Thread: 3.5L V8 not engine braking smoothly

Hows your idle speed,
is it a little high when on LPG?

Thanks roverv8.

No it isn't high. I've played around with the idling a fair bit and the problem still occurs no matter what the idling is set at.

Edward

Originally Posted by I Love My Landy!

I've recently reconditioned the motor
I've got old ignition leads .... they only give a very slight misfire.

Does anybody know what could be causing this?

Edward

Time to buy your Gasmaster leads??
What is the condition of your Drivetrain??

Mike

Thanks mike 90 RR.

Yes probably. I was given the impression that i needed to use very high quality and very expensive ignition leads with my LPG motor (ie. magnecor, gasmaster), and this high price has prevented me from getting a set for a while, however i just called up a couple of well known Landy experts and they said to use cheaper leads and just replace them more often. If this is the case then i'll buy a set soon. Also i've had dodgy ignition leads on other cars that have caused a misfire under load, but never when engine braking.

The drivetrain is in pretty good condition. There is a little bit of wear on the axles but nothing out of the ordinary.

I don't think the problem is drivetrain related, it just feels as if the motor does not run right when engine braking which causes the whole car to lurch to and fro and causes the drivetrain to clunk about.

Edward

Originally Posted by I Love My Landy!

I don't think the problem is drivetrain related, it just feels as if the motor does not run right when engine braking which causes the whole car to lurch to and fro and causes the drivetrain to clunk about.

Interesting description of problem ...


BTW ... What model is your ride?? ... Are we talking carby with standard dizzy with points ... or EFI & electronic dizzy

1984 3.5L V8 County. Carby with original dizzy but with lumenition electronic system. The dizzy has had new weights put in specifically for LPG. The vacuum advance has been disconnected and i'm now running around 14 degrees advance timing.

Thanks!

Edward

Originally Posted by I Love My Landy!

The vacuum advance has been disconnected

Funny ... My first reaction to reading, the start of this thread, was to tell you to check the vacuum advance for working, and that it is hooked up to the proper inlet of the manifold

So your dizzy is modified ... So who knows what it's doing ....


Process of elimination .....
I would borrow a "known" second hand / ordinary Dizzy and give that a go .....



BTW ... If you recon'd the motor ... Did you do any mods to that also??


Mike

Apparently LPG likes to have a lot of initial advance with a low maximum advance, so the dizzy has been modified so that it has a maximum advance of only 28 degrees. Therefore I’m pretty sure that the vacuum advance is not necessary.

I’ve previously done some minor modifications to the motor, including a stage 2 camshaft, shaved the heads, port and polished the inlet manifold and did a few other little things. When I reconditioned the motor i basically just gave the motor a freshen up and replaced the stage 2 camshaft for a more standard (torquey) cam.

Edward