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306-turbo-tom

Limp Mode / Actuator Pipe. 2.0l 8v Turbo Engine.

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306-turbo-tom

just finish my engine and when i took it for a spin last night it started missing and was taking ages to rev out, just wanted to know if this is wot happerens when it goes into limp mode, i think it was boosting to much cause i turned the boost down (well i think) and took it out after work today and it ran fine. but i only brifly looked at the boost gauge and it was reding around 15psi which is to much for this engine. also i have put a mbc on it just wanted to know if i have put it in right, the pipe coming from the actuator does this go to the mbc and then to 1 off the nipples on the inlet. my mbc came with a t-pice thing aswell does this have to be plumed in as i didnt put it in, any help would be great thanks

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bales

Your MBC should only have 2 ports on if it is a dawes type device, you described it the wrong way round but one should be the boost signal from the inlet (the one that went to your boost solenoid) and the other should then go to your actuator.

 

Aslong as your boost signal goes into the right end of the MBC you can't really go far wrong!!

 

(i.e the boost signal goes into the port that is longitudinal to the MBC and the one that exits at 90 deg goes to the actuator)

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306-turbo-tom

car seems to be running ok now, but when i set the boost to about 10psi, it will hit 10psi then drop to about 5-6psi, when driving it, just want to know wot you think it may be, could it be the mbc or boost leak or something, been told it may be the actuator,

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Discostu

when mine used to overboost it felt like hitting a brick wall, ie it was a very sudden loss of power.

 

it would only do it if i floored the throttle below 3000rpm in 5th gear, not sure if it has an over boost function built in?

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tom_m

the xantia will run 0.8 bar all day long, but sometime its complains and flags a stored fault, but a quick reset of teh ecu resolves that. not managed to hit the hard cut yet, but i guess i'm not trying.

 

15psi (1bar+) is waaaaaay more than the oe management was designed to run, on the built in ebc it would boost to 0.4 bar, over-boosting to 0.6bar on hard acceleration.

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306-turbo-tom

thanks, but wot do u thnk would be causing my boost to drop off ? could it be the actuator that needs replacing, or does the actuator arm need adjusting or something?

 

1st gear seems to give some good boost, doesnt seem to drop, probly cause im dont stay in the gear long enouth to realize. but when im in 3rd or 4th and plant my right root i can feel the turbo kick in but then it suddenly drops and doesnt pull like it should. its like the turbo shuts down.

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bales

Depends how much boost it is making and whether it drops off suddenly or gradually.

 

Mine will boots to 15psi but in the higher gears the boost will slowly drop of to about 10/11 psi at higher revs but thats because the turbo can't physically flow the amount of air at high revs to make 1 bar all the way across the rev range.

 

It also could be a boost leak as mine used to leak from the joint on the compressor outlet and that would make peak boost and then in 4th or 5th drop off all teh way down to about 5psi if I kept my foot down. Does the turbo sound at a constant pitch or does it sound odd, mine makes a very loud whistle but when it was leakng you could physically hear it making odd whooshing noises.

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306-turbo-tom

it seems to drop offr suddenly, u can hear the turbo boost up but then when it drops off u cant hear the turbo, it like the turbo stops spinning.

im pretty sure there are no leaks, could it be to do with the mbc, am i better off getting a standard boost controller, thanks

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bales
it seems to drop offr suddenly, u can hear the turbo boost up but then when it drops off u cant hear the turbo, it like the turbo stops spinning.

im pretty sure there are no leaks, could it be to do with the mbc, am i better off getting a standard boost controller, thanks

 

Do you have a bost gauge as you could really do with knowing what it is boosting to. When you overboost i.e about 17psi for more than a few seconds it will cut the fuel and this feels like a bang really as it is very sudden and pretty violent.

 

The standard ecu controlled boost solenoid makes the car a lot lot nicer to drive and the power delivery is a lot better, though unless you chip the ecu i.e solder in a new eprom then you are stuck at standard boost.

 

I know a lot of people say not to use mbc's but mine as have a quite a lot others now run happily at a bar for quite a while now with no issues whatsoever. It probably does run a bit lean at the top but with a 205 being so light then theres not as much load on the engine so thats possibly why there are not as many issues of blown engines!!

 

Its up to you really in repsect of whether you are happy to run the risk of running high boost and letting the ecu do its best, but they do drive nicer with a proper boost solenoid.

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306-turbo-tom

yer ive got a boost gauge but its only a cheap 1, still waiting for a better 1 that i bought, hopefully it will be here monday, my engine didnt come with a stardard boost controller, so i bought a mbc for the min all im trying to do is get it to run standard boost, so i can get the engine run good then mess around with it, so iff anyones got a standard boost controller for this engine let me know how much, thanks

 

 

the other day on the way back from work i think when i pulled off from a roundabout, i planted my right root and im sure it overboosted and went in to limp mode as it suddenly lost power and started missing and s*it, the only way i got it to drive was to press the pedel really slow so the revs would pick up slow otherwise it would jump around and miss, but when i got home i disconnect the battery, then went back out toi it after a couple hours and it seemed fine again, is this wot happerens when it goes into limp mode.

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