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Sun Nov 01, 2009 8:36 pm

I find that when i go from 4th gear to neutral to come to a stop, as i brake, my engine will die before i get to a complete stop. This happens randomly and seems to happen more when it is colder outside. Anyone know what this could be?

'69 bus 1600cc

Sun Nov 01, 2009 8:38 pm

Does this change after the engine has warmed up?

Do you always go straight from 4th to neutral.... how about if you downshift first?

Sun Nov 01, 2009 8:40 pm

it becomes less frequent but still occasionally happens. I also noticed that it happens alot when i am going down a hill to come to a stop

Sun Nov 01, 2009 8:41 pm

I just edited my answer to ask if you downshift... how about that? do you ever downshift?

Sun Nov 01, 2009 8:44 pm

no i never downshift. I always go straight from 4th to neutral. Should I start downshifting to a stop? I really don't know how to do it right.... :oops:

Sun Nov 01, 2009 8:46 pm

Quote: as i brake,

only when you brake? It doesn't do it if you take your foot off the gas and coast in neutral?

If it is only when you brake - verify that someone did not retrofit a brake booster on it. Next check your mixture screw and make sure it is adjusted correctly. Last if it sill does it, does your engine have any dashpots or throttle dampeners like they had in 1971? They are designed to hold the thottle off idle for a tad so the engine doesn't die. If your engine never had one, then I would also look at the float level in the carb.

Maybe you might also look at your wires near the engine. I had a sports car that would die on hard left hand turns. I finally found a wire grounding out on a sharp piece of metal.

Sun Nov 01, 2009 8:49 pm

i have only noticed it when i am braking

Sun Nov 01, 2009 8:54 pm

check your float level. If it is a foam float replace it. If it is a brass or hollow plastic float shake it to be sure it is empty.

I have seen water get into fuel and little globs of it sit in the bottom of the bowl, then when braking the water moves around and gets sucked in. If there are traces of water droplets in the bottom of the bowl, use a can of fuel dryer.

Do check your idle mixture first. Follow the procedure in Bentley.

Sun Nov 01, 2009 9:12 pm

Right. I'd check your idle adjustment first. See what Bentley says your RPM should be for that year/engine. If your idle is too low, it can die in situations like that, especially when you let the RPM drop rapidly from 4th gear driving all the way down to neutral.

That doesn't mean you should crank it up just to keep it running, tune it properly.

Then check your timing.

I'm assuming that is sort of peters out, not a drastic/sudden cut out, right?

Sun Nov 01, 2009 9:24 pm

To downshift, take your foot off the gas, press the brake and let the RPMs drop kinda low while in gear, press the clutch, move it up to 3rd, and ease the clutch back out.

I don't usually downshift to slow down though, unless I have to slow down really quickly like if some dick pulls out in front of me or something. It happens sometimes because my brakes are a little on the weak side right now. The way I've always looked at it is it's easier to replace brake pads and shoes than a clutch.

Sun Nov 01, 2009 9:41 pm

ok. the timing idea sounds good but the thing is.... my engine idles fine when sitting. its just slowing down when it tends to die out.

Sun Nov 01, 2009 10:15 pm

even if it idles fine doesn't mean it is adjusted correctly. When I was young I did a carb once that sounded great then we put a sniffer on it and it was way rich. Read Bentley.

Sun Nov 01, 2009 10:16 pm

ok yeah i really need one. all i have is the muir book right now...

Sun Nov 01, 2009 10:47 pm

you can find them used too pretty cheap. We bought a 1974 version with color wiring diagrams for like $15 a few months back. Check Ebay too.

Mon Nov 02, 2009 6:05 am

A brand new one was only $26.37 from Amazon 2 month ago.

Mon Nov 02, 2009 6:08 am

Please check the idle fuel cutoff solenoid.

Make sure it is wired and passes the "click" test.

Do you know how to do that? If not we can tell you how.

Also check the idle jet in the carb. The smallest bit of crud in there will pose idle problems.

If you don't know how to do that we can also helop you with that.

Mon Nov 02, 2009 7:33 am

Just a little hunch here, but I'm guessing that one of the smaller tubes running across the bottom of the intake manifold doesn't get too hot to touch after 30 seconds of running, and there is no hose or cable connected to your aircleaner preheat system.

Mon Nov 02, 2009 10:43 am

My 71' I just bought a week ago does the same thing. My bus does not have the preheater hose! Could this be the problem?

Mon Nov 02, 2009 10:58 am

spicolibus wrote: My 71' I just bought a week ago does the same thing. My bus does not have the preheater hose! Could this be the problem?

Could be, they run waaayyyy better with the preheat systems functioning.

Mon Nov 02, 2009 11:00 am

Another thing to fix, the list never ends...
thanks b-daddy