The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane around each joint in turn. If the engine rev's up you've found your leak.
Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident.
Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.
Hi. Thank you for replying, unfortunately I have already tried this with carb cleaner and gas, but did not find the leak, I thought it might be the inlet manifold gasket but no leak in, have check absolutely everything with a fine tooth comb, I have it booked in on Tuesday for a complete diagnostic check with a diagnostic expert, if he doesn’t find anything I don’t know what I'll do.
Kind regards Roger
I have already taken all of the vacuum pipes from off the bottom of the throttle and inlet manifold and blocked them all off this includes the one to the large brake reservoir, but still the same.
I think it must be the inlet manifold gasket, but it’s an hard leak to find there, the vacuum does improve a lot when the engine gets hot, probably expanding and sealing the leak somewhat, or it maybe a leak from one of the seals on the petrol injectors I haven’t checked them yet, I tried to see if I could get the seals ready first just in case it was that but can’t find any for this car yet so I haven't checked them.
It might even be the idler valve although I cleaned it and saw it was working.
This car also runs on LPG but it’s the same when running on either.
I know one thing it’s not coming out of that garage on Tuesday until they’ve fixed it.
I shall click the pay you button eventually.
Kind regards Roger.