1JZ boost leak

MK3MKB

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This is not on a Supra, but I figure this would be a good place to find an answer. I have a '94 Chaser 1JZ-GTE automatic. The car drives completely fine under normal driving not on boost. When I try to take off and get into boost I can hear the leak especially next to a concrete wall/sound barrier. It also won't pull all the way to redline, it slowly gets up to 5K RPM then shifts. If I'm already rolling and try to get into it the revs raise but the car doesn't downshift right away, then it drops a gear and same problem as trying to boost from a stop. I've leak tested the inter cooler and piping, didn't find any there. The TRC light has been on since I bought the car, unsure if its related.
 

A70nut

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I'd probably be trying to figure out the trac light, there's a possibility that the car could be in limp mode if the trac system has a fault code, or the non vvti traction control throttle body flap is staying shut when it shouldn't.
 

MK3MKB

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I'd probably be trying to figure out the trac light, there's a possibility that the car could be in limp mode if the trac system has a fault code, or the non vvti traction control throttle body flap is staying shut when it shouldn't.
I've thought the throttle body flap may have been an issue. I know its open when the car is off from when I checked the intercooler piping. I unplugged the throttle plate actuator, no change. TRC light still on. I have an OBD-1 reader, I'll try and connect it to see if it tells me anything.
 
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MK3MKB

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I couldn’t get the reader to communicate. I was poking around this weekend. I isolated the turbo side and leak tested it. found one small one on the union for the front and rear turbos, just loose clamps. With ~15 psi in the pipes the waste gates on both turbos stayed closed, but I could open them easily with a screw driver. Checked the intercooler piping again for good measure, no leaks. Test drove, still no change. I do hear air rushing on acceleration in the turbo area under all throttle levels. I thought possibly I could have a bad recirc valve so I removed all hoses, and capped them. I capped the line coming from the charge pipe to the recirc valve on the charged side. Test drove again, this made it worse. It would now shift at 4K rpm instead of 5k rpm.
 

A70nut

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Sure you dont have a huge boost leak somewhere after the throttle body? Iacv and its related piping arent leaking?
 

MK3MKB

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Sure you dont have a huge boost leak somewhere after the throttle body? Iacv and its related piping arent leaking?
I went ahead and pressurized the entire intake system, absolutely no leaks to speak of. I swapped out the recirc valve, no change. Today while driving it I noticed there wasn’t much difference in acceleration on say 50% throttle and 100% throttle. Still revved to 5,000 RPM. Also won’t spin the tires from a stop in the rain. This make me wonder if it’s a TPS issue or a MAP issue. I also found my air rushing while acceleration noise to be the Down pipe flange missing a gasket.

I didn’t mean to go 2 weeks without an update, got busy with house renovations.
 

A70nut

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I went ahead and pressurized the entire intake system, absolutely no leaks to speak of. I swapped out the recirc valve, no change. Today while driving it I noticed there wasn’t much difference in acceleration on say 50% throttle and 100% throttle. Still revved to 5,000 RPM. Also won’t spin the tires from a stop in the rain. This make me wonder if it’s a TPS issue or a MAP issue. I also found my air rushing while acceleration noise to be the Down pipe flange missing a gasket.

I didn’t mean to go 2 weeks without an update, got busy with house renovations.
Does it feel like it's making boost at all? Turbos dont make any strange noises?
 

f00g00

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Did you check for codes on the diagnostic plug?
Do youhave a boost guage?
 

MK3MKB

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The car does not feel like its making boost. No boost gauge. Problem also seems to be getting worse. The other morning I went to over take someone and I had the usual rev up but go nowhere but this time it dumped a bunch of black smoke before it started accelerating. It also has a really hard time gaining speed on hills. Only noises I hear is a belt squeal above 4,500 RPM. Another thing that confuses me is if I keep it on the floor it maxes out at 115 KPH and revs to 5,700 RPM, Seems to get stuck in that gear until I lift and let it shift. I have eased the car up to 130 KPH no problem. I have ECT power on, seems to run better that way.

-thought timing may be off, pulled cover and verified timing marks match.
-checked compression, found good. values at bottom of post
-checked resistance of crank angle sensor. 1183 ohms
-checked resistance of front cam sensor. 1230 ohms. also had oil inside the connector, cleaned.
-unable to check rear cam sensor due to access.

Compression test reults:
1-170
2-165
3-175
4-170
5-165
6-165
 

f00g00

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You still haven't read the codes properly on the diagnostic plug. You have to jump Te1 and E1. Then turn the key on without starting the engine and count the flashes. The plug should be on the left side of the head.
 

MK3MKB

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You still haven't read the codes properly on the diagnostic plug. You have to jump Te1 and E1. Then turn the key on without starting the engine and count the flashes. The plug should be on the left side of the head.
Never pulled them because the light wasn’t present. Car wouldn’t start randomly over the weekend again. Pulled codes when I got home from work today, has a code 14. Car fired right up today when I tried it.