Help New Supra Owner

[bloater]

hi! new to this so don`t know if anyone can help me? i`ve just gone out and bought a 1992 supra 2.5 tt r! and want to know what mods i can get? she`s got a hks bov. hks air intake, and hks cam belt. also want to know what goes wrong with these cars? basically need to/want to know if i got a bargain or a banger! cheers

[Flat Pack]

Induction kit, decat and exhaust are supposed to be good for quite a few horses... Heard people claiming 30 odd extra just from those mods, but that seems a bit excessive to me. Mine will be on the RR soon so I guess I'll find out :)

If you want to go much further than that you'll have to think about the turbos, they're perfectly happy at stock boost but give them much more and they have a reputation for blowing turbo seals.

They don't tend to go seriously wrong if looked after, bits will need replacing from time to time but it is a 15 year old car now ;) I've only come across trivial common faults so far, such as the blowers not working at all speeds and the climate control going a bit trippy and only blowing hot when it feels like it. Easily fixed though :)

Gratuitous pic of my car that I took at the weekend...

[Karma Supra]

Pretty much any chassis/body mods are the same as the uk 3.0 turbo, engine, pretty much anything really!! what do you need?

The "R"s are fairly rare and sought ofter so please mod it wisely and tastefiully!!!

Welcome to the club ;)

Anything you need to know, just ask!

[bloater]

the only problem i seem to have is that when i floor it after a second or so the turbo seems to burble!? it`s like there`s more power there but the turbo won`t let me have it!? a friend thinks it`s the plugs or ht leads! apart from mentioned mods engine is stock but has a stainless exhaust and has been de-catted! try to get pic up soon! i was thinking about upping the boost or maybe getting some spike valves fitted to give me a little bit more power if ineed it! cheers for the info.

[Karma Supra]

What do you mean by burble? What is it boosting at?

It won't be the HT leads.... - it doesn't have any!

[Flat Pack]

Yeah is it actually making proper boost? The stock boost gauge is a bit pants, but should show you if you've got a real problem.

Mine hits the top of the gauge and stays there when I floor it (unless I'm at like 2000RPM or something :P)

I did have a slight misfire under load which was cured by new plugs, coil packs failing aren't unheard of either and that tends to get worse when the engine is working hard too... They're coil on plug as Karma said so no leads to worry about. While I was changing the plugs I noticed I had a bit of oil in the cam cover valley around the number 6 plug, don't know if they tend to blow the cover gasket around there but mine was overfilled with oil when I first got it... It hasn't come back since.

[bloater]

it`s like once i`ve floored it the turbo reaches its peak then it seems like it cuts out! the best way to describe it is that it burbles! there`s no more power, if i change gear too fast from 1st to 2nd when i get to 2nd gear the burbling is there basically there`s no turbo! that`s the best way i can describe it! is it knackered? if you want more info just ask, i think you know more than me. once it hits the top that`s when it cuts out! stock dash so top boost 6

[Flat Pack]

Sounds like maybe you're overboosting and hitting fuel cut.

Basically if there's too much boost the ECU stops sending fuel to the engine and everything stops. Its a safety measure to protect the engine and turbos from damage from too much boost, the mods you've got will increase the amount of boost but I don't know if it'd be enough to hit the fuel cut normally though...

The stock gauge reads in 100s of MMHG... the top of the gauge (6 on the gauge so 600 MMHG) is 11.7 PSI, I'm not sure where fuel cut is but 14 PSI rings a bell.

Aftermarket boost gauge that reads higher and more accurately might be a good investment, at least you'll have a better idea of what's going on then.

[bloater]

i took it to a garage yesterday for a diagnostic, he said th ecu`s fine and that it was the plugs and leads!!!!! but because of the car i don`t know where to take it!? most of them didn`t even know there was a 2.5 ttr supra! would i need to put it on a r.r.? it only happens when i really thrash it! say when there`s a scooby in front that i just have to overtake! don`t think it`s fuel cut because the engine doesn`t stop dead it`s like a rev limiter but on a turbo, the engine still revs but the turbo won`t go!!!!!? if i treat the car like normal it`s fine. not sure what to do??

[Flat Pack]

I'd have expected the garage to notice it doesn't have proper HT plug leads even if they didn't know the engine, so I dunno how far I'd trust them ;) Spark plugs are easy anyway :) NGK BKR6E, gap them to 0.8mm and away you go. Probably about £10 - £15 for 6 so you might as well bung a set in and see if it fixes it.

The engine is pretty much the same as the 2.5TT Soarer (slightly different turbos I think?). A decent import specialist should be able to look after it easily enough.

Could be that your BOV isn't fitted properly? I'm not really up on turbos and things (this is my first forced induction car), but as I understand it should have a feed from the inlet side of the engine somewhere... If that's not connected the only thing stopping the valve opening while you're on the throttle is a spring... Build too much boost, overcome the spring and the valve opens and all your lovely boost escapes.

[bloater]

Can i be really stupid now!!?? and ask how fast your turbo needle goes up? mine goes from -2 to 6 in less than a second?! no matter what gear your in. Is that normal? gonna change plugs at weekend to see if that helps, no one from derby has a car like this so nobody to talk to!? this is my first turbo`d car so maybe i`m just panicing about nothing!?

[Karma Supra]

Sounds like fuel cut to me, - which should show up with the ECU in diagnostics mode, -does the engine warning light come on when it stutters?

