Mad4slalom
Well-known user
Hi Teamz, I put the pump before the filter and check valve , just replaced the running engine with the vac pump to create vacuum .
Vacuum issue .
- Thread starter Mad4slalom
- Start date
Mad4slalom
Well-known user
I didnt overcome the problem , the problem was exactly the same with the pump as with the engine running. just when I start the engine, the headlights and wiper door open then close once, I presume this is until there is sufficient vacuum , then they work perfectly , Until the next time I start the engine when they open and close once. Baffles me
Mad4slalom
Well-known user
As soon as you start again they just open once , (on their own) the passenger light is slower to open and close than the drivers side at this point. Once they have closed and I am driving or am stationary with engine running then they all work normally , not sluggish or uneven and The over ride switches work. They are slightly slower at idle as the motor is cammed . This “opening “ happens Every time I re start the engine. As I say, two years ago it suddenly fixed itself until now
thank you for your help and thoughts on this .
teamzr1
Supporting vendor
So sounds like you might want to look on the right side actuator and relay valve
You know what the LSA (Lobe separation) is with that 3rd party CAM ?
If too narrow like around 112 LSA or lower, there is very little vacuum for startup and low RPMs
Some of my customers have to go with a larger reserve vacuum tank, esp if power brakes are effected
as this allows more stored vacuum at the low end
You know what the LSA (Lobe separation) is with that 3rd party CAM ?
If too narrow like around 112 LSA or lower, there is very little vacuum for startup and low RPMs
Some of my customers have to go with a larger reserve vacuum tank, esp if power brakes are effected
as this allows more stored vacuum at the low end
Mad4slalom
Well-known user
Thank u teamz I will look up the cam spec in a minute, I wondered if the sluggish passenger side headlamp was a clue but couldnt see how it was linked to the wiper door . I did find another vacuum port on the carb with a perished and leaking rubber cap, have some new caps arriving tomorrow , would that give any running issues or symptoms ? I will check the relay and actuator pipes too , tho these are not 50year old vac pipes, they were all renewed when car was restored , I know that was 12-13 years sgo but the car had only 5k on it and always garaged , all the vac pipes still look brand new just trying to give you as much background as possible. Thanks again
Mad4slalom
Well-known user
This is the cam fitted , I dont know how mild or wild it is.. I am looking at smoke / fog type vacuum leak testing machine on amazon which may help track down leak.
teamzr1
Supporting vendor
LSA at a Glance
Narrower LSA:- Moves torque to lower rpm
- Increases maximum torque
- Narrow powerband
- Increase chance of engine knock
- Increase cranking compression
- Idle vacuum and quality is reduced
- Valve overlap increases
- Decreases piston-to-valve clearance
- Raise torque to higher rpm
- Reduces maximum torque
- Broadens powerband
- Decrease chance of engine knock
- Decrease cranking compression
- Idle vacuum and quality is improved
- Valve overlap decreases
- Increases piston-to-valve clearance
teamzr1
Supporting vendor
What size engine your C3 have ?
Make sure it comes with, or you need to get smoker fluid, or I have used auto tranny fluid as it stinks
and can smell it first when leak is small and harder to first see the smoke
Smoke machines are fairly cheap, many below $100
Make sure it comes with, or you need to get smoker fluid, or I have used auto tranny fluid as it stinks
and can smell it first when leak is small and harder to first see the smoke
Smoke machines are fairly cheap, many below $100
Mad4slalom
Well-known user
350 4 bolt (pos truck block) 30 over, 356 cu inch, iron heads , flat top pistons, ali performer manifold and 650 holley double pumper. Engine builder quoted 355-365 bhp @6000 rpm
