turboed car so I am still looking up stuff and asking a butt load of questions lol, but i did here a loud pop today right after i shifted and the recirc valve opened i checked all my ic pipes and they where all attached so idk what that was at all.
my stock motor (w/ stock ypipe, 3in downpipe, stock cat and catback, 2.5in I/C pipe w/ 3in I/C) i see 10 lbs
I'd say the pop you heard was afterfire (fuel burning in the exhaust). When you let off the throttle really fast the car cuts spark and the fuel that was headed to the engine to be burned shoots out the exhaust. When the unburned fuel hits the hot exhaust system sometimes it lights off with a pop (and sometimes visible flames at night). It's usually worse on a car that's not running right (too rich, a spark misfire, or some other issue).
I was just looking up the stock boost level for the TT 1JT motors the other day and it was 8 psi if I remember correctly. That doesn't tell you much more than you already knew.... there's something that's not working right.
I'd say you need to go over your wiring and look for boost leaks and vacuum leaks. If you don't find anything then test sensors and look for mechanical problems like sticking wastegates (sticking open would be the case for low boost), sticking BPV, clogged exhaust, clogged intake. I once had someone come to me for help fixing a car that was running like crap and I found it had a spraypaint can lid stuck in the intake tube. Apparently it was put there while the motor was out to keep dirt out of the intake, and then left in there by mistake. I still don't know how the car was running at all).
Definetly need more info about what mods are done to the motor to help figure out what it could be.
I was just looking up the stock boost level for the TT 1JT motors the other day and it was 8 psi if I remember correctly. That doesn't tell you much more than you already knew.... there's something that's not working right.
I'd say you need to go over your wiring and look for boost leaks and vacuum leaks. If you don't find anything then test sensors and look for mechanical problems like sticking wastegates (sticking open would be the case for low boost), sticking BPV, clogged exhaust, clogged intake. I once had someone come to me for help fixing a car that was running like crap and I found it had a spraypaint can lid stuck in the intake tube. Apparently it was put there while the motor was out to keep dirt out of the intake, and then left in there by mistake. I still don't know how the car was running at all).
Definetly need more info about what mods are done to the motor to help figure out what it could be.
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like I said before the motor is stock like completly stock lol. Also I will look over and make sure there are no leaks again and what is a good sign that the wastegate is staying open if you guys dont mind me asking
That's another thing I hadn't thought of, the wastegates. However, if only one of them is stuck open, it'll still boost to full pressure, just not as quickly. Before I replaced my y-pipe, turns out the e-clip that holds the wastegate actuator on to the front turbo was missing, fallen off, whatever. Turbo still spooled ~8-9psi, but took until ~4000 rpm to do so. Try wiggling the actuator arms. If they move much at all, there's a good chance that they're not working right. Have a spare turbo around somewhere? You'll see what I mean, how they're connected, etc...
Oh, and I installed a boost controller over the weekend. Did something wrong (not looking for advice here, I'll figure it out, but it is slightly relevant), and was hitting over 15psi. At ~17-18psi, it started breaking up and bucking rather harshly. Fuel cut, so that's not your problem I suspect.
Oh, and I installed a boost controller over the weekend. Did something wrong (not looking for advice here, I'll figure it out, but it is slightly relevant), and was hitting over 15psi. At ~17-18psi, it started breaking up and bucking rather harshly. Fuel cut, so that's not your problem I suspect.
Yeah but if one sticks open or the arm pops off the other turbo has to work overtime to hit full boost. Like way overtime. Possibly even enough to blow the turbo if you're unlucky.
If the wastegate arms are bent they could stick, or if there's something stuck in the wastegate flapper. I even saw a flap door fall completely off once and fly out the exhaust. Just look at both wastegate arms and see if they look like they're both in the same position. They should be. If they're not, look for anything bent or broken looking. That's the best I can describe it. Maybe try to google a picture of the stock turbo's. I'd take a picture of mine, but I don't have a camera here.
If the wastegate arms are bent they could stick, or if there's something stuck in the wastegate flapper. I even saw a flap door fall completely off once and fly out the exhaust. Just look at both wastegate arms and see if they look like they're both in the same position. They should be. If they're not, look for anything bent or broken looking. That's the best I can describe it. Maybe try to google a picture of the stock turbo's. I'd take a picture of mine, but I don't have a camera here.
ok thanks alot guys for all the great ideas tomorrow i will get out to my car and take some pics of the turbos and post them to see what yuou guys thinkif that is fine