Did the test today; there is no vacuum at idle, but also no vacuum about 1000-2000 rpms. No vacuum at all. help!

 

Hey Suparslinc, sorry man , what 'test' do you mean?? Distributor,carb?? I'm a mechanic ,so I could have an answer if you've got more info

 

According to my haynes manual, if the engine is revved to 1-2000 rpm, there should be vacuum to the distributor through the leading vacuum advance. Around 4000 rpm the trailing is supposed to kick in. No vacuum should be there at idle.



My engine has no vacuum to the dizzy at idle or any other speed.



If you can help out in any way I'd be much appreciative; I can't understand how theres no vacuum to the dizzy.

 

Hey Suparslinc, something doesn't sound right there. Basically vacuum isn't ususally supplied at idle so there's no advancement of the timing at low speeds[not needed basically] But as engine speed increases you need the timing to advance in relation to the RPM of the engine[ie everything is happening quicker so the timing needs to occur earlier to achieve the same burn at the right time], so yes you should have vacuum at your hoses/dissy. I'd say the problem[assuming your pollution gear - all those vac switches on your engine - are still there] lay in the switching systems.

Unfortunately I'm only guessing that our systems are roughly the same between our lands because I have a lot of probs with the REAPS gear[rotary engine anti-pollution system]. Basically, under certain conditions, vac supply to the dissy etc change[ie temp of engine, carb position] so as you could see, one switch being faulty could be it. They're a bit of a complicated system so it's a bit hard to pinpoint your exact problem.

You can check the vac hoses themselves just to make sure they're not blocked. just a word of advice, don't suck on them[as the engine wears you can end up with fuel/oil down these lines and then down your throat :P ]and for splits.

You can check the dissy vac unit easily by removing the dissy cap and pushing the base plate[which is attached to the vac unit by the small rod] and pushing it towards the vac unit. With the hose off the unit, put your finger over the pipe and let go the base plate. If ok, the dissy base plate shouldn't move unless you let your finger off the pipe fitting. A little movement is ok, but if it creeps or slides back you've got a other problem. Good luck.