Well the car has just started to play up after running fine all wend with no problems anyway.i went to oban left from paisley so about 83miles so put £40 of shell v power nitro in it and then on the way home just thought if top it up a bit but couldn't find a shell any were close so had to use esso 97 stuff (the best premium fuel they so)anyway got back home car still going gd and everything then was sitting with the car on idle for a wee bit and then all of a sudden it started to idle lump revs was going up and down wouldn't rev right and also noticed the vac on my boost gauge was up at 10 instead of its usally 30 vac so drove it back home and it was horrible was only boosting to like 5psi didn't feel gd at all then as I wa parking the brakes felt weird the peddle was stiff don't know if that had anything to do with it.i think it could be a few think one is the fuel I used the other is coil pack or maybe dirty fuel filter god knows anyone?

fuel wont do it sounds like a vacuum pipe has split or boost leak

That's a vacuum leak, 10 psi vac not good !!

Why would that happen all of a sudden how can I fix it I am not really mechanically minded tbh lol

the original hoses are prone to failure and the most common cause of running problems.... if you cant find the split yourself then take it to a garage and that you suspect thats the problem so they can find it

Were abouts in the engine will these hoses usally be left side or right side underneath on top etc?

Would the fact that I have a dump valve fitted cause this problem?ano that the engines don't like them but I will be removing it once the funds are there after Xmas and get a std diverter valve

if its atmospheric it will affect how tge car runs

Yes it is but it's never done this before.

our cars are very sensitive to any vacuum or boost issues. most people simplify vacuum system and replace boost hoses. that way you can minimise any power loss and ensure the car is running properly... any atmospheric valve is a bad idea on these cars. you need either the original or forge 007 or 008 or the splitter. I have the 008 and makes plenty of noise if that's what you want

I reckon it the coil pack the reson I think this is because it sounds like it's misfireing on idle and even wen I rev it.could this be if so would the vac drop to 10?

Most of the technical conversations here are a bit over my head however, all I can add is that having had coil packs go on about five occasions, they have all been accompanied by the engine warning light flashing on and off.

 

I did have mine start running like a dog one time after filling up at a shabby looking filling station. It took a few refills before it sorted itself out.

Most of the technical conversations here are a bit over my head however, all I can add is that having had coil packs go on about five occasions, they have all been accompanied by the engine warning light flashing on and off.

I did have mine start running like a dog one time after filling up at a shabby looking filling station. It took a few refills before it sorted itself out.

thats wat I reckon the fuel but people say it won't am so confused a hope it is the fuel as it should be a easy fix

Right this is weird just took the at out for a wee drive to see if anything would change for a start still idles horrible but wen I am up the revs it's fine and boost is one going upto 16/18 psi and the power delivery seems ok BUT wen I brake I am not getting much brake and the brake pedal feels really really stiff wat is this someone must know I need to car for Friday for Xmas shopping :-( lol

Its a vacuum leak

Its a vacuum leak

ok how sure are u the guy from the garage is coming tomorrow going to put it on a diagnostics so will this show? Dnt really want to be wasting my money or should a get him to look at pipes etc.would I still be getiring good power if it was a vacuum leak also last question lol is it serious

Brake booster runs off the vacuum too so if your brakes are ropey chances are even higher. You press the brakes it expecting a little help from vacuum. thats leaking = hard brakes 

 

Whip the engine covers off and have a good nose around under the inlet manifold and up the right hand side of the block.

If it does show a code it could be a 17705 code (pressure drop to DV or something like that )

 

Another trick is spraying brake cleaner around the pipe and if the revs rise there's your leak as the cleaner will be sucked in a burnt as more fuel hence the revs rising a little.

At a rough guess when you floor it the engine is using running on boost rather then in vacuum so the vac leak doesn't affect it as much then, although am I guessing on this bit 

Brake booster runs off the vacuum too so if your brakes are ropey chances are even higher. You press the brakes it expecting a little help from vacuum. thats leaking = hard brakes

Whip the engine covers off and have a good nose around under the inlet manifold and up the right hand side of the block.

If it does show a code it could be a 17705 code (pressure drop to DV or something like that )

Another trick is spraying brake cleaner around the pipe and if the revs rise there's your leak as the cleaner will be sucked in a burnt as more fuel hence the revs rising a little.

At a rough guess when you floor it the engine is using running on boost rather then in vacuum so the vac leak doesn't affect it as much then, although am I guessing on this bit

Well was scrolling through the forum there n search low idle and the problem the guy was having is the exact same as wat I am having a puff puff noise comming from the back on the head exhaust sounds bubblyish poping sort of noise wen just sitting and it was all down to the spark plug being lose but to late so check tonight so will do tomorrow so a hope that's the problem as that should be a easy fix :-) if it's not them vaccum leak check will be next I will keep you's posted tomorrow guys

Go on then what's the verdict ??

My car is the same as this. Had a oil change and new spark plugs today and a new clutch pedal switch, which has stopped the exhaust pops and over rev when changing gears, touch wood.

but I suspect a vac leak somewhere as my brakes occasionally go hard. I have done the Y pipe just need to inspect the S pipe over the Xmas holiday along with changing the brake pads.

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Edited 18 December, 201312 yr by mluton

Guy from garage still never came :-( anyway had another fart about with it put my hand underneath the inlet mani and could feel air coming out so must be that but far to dark to do anything so will do it in the morning hope that sorts it.is the vac lines connected some way to the brake servo at all

Guy from garage still never came :-( anyway had another fart about with it put my hand underneath the inlet mani and could feel air coming out so must be that but far to dark to do anything so will do it in the morning hope that sorts it.is the vac lines connected some way to the brake servo at all

Yep. Brake servo needs vac pressure to make braking "better", loss of vac pressure, brake pedal goes hard I believe.

I'll post my findings over the holiday.

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Edited 18 December, 201312 yr by mluton

is the vac lines connected some way to the brake servo at all

 

 

Yarp the brakes take vac off the end of the inlet manifold 

Yes the brake servo's vacuum is obtained from the engine intake manifold via a small plastic non return valve, it's unlikely to be a leak at the servo or non return valve, a leak here would and you would have 0hg vacuum at the gauge and you would struggle to register any boost at all if any, more likely a hose connected to the intake manifold has popped off or split, as you mention a dump valve I would start looking in that area first. As you have 10hg on the gauge it's not a severe leak.

Right manged to get to the garage today and me and the mechanic had a look anyway there's a pipe a plastic hose underneath the inlet manifold which looks like it has came off there is two tho one connected and one isn't and the pipes both come from the bottom of the car from some sort of pump and one connects to the erg valve I think but the other is Defo either came lose or popes out god knows but we are atruggling to find there the hell it's came lose from any ideas guys really annoyingly this lol