good morning all,
I have an MBC, what are the synptoms of it sticking or non functioning i am trying to diagnose the chugging on acceleration problem that people have kindly helped me with on previous posts.

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

Hi,
can you describe the "chugging" better - is this engine chugging (could be compressor surge)
Is this a noise that the source is not known?
Is this a stuttering of the engine.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

hi there,

ok, how to describe the chugging.

when i put my foot down the car seems to lose power.
its like accelerates,loses,acecelerates,loses.
when boost goes positive it will still lose power but its like the turbo is forcing it to accelerate, if that makes sense.
i am wondering whether its,
a) an air leak somewhere
b) an electrical, plugs,dizzy maybe not firing a cylinder????
c) an oil pressure/ oil problem ( as i have this leak)
d) Sticky MBC? do these need servicing or trusty WD40ing?
it is almost stuttering diceman.
would there possibly be an error code to signify the problem or highlight any of the above. ( i havent checked).

Is he MBC incorporated in all diving i.e if i am tootling around not neccessarily boosting. is the MBC controlling or is it only in positive boost when reaching the desired limit. that can ruleout any boost controller issues if true?

thanks for your help.
mahender.

one point. i have realised though.
you should all be proud for the help you give especially to novices like me. sometimes the knowledged gained from you boys and girls can make the difference to keeping the car or getting rid.



so a big thanks from me.
mahender.

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

No problem m8 - we have all been there and only through teh help of others are we still owners too (or me anyway!)

Boost controllers work on different types of logic - I believe that most only start to try and control boost once positive pressure is reached (certainly my AVC-R only cycles the solenoid once positive pressure is reached).

Servicing - TBH I would just clean out teh hoses/replace after a couple of years - it is worth checking they are not blocked though!

A miss fire normally produces puffs of black smoke from teh exhaust (unburnt fuel) - I have a small oil leak from teh rocker cover gasket that seeps into one of teh spark plug crevices and occasionally causes this. A good hoon sorts it out - It almost sounds like a back fire on mine though as I think teh unburnt fuel then gets burnt in teh exhaust/turbo.

TBH you symptons sound exactly like you are picking up detonation and the ECU is retarding timing. Thsi shoudl be easily identified by checking for error codes after the car has been stuttering - you shoudl see a code 53 if has retarded timing or Code 52 if you have killed your knock sensor due to excessive knock.

If you have a large hybrid turbo you could also be getting compressor surge, this will soudn like an airflow fluttering sound on hard accelration at low/mid RPM say 3K -4K - the stock turbo shoudl not have this problem.

I woudl suggest to:-
A) check for error codes after the event If none proceed to step 2.
B) Replace all ignition parts - dizzy, rotor arm, plugs & L:eads. Change fuel filter whilst you are there.
C) Check your dump valve is still working correctly (if you have fitted one!) it may have a weak spring and is dumping boost.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

thanks diceman,
TBH you symptons sound exactly like you are picking up detonation and the ECU is retarding timing. Thsi shoudl be easily identified by checking for error codes after the car has been stuttering - you shoudl see a code 53 if has retarded timing or Code 52 if you have killed your knock sensor due to excessive knock.

what is the upshot of this if it is the problemo please. and my options???

i thought detonation causes foobar engine( ever the pessimist).
thanks DM

mahender.
sorry, std tubby, no dump valve just MBC set to 0.9/1 bar.

I recently replaced alternator and battery. could this cause any of the probs.

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

Detonation is not good - it can eat pistons.

I would be surprised though at 10psi of boost in this cold weather.

What happens if you tuirn the boost controller off - what boost were you running with it on - with it off.

Does teh symptom go away with boost controller off?

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

it is a manual bosst controller, so how would i turn it off apart from disconnecting?

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

sorry it was stock boost prior i have had on maybe 7/8 months.

i am wondering could it be something electrical as mentioned previous. if i had a dodgy batt and alt. could it supply too much/not enough voltage to the sparks?

what do you mean your surprised with 10 psi in this weather?
should it not be doing this in these circumstances.

maybe i have run too much boost for the stock internals??

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

10psi is not excessive and in cold weather your intercooler will be working to the best of its ability and hence the liklihood of getting detonation is low.

Could also be worth checking your base timing.
Dodgey battery & alternator are unlikley to show up as stuttering -

I may have soem spare HT leads and dizzy cap if you wnated to test them. Buy a new rotor arm though they are only a couple of quid. Dizzy is circa £60 and leads are £70 ish so wrth testing before buying. Oh and check your plugs. After all this you will need to check your base timing.

Try removing teh boost controller - I assume you are NOW running 10psi then? If you were running 13psi plus there is a chance you are getting detonation - @ 10psi very unlikely

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

what is the rotor arm please diceman? what is it used for?

do you think it may be an air leak either turbo or intake etc....

so i guess error codes are the first check then electrics and i will give all piping a visual check.

would you say my oil leak issue wouldnt cause the stuttering?

i appreciate your help DM .
mahender

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

Yes - check fault codes first.
It could be an airleak - I woudl suggest removing teh rubber pipework between teh turbo and AFM and check for splits. (They are prone to splitting and can collapse under high boost - blocking the inlet to teh turbo - worth a look.

I doubt it is an oil leak - whaere is the leak? is it similar to mine where you find a build up of oil down one of the spark plug recess'?

The rotor arm is located inside teh distributor cap.

Here is a nice piccy - thanks to Kris of a distributor off teh car and claerly showing a very rusty rotor arm.
http://www.gtfours.co.uk/pics/ancillari ... dizzy4.jpg

The rotor arm has a electrical contact taht rotates within the distributor cap to spark each of the spark plugs in series. It basicaly makes a brief contact with each of the electrical contacts on the inside of the distributor cap.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

cool thanks. diceman.

new problem. i ordered a rear drive shaft seal where it goes to the diff
pART NO. 9031135032

the guy doing my car says this is too small. do you know the part no i need?
or is there a link to a site?

the oil leak is from underneath somewhere it is splattering the back of the engine.
the mechanic said it looks like sump area. do you know of any pootential issues it could be.

will try the check list you have said and see.

thanks....
mahender

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

Sorry, no idea on part no. worth trying to get hold of a Toyota EPC (electronic parts catalogue)

Oil leak - likely to be rocker cover weeping down teh back of teh block - that is teh common one.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

thanks mate,
sorry, the part number bit was me in panic mode.
it is propshaft oil seal that i needed i mustve ordered something else ( helpful main stealeers NOT) it will be here on the moro.

is the rocker cover leak a case of replacing a rocker cover gaskett.

does the rocker cover sit at the top of the engine?

because if it does , i do have oil that comes quite far up the engine block, so maybe you are right if its weeping. will ask the garage guy to have a look tomoro.

is this a main stealer part?

mahender....

_________________
THIS IS MY 4. THERE ARE MANY OTHERS LIKE THIS ONE, BUT THIS IS MINE.
red st185, running 10 psi all gears, powerflow cat back, and air filter. oh and fab scoop splitters

Lo,
Rocker cover is the bit of metal at the top of the engine (under intercooler) with Toyota written on it in big writing.

Easy cure maybe to just tighten up teh bolts holding it down - they come loose.

Alternatively a new rocker cover gasket is circa £10 and will take about an hour to fit IIRC. It is the main cause of oil leaks down teh back of block and could be seepeing into one of your spark plug recess' basically thsi causes mine to miss on high boost.

Pulling all teh plugs and checking for lots of oil is a must do by teh dounds of it - coudl solve 2 probs in one! Never that easy though!

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R