JANSPEED TURBO Rocker cover breather (FAO MR F)

Shot2BitZ

Shot2BitZ

Forum User
Techy question aimed at Mike, but anyone else is welcome to chip in.

I have an aftermarket Pipercross cone type filter fitted to my Janspeeded 280. Where then, should the rocker cover breather pipe be routed to in this case?

I thought it was supposed to be plumbed back into the air intake post filter, but pre air flow meter.

The people that fitted my system have stuck a Pipercross breather filter onto the rocker cover breather pipe. This produces a bit of oil smoke which then wafts out of the bonnet vents, which is unsightly and annoying.

The Pipercross filter I chose has a small pipe just behind the foam cone; I intended to run the breather pipe to this small pipe, as the stock setup had the rocker cover breather routed to a similar place. However, they have routed a pipe from some gubbins* on the top of the inlet manifold to this short pipe behind the filter.

* silver/white apparatus which looks a bit like an assymetrical spinning top approx 2.5" across.

Leave it be? Or change it?

Thanks
 
silver/white apparatus which looks a bit like an assymetrical spinning top approx 2.5" across.
Click to expand...

From your description I'm assuming air regulator - has a pipe from each end and an electrical connector on one side (?). If so, this opens a passage from one side of the throttle body to the other to allow more airflow for the extra fuel when cold. Normally the forward pipe would be connected to the back of the throttle body and the rear pipe to a metal pipe which returns to the rubber connector ahead of the throttle body which has a spigot on it.

The rocker cover breather needs to vent into an active airstream ahead of the throttle body - normally on the forward part of the throttle body itself or, on the standard Janspeed installation, to a spigot added to the air filter housing.

The 280ZX is designed to run as a "closed" PCV system and using a filter on the rocker cover will compromise the idle quality when using the original injection. Even a loose oil filler cap or the dipstick not pushed fully home will have an effect on idle stability on this engine.
 
thanks mike,

the engine is hunting for revs, but then again, it always has done.

also, the engine sometimes sticks at 2700 - 3000 revs, which as you can imagine is a bit of an eye opener when trying to stop from speed. it can be cleared with a bit of a heel and toe style blip on the throttle, but it remains an occasional, if annoying and slightly dangerous anomaly. at first i thought it was a sticky throttle mechanism, but even after cleaning and lubricating all possible points from the throttle body back to where it disappears into the bulkhead, it still crops up.

do you think that this could be related to the rocker cover breather issue?

thanks
 
shot
must meet up and compare turbo systems maybe at next AWOL meet
got to get to mikes at some point to have wiring sorted out as the way mines wired it shouldn't work
 
Steve is the Group Organiser of the "Area West of London" Group, otherwise known as AWOL.

They normally meet on the third Sunday of the month at the Royal Oak near Farnham Common on the A355 that runs from the M4 junction 6 to the M40 junction 2 from 12 o'clock onwards.

Steve has also been spotted at the S.E. Z Meets too.
 
gosh. not sure if my old heap will make it that far ;)

i'll definately show my face and quite possibly my 280 at the next SEZ meeting however
 
Sticky throttle syndrome on 280s sometimes related to a wear step in the throttle body itself. Try disconnecting the linkage and operating the butterfly by hand to see if there is any suggestion of stickiness directly at the throttle body.
 
Originally posted by Mr.F
Try disconnecting the linkage and operating the butterfly by hand to see if there is any suggestion of stickiness directly at the throttle body.
Click to expand...

o great master of great knowledge and passer on of technical knowledge
bowdown2.gif
please help me

Being a person of limited technical knowledge I tried to follow your advice and found it made matters worse

Please tell me what I am doing wrong or have I misunderstood your words of wisdom

I disconnected the linkage to the butterfly and tried to operate it by hand and there was a great deal of stickiness there and after clearing up the stickiness and although I couldn't find its throtttle bodyI tried to put it back together again with limited success and it just dosn't seem to work the same, in fact it didn't seem to work at all

It would seem to my limited knowledge that i have screwed up with the way i took the butterfly to pieces and if I get another one could i phone you up as I disassemble the thing to make sure I am doing it correctly as I don't want to keep chasing round the garden trying to catch the bloody things

sorry about this post but I sat just twiddling my thumbs with nothing to do :D
 
Originally posted by Mr.F
From your description I'm assuming air regulator - has a pipe from each end and an electrical connector on one side (?). If so, this opens a passage from one side of the throttle body to the other to allow more airflow for the extra fuel when cold. Normally the forward pipe would be connected to the back of the throttle body and the rear pipe to a metal pipe which returns to the rubber connector ahead of the throttle body which has a spigot on it.

