Turbo Cynos problems, cuts out after 4500rpm

[possum]

Ok here is the story, me and my mates build 5E-FHTE cynos.
So this is what happend:
Bought 1.5L Cynos for $1700 bought blown 4e-fte for $300 with loom, ecu, turbo and engine it self.
We bold everything on, sump, turbo, thermostat housing, injectors, ecu was just matter of unpluging old one and pluging starlet gt one, swaped map sensors around, everything works fine, boosting no problems 0.5bar, untill i found out that headgasket starlet to leak (not beacause of the boost, but cause of the rusty engine inside some body was running on water and after we flushed it twise it starting to leak). I bought new 2.4mm steelhead gasket, replaced it and after everything was done, going for test drive, just passing 4500rpm and engine cuts out, no engine check light nothing, just starting to deaccelerate, like u hitting 180kph speed cut. If i keep accelerator pressed car just deaccelerated, i let go of throttle complitly and then press again, car gose again but untill roughtly 4500rpm.

Things we checked: did diagnostics no error codes, check TPS, Oxygen sensor, Air Temp sensor, water temp sensor, check for vacuum leaks, replaced fuel pump (i have GT4 one now), installed after market Fuel Presure regulator, checked for all vacuum houses if they connect in the right place, cheked for spark plug clearance, tried swaping dizzy from blown engine to mine, nothing helps not even an improvement.

Note: Cut happend only if u press throttle more then 20-30% (basicly depends on the load) and an other thing cut will happen while idling aswell. Didnt had any problems before headgasket, only started doing after.
Also it not boost related as i tried leaving waste gate open and still had a cut.

So what are your thoughts folks? Pretty much is what left is ECU and MAP Sensor, which we didnt touch at all while doing headgasket.

[Elmendorf]

what map sensor are you using?

[YeMs]

hmmm .. blocked filter/injector cups? is the cam timing sweet? does it come on boost? faulty boost sensor at all? siezed turbo? what was wrong with the blown starlet motor?

[possum]

what map sensor are you using?

Proper Starlet GT map sensor, so it senses positive pressure

[possum]

hmmm .. blocked filter/injector cups?
is the cam timing sweet?
does it come on boost?
faulty boost sensor at all?
siezed turbo?
what was wrong with the blown starlet motor?

Fuel Filter: checked and it not blocked

Whats injector cups? I've replaced injector seals with new once so no leaking.

Timing is fine, dont see how it will affect and make such cuts.

If u read carefully i stated, that i left wastegate open and it was still cuting out, with out any boost. Boost comes at about 2500rpms, so i have 1500rpm of good boosting and then cut.

Dont have an other map sensor to try it out, but i havent even touched map sensor when did head gasket, it was reving just fine before headgasket replacement.

Turbo is not siezed, once again it was boosting just fine before headgasket.

Not quite sure whats wrong with other engine, i think piston rings.

[Elmendorf]

Can you start the car up straight after it has happened or do you have to wait a long time?

[Elmendorf]

Checked your igniter and/or coil? We've had similare problems with our engines in the past and traced it back to these two components

[possum]

Can you start the car up straight after it has happened or do you have to wait a long time?

It doesnt stall, its just wont respond on ur throttle, just like hitting 180kph cut. it deaccelerats and then goes again.

[possum]

Checked your igniter and/or coil? We've had similare problems with our engines in the past and traced it back to these two components

ok, this two things i havent check yet. i saw cynos in pickapart takanini today, had those things still there.

But wouldnt it just start to missfire before cutting out?

[Elmendorf]

Not necessarily ours didnt

[possum]

Not necessarily ours didnt

Alright, no problem i'll try to replace them.

But why would it just sh%t it self all of sudden.

Althou i have noticed random missfire on idle from time to time and slight jurking why rolling down the hill, donno if it any how related.

[20v_rollaboy]

i saw cynos in pickapart takanini today, had those things still there.

Ive taken a couple things from that cynos, came in handy Anyone noticed the amount of Hi-Performance leads there are lying around there?

Anyway, when I first got my wagon, it used to idle very rough and almost die, and at times wouldnt rev past 2500. I traced it down to a dodgy ignitor which wasnt grounded properly.

But yours sounds as if its ecu related because its reving fine until 4500. Sounds like its a cut of some sort. Maybe there is a difference between Starlet and Cynos coil? But then you did say that it was fine before you changed the headgasket. Sure you pluged everything back in when you took head off?

[sergei]

We double checked, tripple checked etc.
I think it is ecu relataed as the cut is very clean, in passanger seat it feels like throttle was let off...

[Elmendorf]

Well, I'll have a look at the ecu's I have here after work tonight and see if one of them will be suitable

[possum]

Well, I'll have a look at the ecu's I have here after work tonight and see if one of them will be suitable

Cheers Harlet. mean while i'll go to pick a part and get that coil and igniter

And let u know before tonight if it helped

[possum]

Just replaced Coil and Igniter from same year and with same motor cynos, no improvement it really comes down to ECU, i dont know what else could it be

[possum]

Last night, thanks to 20v_rollaboy, i've tried his ECU and MAP Sensor in my cynos. Damn it.... it was still cutting out exactly 4500rpm even with different ecu and man sensor.

[sergei]

Problem has been solved. Really simple reason, as we did not finish air intake piping, we had 90 degree silicone joint just hanging off the turbo, so what happend the joint was collapsing under high flow, thus creating cut off.
We were planning to finish the intake, but got stuck with that problem (hence postponed the finnishing of the intake), other problem was that we worked after hours and it is impossible to see it if you are not looking for it (it was spotted in day light).
So bloody stupid problem created hell of a lot of frustration...

[tatsumaki]

Great to hear you guys finally got it sorted.

PB.

[Mr Revhead]

So bloody stupid problem created hell of a lot of frustration...

mate if i had $1 for every time i struck that........