Problem?

[w35ty]

Car doing my head in.. Got it back on road now but got no boost? afrs are ok to 3000rpm then shoots to 10.. And dont wanna pull, iv checked actuator that seems ok, checked boost hoses and leak test seems ok.. What could it be? Dizzy? Plugs? Carb? :confused:

[Tony Walker]

is it making any boost at all? huge leak? if its in the 10s then its got the fuel but no air, is your choke stuck on? dumpvalve split? altho this would make some boost. possibly dizzy out, actuator closing the wastegate properely? then dare i say it... cam timing.

[w35ty]

its like its trying to boost can here it spooling but soon as its meant to come in just nothing like aint producing the boost.. Duno what it is aint touched the carb since marky mark set it up.. gonna check tomorrow again for boost leaks and change my leads.. Annoying me now problem after problem

[Tony Walker]

Has it boosted at all since build and just stopped all of a sudden

[w35ty]

nah aint boosted since rebuilt engine got put in mate

[R5MJH]

double check the boost hoses mate sometimes the one that goes on the turbo mate may be at a funny angle and leaks we had this in the past sounds silly but worth checking these avenues first boss

[w35ty]

Gonna double check everywhere tomorrow just head doing wanna get it run in ready

[michael tierney]

recheck the dist.gear

[w35ty]

Gonna have a look at car tomorrow, il check that too

[w35ty]

Checked for boost leak was fine! Holding pressure.. Ordered new plugs as leads gonna see if that does anything

[Tony Walker]

to be honest even with a boost leak, or piped up wrong it should still make some boost pressure.
Maybe try and lock the wastegate shut to rule out the actuator/wastegate. Check chokes not closed, check your getting full throttle.... other than that id say cam timing.

[Brigsy]

Is the turbo ok?

[SCHWARTZ]

My gt2860rs did this when I put an oil restrictor in the oil feed line and it wasn't getting enough oil, drilled it out and boosts fine now. Worth checking turbo is getting oil.

[w35ty]

Car revs all way round when just sitting there just not when driving

iv tested to see if actuator opens when it should- it does

Checked choke seems fine

iv got aftermarket oil pressure sensor plumbed in after inline filter on oil feed and iv got good pressure just over 2bar idle then goes up to over 3 when driving which is fine?

Orderd leads/plugs as thinking they could be shagged? Not getting a good enough spark for the fuel its wanting to burn? thats why im getting 10s on afr soon as 3000rpm..

:scratch::confused:


Turbos done 100mile if that so like new that was from adam-L

[Tony Walker]

afr measures unburnt oxygen in the exhaust not unburnt fuel. rich mixture means no air. misfire would result in lots of unburnt oxygen remaining in the cylinder so would show as a lean mixture.

[w35ty]

Ahh get what you mean mate.. plugs and leads be here tomorrow if they aint gonna do it i aint got a clue what it is :confused:

maybe its a case of checking the timing, what about valve clearances?

[Tony Walker]

if valve clearances where tight youd loose compression permanantly/ more so once hot and engine would misfire and or not start. if you remove the boost pipe off the turbo does it blow any air at you when you rev it? how does the car drive off boost? struggle or drive well?

[Dave Reed]

As already said make sure your getting full throttle.

I done it once, went on the rollers and it came out at 130 bhp, to say I was disappointed was an understatement.. Then the guy running the rolling road said something isn't right, after a quick check it was only half throttle, then I was like :D:D this is going to make good power haha

[w35ty]

when revving the car at stand till itll go all the way around

When driving it seems ok if i stay below 3000rpm then itll struggle afrs shoot to 10 and splutters like have to keep it below 3000rpm

Il check turbo tonight when i get home see if its blowing like you said


Also what was stopping yours from full throttle? Pedal cable? Carb itself?

[Dave Reed]

when revving the car at stand till itll go all the way around

When driving it seems ok if i stay below 3000rpm then itll struggle afrs shoot to 10 and splutters like have to keep it below 3000rpm

Il check turbo tonight when i get home see if its blowing like you said


Also what was stopping yours from full throttle? Pedal cable? Carb itself?


The cable had slipped through the stay clamp on the carb end.

If it's spluttering I doubt it'll be the throttle cable. Have you cleaned the idle jet out?

[tubbyG]

how are your HT leads positioned? are they being fouled by anything, maybe they look ok but are impeded when the engine is under load

I had an issue similar to that where my leads were arcing on the top rad hose extension, but only intermittantly under acceleration

[w35ty]

cable seems fine.. Tonight iv put new leads, checked dizzy drive. Gear postion tried it tooth back any went to 2000rpm then, put it back to normal, got spare dizzy chopped the lugs off so could line up cap with rotor arm bang on stil nothing, drove it gets to 3000rpm hold foot down probs goes to 4000 just over boost gauge only goes to 0.5 bar afrs shoot to 10 and nothing but spluttering and turbo spooling its head off :confused:


Havnt cleaned jet out, worth a try though..

the ht leads seem ok.. Could feel slight arc through rocker cover before when i had king lead in a heat sleeve thing, took it out of that and carnt feel it anymore.. its testing my patience now starting to give up! just wanna enjoy the dam thing:crap:

[Sparkie]

sounds to me as though the wastegate isn't shutting or being held shut properly.....

[w35ty]

:confused: dunno mate, actuator shagged if it is? Could do with one to test it saves spending more money.... anyone got spare could use to test? :D

[Tony Walker]

wether or not the turbos doing anything is incignificant here it should fuel fine with the carb and rev till you lift off... not perfectly but should rev till you stop either way.
somethings stopping it revving. check 100% your choke isnt on.... take carb top off and check it opens and stays there. check your getting full throttle. other than that id say its getting fuel but ur cam timings out. its rich enough with not enough air. even with the turbo off the car it should rev freely. not brilliantly as the carbs not ideal for it but still rev freely.

[Tony Walker]

Consider it a NA engine.. its obviously rich enough to keep going but is starved of oxygen, check the turbos definetly spinning freely too. Should be spinnning on idle really deffinetly with a tiny bit of throttle(you can see this with the air filter hose off)

[w35ty]

Yeah get what you mean mate, il check choke tonight gonna take carb off and give it a clean i think..

I checked the turbo that does spin freely when on idle so? if it aint sorted by the weekend anyone willing to sort it for me? il pay watever ? Just head doing now just wanna drive it!! :crap:

[w35ty]

Well after all that it was the cam timing it was slightly out.. All sorted now with a big smile on my face again:D time to run her in and sort other little bits out ready for meets and shows


Thanks all for the help! and big thanks to sparkie for poping over and sorting few bits out and giving me advice... Top bloke! :agree:

[Tony Walker]

Easily done, it did sound like timing. :agree:

[w35ty]

If any i done that two weekends ago lol left it to the last thing...

[Tony Walker]

Well its best to try the easiest things first but sometimes you just know its the crap one lol.

[w35ty]

Yeah your right there mate.. all sorted now though so back to having a smile on my face(for now) lol