Sorry to burden you with 2 questions at once. Please answer Steve's question first - it sounds a bit more pressing :eek:

I had a quick look at the relevant pipework today:

I can't remember where the forward pipe goes (probably to the back of the throttle body - as it is intended), but the rear pipe is directed forward via a U-shaped metal pipe which then connects to a rubber pipe and then on to the spigot on the air filter.

I did notice a seemingly redundant structure - next to the mixture screw there is a very short length of rubber pipe (2") which appears to be blanked off by means of a round cross head bolt being shoved in it (at least it's not blanked off with a potato - long story, but quite funny - involves Mad Martin - I'll tell you sometime). Should this short pipe be unblocked and connected to something, specifically the aformenioned U-shaped pipe?

I'll bring the car to the next meet, but if you can help me sort the problem by then I'd be forever even further in your debt, as today the cabin was full of oil fumes because the breather filter was acting like a little chimney! It was a sunny day, so you can imagine that my visibility was somewhat impeded :mad:
 
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the rear pipe is directed forward via a U-shaped metal pipe which then connects to a rubber pipe and then on to the spigot on the air filter.
Click to expand...

I think this one should be connected to the blanked off spigot ahead of the throttle body.

the breather filter was acting like a little chimney
Click to expand...

You should not be using a breather filter - the rocker cover spigot should be connected forward to the air filter spigot by continuous rubber hose. Originally this would have connected to a spigot on the throttle body connector pipe which is usually replaced with a plain connector with the Janspeed system, as the air flow meter is moved from its original position to link with the turbo intake. The crankcase lower breather is connected to the relocated PCV valve towards the rear of the manifold, as the valve would foul the turbo in its original position on the underside of the manifold. The original hose is usually extended with a straight pipe connector and an extra length of the same size hose.
 
You should not be using a breather filter - the rocker cover spigot should be connected forward to the air filter spigot by continuous rubber hose.

mmmmmmmm, I know. The people who fitted the conversion were instructed to plumb the rocker breather to the spigot on the air filter - in fact I hunted high and low for an air filter with a spigot for this very purpose!

BTW: Useful info for anyone else with a Janspeed turbo conversion - it's a Pipercross air filter intended for the Escort Cosworth, bought from Xtreme for £71. If you need the part number, I'll dig it out.

It seem that finishing the job yourself is par for the course, so I'll try re-routing the pipes tomorrow

Thanks for the advice
 
I'll bring my 280 to mikes next meet as well so can compare janspeed systems

Steve,

Cool, I look forward to it!

Week tomorrow I think?
 
Mike,

Sorted: Pipes re-routed in accordance with your advice - I had to use heater hose from the rocker to the air filter as Halfords don't stock vac hose. It all seems to work. Thanks.

Just like Columbo - always one more b****y question: I'm low on oil and it needs a significant top up but I don't know what oil was put into the engine after the conversion work - is it safe to mix oils of different viscosities and types? I could always phone the bods who fitted the stuff to ask what oil they used, but I'd prefer not to. Also (sorry - 2 questions!) what's the best oil to use in a Janspeeded 280 engine in good nick? Mobil 1 or a semi-synthetic?

CheerZ.
 
I recommend the Millers Classic Sport Semi-synthetic for the L-series engine these days - a good old 20W-50 with modern attributes. I wouldn't use Mobil 1 in this engine and it doesn't really merit a full synthetic.

Mixing oils is not ideal, but it won't do any harm. Figure on doing an oil and filter change soon......
 
Thanks for the advice.

Yep, oil and filter change was on the agenda, but the 280 and I are off to see Gary Bellamy tomorrow, so I didn't have time to do it beforehand.

BTW: I've now done 350 miles since the conversion (It'll no doubt be around 650 after Lincolnshire and back tomorrow). When or should the head bolts be re-torqued?

Thanks.
 
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