celica gt four turbo troubles?

[JRDUNN]

i recently bought a gt4 about 3 weeks ago now and after handing 3k over for the car ive went and had the rear arches rolled to sort the rubbing of the rear wheels because of the comically wide tyres the last owner fitted. other than the Axis deep dish wheels a HKS dump valve, a Nur spec R exhaust and a Starbo turbo timer the car is totally standard.

up until today the car has given me no issues what so ever but after a quick trip out in the car and on down changing for a roundabout the whole car starting bucking, while nursing the car back to my office i found that it ran fine under the turbo but when driving within the turbo it kept boosting and then dropping off. this has worried me badly.

ive had it suggested to me that the actuator may be to blame (best case) or the turbo is knackered (worst case)

any other theories. or indeed help on how to tackle the actuator as i am to believe a monkey as idiotic as myself can be instructed as to how to check that isnt sticking...

?????

thanks

[LandingSpot]

You don't mention which generation... Put a pic in your profile. Or some more pics in Reader's Cars

For it only to be a problem when the turbo is boosting, I think it sounds actuator related. Perhaps you are hitting fuel cut (due to the turbo boosting too much) at 1.3bar. If you are handy with the spanners, take a look at all of the pipes surrounding the turbo and actuator. Split pipes would leave no vacuum which would keep the wastegate shut which would cause fuel cut.

If you are not handy with tools, take it (by trailer if necessary) to a specialist. Depending on where you are will dictate where you go. Tuning Developments are in Warrington, but I guess this is a little far. Don't drive it if you cannot do a safe speed without boost as excessive fuel cut WILL nuke your pistons!

Another option would be to sign up to the owners club www.gt4oc.net and get a member local to you to pop round and take a look before transporting it.

One thing is for sure, don't give up on it, they're great cars!!

Hope this helps!

ETA: Spelling and grammar

Edited by LandingSpot on Friday 8th July 23:05

[MikeyMike]

Good reply above. If you're lucky it could well be something as simple as a vacuum leak from a split hose. I have an MR2 Turbo which as I'm sure you know uses the same lump. When I've had vacuum leaks the symptoms can be very worrying indeed! Id remove, inspect, and refit all the major hoses to and from the turbocharger then take it for a spin. Also, with the MR2 you can check for error codes very easily, I'm sure a fellow GT4 owner will be able to advise if this is also the case with the GT4.

[LandingSpot]

I'm only familiar with the ST205 and they can be checked with a paperclip.

Not sure on the older models, but engine wise they are more similar than you'd think.

[JRDUNN]

yes my grammar is abit poor in that above post, i have had my mind focussed on the possibility of huge repair bills.
thanks for your replies; i will go and have another scout round the actuator if you are all of the opinion this is a likely culprit. the car is a gen 6( im still not completely familiar with individual models, having only found there was such a think as an st165) st205 import model.

my mechanical skills are basic but i have refitted a turbo to my previous glanza before so maybe i give myself less credit than i should. warrington would be half the country i think, ive heard there is a skyline specialist within 7 or 8 miles from here that has just opened so that may be where i turn if i cant find the issue myself.

yes im aware the mr2 turbo and celica share the same innards, im full of trivia knowledge on what shares what with what and 0-60 times and bhp figures..... but this is all just car park nonsense as when push comes to shove im useless hah.

as for the paper-clip suggestion, could you maybe explain how i go about this, much appreciated.

i will be checking the pipes and actuator as soon as possible and will post if i sorted

cheers

[LandingSpot]

I meant my spelling and grammar

Go to this site

http://gtfours.co.uk/

under How To, click check error codes -> ST205 ECU

[JRDUNN]

right, ive checked error codes, i have a 54 error which is intercooler fluid. so i started the car up to check that first of all. and then the cars engine just gave up the ghost in idle. did get the chance to even look at the hoses....
:s

[JRDUNN]

didnt* get the chance to look at the hoses.

[LandingSpot]

is that the only error code you get? it will flash them sequentially. if it flashes five times - break - flashes four times then repeats, then you only have one fault code. you ned to leave it going longer to see if you have any others. I would have thought your symptoms would have thrown something else.

you don't need to have the car running to check the codes or the hoses. just look for signs of damage, corroded or frayed pipes . Have you signed up on the OC yet? I am sure there would be a member local to you.

[JRDUNN]

i will be signing up at some point today.
definitley just one error code for 5-4 i made sure there wasnt anymore after that. by the sounds of it mr AA may be taking a look at it later today. thankyou homestart...

[JRDUNN]

i think ive done it!
ive sourced the problem to a faulty fuel readout. so its telling me i have 1/4 of a tank and i have hardly any, causing the car to drag more fuel than there is the tank when going into the turbo, this also explains the reason the engine slowly ground to a halt in idle. thankfully there must have been a tiny amount of petrol still in the lines so after filling the tank and taking it out for a ride its all working fine again. hopefully it stays this way

ive also managed to reset the ecu wiping that nasty orange light off the dash at last.

thanks alot for your replies

[LandingSpot]

No problem mate! Glad you got it sorted!!

[RobCrezz]

Whoops!

Make sure you use 99Ron super unleaded.

[JRDUNN]

well i sometimes have to make do with 97ron excellium (total garages) but i never fill the tank with this. 99 is available at a tesco on the way to work so usually pop in there.

[Red Devil]

If you have run the tank virtually dry, check (and if necessary replace) the fuel filter. It may well be filled with crud which won't help with flow on WOT and you don't want any really small particles clogging up your injectors either.