took my series 2 out a scoot today.
drives fine if your driving easy, if you put your foot down at 3000rpm the turbo boost comes in and she starts the splutter and backfire.
but if you gradually build the revs she wont backfire at all.
i driv her easy till i got to 4k revs and then put my foot down and she boosted and started to backfire again. once i had the bonnet opened i noticed that she had blown the oil cap off and a blanking plug i had on the inlet. (blanking plug was were a dump valve would normally connect to) and with this unblanked it will not idle or run unless u keep a rev.

i want to know why is she spluttering under acceleration?
could the turbo be over boosting? or has anyone come across this before?
the car lay up for 2 years not being driven and she has cams, uprated turbo and chipped are the mods i know of. if that helps. she did have a dump valve and an uprated intercooler but dump valve was taken off and intercooler replaced with standard.
cheers all

 

Plugs? Could have wrong gaps, Leads, dizzy cap rotor arm, try all these. Could have an air leak? Check all boost hoses and intercooler.

Mine had this problem, took it to Torque of the Devil and the headgasket was gone!

 

jesus dont tell me that :L she will be getting new plugs anyway as at times shes a pig to start

 

Lol, i would try everything else 1st, could easily be plugs and leads, i was just unlucky!

 

decided id put a pic up of the bay to ask were the blocked pipe goes.
see on the inlet manifold there are 2 pipes. on mines the left has a line coming from it and the right is bare. were does this normally go? i know the car had a dump valve at a time and that is the pipe that the dump valve connects to, but my car wont idle now that this is bare. were does it normally connect to?
cheers all

 

bump some one must know :L

 

block that pipe of mate with a bit of piping just put a screw or clamp the end of the piping. that will cause an air leak hence not idling properly

 

cheers lad. yeh had it blocked off but once the car boosted at 4k revs it blew the oil cap and the blocked pipe off. any ideas there? on idle there is no blowby from the oil cap. so im hoping there is no problem with the rings

 

bump before bedtime

 

blowing the oil cap off usually indicates crankcase pressure usually caused by rings or head gasket gone between cylinder and oilway, in both these cases u should be smokin

 

no smoking at all from her. :S shes starting to confuse me now lol im having a look at it today will let you all know how i get on.

 

Sounds like det to me, take if for a set up, have the intake side pressure tested if you can to find any air leaks.

Rob,

 

that barb is originaly for the pcv the car ran out of the facory, yours does not have that now, hence it is redundant and needs blanked off so the car will run!, where does the breather pipe go? back into the metering unit? common with this setup and an old tired cvh, breathes heavily into the metering unit and causes bad running, vent the breather to atmosphere and blank off the metering unit, see if this helps. PS i doubt it will have "cams" as cvhs only had the one

 

what do you mean they only had the one? by cams i mean it has a fast road camshaft.

sorted the problem now people. she was overboosting. have the boost set down a bit now and shes running grand and the breather is blanked off.

 

Breather cant be blanked, it would be very smokey and not run well at all, you mean cammed then? it cant have cams if it is sohc. Glad you sorted the problem, i wonder why the boost level changed from its previously fault free setting? did you find the source of the problem?

 

Sounds like the spark plugs were'nt up to the job on high boost!

 

i blanked that pipe on top of the inlet. yeh shes cammed sorry we use a different phrase this side of the water :L
she has a boost regulator i think you would call it and it had loosened a couple of threads making her boost alot more and backfire. il get a pic up of it now soon

new plugs coming tomarrow so then she should run better again,

 

Ah i see.You mean bleed valve or the actuator loosened...

 

likely lol im learning everyday about these cars lol



thats the thing there that we had to screw back in a couple of threads

 

So it was detonation.... the destroyer of cvh's

Rob,

 

thats your bleed valve mate, but to be honest ive never had one come unscrewed even slightly so either replace with a lockable one and put it somewhere people wont be tempted to touch it

 

in a bin?

 

I've seen these unwind themselves, bin and get a lockable one then have it setup to be sure the fuelling and timing is correct asap!

 

If you do buy another bleed valve,be careful if buying off ebay,they fall apart!

 

yeha get a turbo smart one.

And When you do anything to you car like intercoolers and fannying around with the boost. i would advise a setup OR at least check the basics fuel press, a/f and gaps , leads,plugs etc .....

 

Agreed, but prehaps not the fuel prssure on a k-jet rst, certainly would not do any harm to install a wideband gauge and check afrs, and also set the ignition timing with a strobe.