Supra not boosting over 0.5 bar

note that I just picked this car up and all modifications were done by the previous owner.

Also it was not driven in 10 weeks. Maybe 2km max (for shipping purposes).

has the following upgrades and more..

mishimoto radiator

blitz intercooler

greddy twin intake

blitz nur spec catback exhaust

blitz turbo timer

stock cat no downpipe

when accelerating full throttle it will hit 0.5 bar on the Blitz gauge and then stutter and won't go above. When it hits 0.5 bar its almost sounds like rev limiter. Turbo's just won't spool anymore.

btw it has stock BOV and its pretty loud spool, is the stock BOV fairly loud?

am I hitting fule cut, boost cut, or .. ? any ideas guys?

ECU is stock with no BCC or nothing.

Have you checked that all vacuum pipes are connected properly and not perished/split?

IACV VSV?

Have you checked that all vacuum pipes are connected properly and not perished/split?

 

IACV VSV?

No I haven't. I'll take thurrow look over them tomorrow.

Is it a J-spec or US spec Supra?

The stock blow off valve is silent, as it recirculates the air back into the intake. Are you hearing the sound as the car is accelerating or only when you let off the throttle? If it is a constant noise then it maybe a leak somewhere, if it is only when you lift off then either the stock BOV is venting to atmosphere or it has an aftermarket BOV fitted. Can you post a pic of the engine bay showing the BOV?

If it is only making 0.5bar it won't be fuel cut. Fuel cut only happens above 1bar, it won't make the engine 'stutter', it completely cuts the power.

The 'stuttering' may be a misfire, I'd start by fitting new plugs and checking all the coil pack connectors, the connectors become brittle over time due to the heat of the engine and can cause misfire. If there is a problem with a certain spark plug/coil pack/coil pack connector you may find one of the spark plugs is blacker than the others.

Check all the vacuum hoses are connected up properly (see links below).

Check intercooler pipes for leaks.

FAQ - Spark Plugs

FAQ - The Sequential System

FAQ - Sequential Turbo Hoses

FAQ - Sequential Turbo Problems

FAQ - Refurbish coil pack connectors

ye I'd say a intercooler pipe has just popped off

ye I'd say a intercooler pipe has just popped off

If an IC pipe had popped off then it wouldn't make any boost pressure, though could well be a leaking IC pipe.

Before I bought the car the seller has the car inspected. The Toyota mechanic in Japan said that he recommended an aftermarket ECU due to the boost issue. Really I wouldn't need that maybe just a BCC?

And yes this Supra is J-spec.

I get the whoosh sound only when the turbo spools. So when the turbo start to spool and let off the gas it will make the whoosh sound. The most boost the louder... althought it will spool to 0.4 bar max.

I'll check everything over and let you guys know.

Sounds like one of the intercooler pipes is partly off or split. The number of times people have said "no, they are fine, I have checked them a dozen times" and within ten minutes I find one that's not properly secured or split is unbelievable. Start at the throttle body and check every hose joint and every rubber hose for insecurity, or splits. Choice one is down the side of the battery where, on stock piping, a clamp holds the IC pipes firmly to the bodyshell, masking when the joint between plastic and rubber is partly separated. Go right under the car to the outlet side of the IC, check the I/C itself for damage, then take the RH front arch liner off and check the inlet side of the IC and back up to the exit pipe from the twin turbos. I have a test rig to pressurise the system from the TB to the turbo exit pipe, with compressed air, but a physical inspection is all that's necessary. If it's not a pipe issue come back and I'll see what else seems likely.

if you don't have any joy with the above, I had the exact same problem which turned out to be an ill fitted fuel pump washer. my aristo is different to the supra in terms of a few things, but when the second turbo should of been on full power, the pump couldn't provide enough fuel. hence the feeling that the turbo has run out of puff.

I had that issue on a customers Vertex, someone had fitted a Walbro pump but it didn't sit correctly in the carrier and 1/3 of the flow was going right back into the tank, from memory.

I had that issue on a customers Vertex, someone had fitted a Walbro pump but it didn't sit correctly in the carrier and 1/3 of the flow was going right back into the tank, from memory.

that might of been mine if you work at tdi?

Have you checked that all vacuum pipes are connected properly and not perished/split?

 

IACV VSV?

I was going to say VSV, Sounds like the second turbo not coming in.First one boosts to 0.5 bar second one 0.9 If i remember rightly.

thanks guys if nothing is solved within a couple days i'll check back

Aside the boost issue I had some other larger problems. This is only the 2nd day I am driving the car after the 10 week shipping process.

I'll try and explain what went wrong today. Basically today alone I have drove approx total time 2 1/2 - 3 hours. I had my car parked... started it up and was driving for about 10-15 minutes in heavy traffic. Then suddenly I get the warning light on my dashboard comeup. Also the battery icon lights up.. and another one beside it to the right (looked like something to do with over heating). Anyways when this happened my sterio shut off, all my interior lights dimmed and my headlights dimmed as well. I pulled over in the parking lot and turned my car off due to this issue. I tried starting it back up and battery was dead. I had my friends roll by car forward while I was in 2nd gear and clutch engaged. I released the clutch and it fired right up (just a trick if battery dies). At this point the car is idelling very high (about 3000 - 3500). I went into neutral, reverse, first gear... and the RPM did not drop. I turned it off tried everything again and it was still like that. I drove out on the road and in 2nd gear the engine was revving very high (you could just hear by it)... but the RPM showed zero. So I had enough and just parked the car and got it towed home. Also my oil temp was twitching back and forth strangly when I turned the egnition on and off with the key.

I'll be getting it checked out Monday. I'm hoping its just a shit battery and I need a new one or with the strange revving issue just something with the ECU?

and sorry for bad grammer/spelling if it is, didn't check it over -_-

That issue is almost certainly a failed or failing alternator, or an earthing issue between engine and chassis or engine and alternator. A totally goosed battery *MAY* cause it, but it would have to be really knackered. Very generally speaking alternator failure on MKIV's is often due to water from a leaking water pump getting in them. There should be a short rubber hose on the nipple under the water pump to direct leakage past the shaft seal AWAY from the alternator. See if it's there or not, and if there's any dampness coming out of it. Oil ingress will kill the alternator, too. They won't like salt water in them either, if the car's been shipped on deck.

That issue is almost certainly a failed or failing alternator, or an earthing issue between engine and chassis or engine and alternator. A totally goosed battery *MAY* cause it, but it would have to be really knackered. Very generally speaking alternator failure on MKIV's is often due to water from a leaking water pump getting in them. There should be a short rubber hose on the nipple under the water pump to direct leakage past the shaft seal AWAY from the alternator. See if it's there or not, and if there's any dampness coming out of it. Oil ingress will kill the alternator, too. They won't like salt water in them either, if the car's been shipped on deck.

I was told it could be the the alternator by a couple people. So that could be it have to get it checked out.

btw the engine seems to be very hot always when I open the hood. The temperature on my dash is in the middle... engine revs at like 1.5k as well.

Normal operating temp is in the middle of the stock gauge. Twin turbo 3 litre engines throw out a lot of under bonnet heat, it's the nature of the beast.