AS for the garage saying its HT leads, I'd stay well away!

A plug change is definitely worth doing, while you are at it I'd also do an oil and coolant change, but I'm fussy.

Out of interest... is it revs/boost related or does it aways do it at the same speed? you could still have the speed limiter on there! Has the car been converted to mph?

[Flat Pack]

Can i be really stupid now!!?? and ask how fast your turbo needle goes up? mine goes from -2 to 6 in less than a second?! no matter what gear your in. Is that normal? gonna change plugs at weekend to see if that helps, no one from derby has a car like this so nobody to talk to!? this is my first turbo`d car so maybe i`m just panicing about nothing!?

The gauge on mine flies from bottom to top quickly in one movement, I'm not sure how long it takes as I'm normally too busy watching the road when it starts really shifting... It gets there very quickly though. It then stays glued to the top of the gauge until I back off or change gear. Does the gauge drop back down when you start having trouble (might be best to get a passenger to watch if for you ;) )

Out of interest... is it revs/boost related or does it aways do it at the same speed? you could still have the speed limiter on there! Has the car been converted to mph?

He said it happens in 2nd gear so he's unlikely to be bothering the speed limiter... That's more like hitting a brick wall anyway :P

I've never encountered fuel cut but I thought it'd be more like the speed limiter, everything stops working completely and you start slowing down for a moment before it picks up again. Sounds like its suddenly losing boost for some reason, the fact it reaches the top of the gauge suggests that there's no constant leak and the turbo is OK though.

[bloater]

took it out tonight for a quick go! the needle goes to the top then it starts to burble!!?? like when you start an old car up un the morning and it`s not firing on all cylinders, when you floor it thats like the sound i get! a burble!! no lights come on! the engine still tries to rev but no turbo the needle on boost gauge doesn`t go back down! also tried staying in 2nd at 2500 revs then floored it, it burbled again then the turbo eventually came in! is it just misfiring??

[Flat Pack]

Yeap sounds like a misfire and quite a big one at that... Wouldn't call it a burble myself but there you go ;)

Try some new plugs as a first step as they're cheap and could probably do with a change anyway.

[adi]

First off.. i'm in derby.. i'd happily pop over and take a look as i know the JZA70 inside out. I've owned one for five years, (and i started/run the owners club, but we'll keep that quiet :D ).. i'm the first to say i'm not a mechanic but i know exactly how the engines should feel, what they suffer from, what goes wrong with them and what mods will have been done or not done.

when these cars first start to hit fuel cut after an ECU reset or Battery disconnection , it wont be a complete cut off, but a mild cut off whilst the ECU tries to suss out whats going on. You'll also get past the standard cut off point. Eventually, as the ECU learns a bit more it will cut it dead.

You could be experiencing that.. but your 'burbling' sounds like ignition retardation to me (especially since you're almost certainly running 5psi under the boost cut level unless your car has some mods).. This means your TPS (throttle sensor) could be out or other similar problem.

A word of advice though.. DONT take it to a garage.. DONT take it to a toyota dealership.. and DONT take it to a mate who's handy with a spanner. Take it to a specialist who knows what they're doing. Being in derby your best bet would probably be thor engineering in Warwickshire.

As for mods.. getting around 320bhp is easy enough with a full free exhaust. BUT, nobody makes them for turbo back 1JZ's.. so its either a custom fit or a bodged 3.0 exhaust. BEWARE THOUGH!!!!! freeing up the backpressure by fitting a freeflow exhaust regularly causes turbo seals to blow. And you definitely dont want that.

After that, modding is difficult, and expensive. It basically involves replacement turbo/s, replacement injectors, map sensor, replacement fuel pump and FPR and replacement ECU... plus a good tune up :D Budget around 3-4k.

PS the owners club is at www.forum.mkiiisupra.net

[bloater]

where abouts in derby are you?? i`m in chad!! if you know what your on about, i`ll happily let you look!!! hoping it is just a misfire though!!

[adi]

i'm just down the A38, not actually in derby.. nearer burton.. but i'd happily pop over tomorrow/sunday if you want. Like i say, i'm no mechanic or tuner.. but i know what a misfire/igntion problem or fuel cut feel like on these particular engines... and i know most things about them.. :D I wont be in mine though.. its off the road over winter.

[bloater]

on that other site you mentioned!! there on about doing a mini meet, i thought i might go! are you going! can`t make this weekend as i am preparing to move house.

[adi]

possibly at the midlands meet.. although i dont tend to go to many if havent got the supra :D

[trixster]

its sounds like what your describing is the same problem i had i thought it was a missfire it ended up being a head gasket now ive got more problems if anyone doesnt mind

ive just done the head gasket on my mk3 supra 3.0i turbo 7mgte

it all went very smoothly untill i hit the Battery with a spanner (or it was the broken earth wire on the starter that did it ) ive lost all power to the ignition and the windows clock dash mirrors seats and central locking etc i have still got head and tail lights fuel injection etc

i cant find whats wrong and if i dont my missus is gonna kick me out coz i need the carto get work please help me we are sure its a relay or fuse but dont know which does what

its more of a v8 gurgle than a burble lol sounds like your slowley revving a v8 up to its mid revs sort of a chugga chugga chugga thats what i had i also had that oil in port 6 plug too that was mentioned earlier thats gone now too

if anyone can help me ill mail you my number

hope you get your tt r sorted