Horrible Mileage - FIXED! 100%

chitwnvw · Post by **chitwnvw** » Mon Jun 18, 2007 9:12 pm

C'mon, Sluggo. Don't leave a guy hangin'.

Post by **Sluggo** » Tue Jun 19, 2007 11:27 am

chitwnvw wrote:C'mon, Sluggo. Don't leave a guy hangin'.

Just got back.

You adjust the accelerator pump by turning the nut on the rod underneath and in between the two barrels of the carb. Crank them in till they are all the way tight without opening the idle stops. Then bring out them equally on both carbs in 1/2 turns increments. Do this until you have a smooth response across the throttle range.

Post by **Sluggo** » Tue Jun 19, 2007 12:00 pm

Extended my trip slightly. Bus performed wonderfully.

Throughout the trip I averaged 19.88 MPG! Best mileage was 22.17 MPG traveling on flat land with very little head wind floating around 60-65 MPH. Worst was 18.93 MPG with lots of strong winds and lots of uphill climbs.

Head and oil temps were great. Climbing uphill with tons of wind the highest the temps reached were 400 head and 235 oil. Averaged 350 on the heads and 215 oil.

Loads of power!!! The Bus loves 65-70 MPH. Temps will hover at 360 and 215 with easy acceleration and a very smooth ride.

Didn't burn a drop of oil.

I LOVE MY BUS AGAIN!!!!!

Jetting that worked best:

36 Weber IDFs
135 Main
200 A/C
55 Idle
F-7 E-Tube
33 Pump Jet (7 & 1/2 full turns out)

A road trip is the best way to fine tune your carbs. I was able to pull over and swap out jets to see what performed best where. Things would seem great, then I'd hit a hill and transition would be harder, extended the accelerator pump spring and it took care of it. Cruising would be fine then I would lean out and hit a flat spot at high end acceleration, bumped up the mains slightly and it worked. I really think a road trip with hills is the key. You can see how your carbs react in every situation and adjust accordingly on the fly.

[albumimg]933[/albumimg]

Post by **Amskeptic** » Thu Jun 21, 2007 1:52 pm

Sluggo wrote: The Bus loves 65-70 MPH.
Didn't burn a drop of oil.
I LOVE MY BUS AGAIN!!!!!

I look forward to driving it, after our rather gentrified toodling about your neighborhood last summer when I was ranting about the smoothness and sorrowfully experiencing the laggardness.
Colin

Post by **Sluggo** » Thu Jun 21, 2007 6:28 pm

Amskeptic wrote:
Sluggo wrote: The Bus loves 65-70 MPH.
Didn't burn a drop of oil.
I LOVE MY BUS AGAIN!!!!!
I look forward to driving it, after our rather gentrified toodling about your neighborhood last summer when I was ranting about the smoothness and sorrowfully experiencing the laggardness.
Colin

I've been easily accelerating up the Hollywood Hills all week. It's truly a pleasure to drive now. I highly anticipate your arrival when you shall lay your healing hands upon my engine and give it that one little tweek that will make it even better.

I have been having one problem. When I first start her up the air/fuel ratio monitor reads lean (this is after the sender has warmed up properly) and she idles rough. Once the engine fully warms up my readings are fine (a little bouncy but fine) and she idles smooth. Then it will occasionally lean out again for no reason. This is all only at idle. Acceleration is smooth and easy and my readings are always at 13 (which is where my engine seems to run best).

Mileage is still good. But driving a few short 5 & 10 minute trips a day makes for very bad mileage. I get between 18.5 & 22 MPG on the freeway depending on hills, winds & traffic. I get between 16.5 & 18 MGP on the streets. But that's only if I actually drive (more than a few minutes spent mostly waiting at lights). With the short little trips I do it's getting about 12 MPG. The past few days I've just been driving around for half an hour before I go to my other building just to legitimize mileage and keep the engine happy.

chitwnvw · Post by **chitwnvw** » Thu Jun 21, 2007 7:26 pm

That seems pretty normal, Sluggo. I think if your biggest problem is what your gauges read, you're doing pretty good.

DurocShark · Post by **DurocShark** » Fri Jun 22, 2007 5:36 am

Sounds like you still have some idle mixture issues.

Post by **Sluggo** » Mon Jun 25, 2007 12:33 pm

DurocShark wrote:Sounds like you still have some idle mixture issues.

That's my feeling. I checked my plugs yesterday and they were a little light (indicating a lean mixture). I upped the mixture screws slightly and it did improve. But I think I'm just covering up an intermittent vac leak.

dingo · Post by **dingo** » Mon Jun 25, 2007 12:46 pm

are you using an 02 sensor for the fuel/air ratio? and if so, where did you locate it in the exhaust ?

chitwnvw · Post by **chitwnvw** » Mon Jun 25, 2007 2:55 pm

dingo wrote:are you using an 02 sensor for the fuel/air ratio? and if so, where did you locate it in the exhaust ?

I thought that is was nigh on to impossible to get truly accurate readings unless you ran 4 seperate sensors, being that if you used one it would be pretty far downstream...

Post by **Sluggo** » Mon Jun 25, 2007 3:03 pm

dingo wrote:are you using an 02 sensor for the fuel/air ratio? and if so, where did you locate it in the exhaust ?

I'm using an Edelbrock Air/Fuel Ratio Monitor. It has a heater and gives accurate readings within a few minutes. The best recommended spot I could find was right next to the tail pipe flange.

DurocShark · Post by **DurocShark** » Mon Jun 25, 2007 3:27 pm

As long as the sensor has an internal heater, it can be placed pretty much anywhere.

bottomend · Post by **bottomend** » Tue Jun 26, 2007 9:24 pm

Hey Sluggo, I looked at the " travel" pics in your gallery. Nice Photoshop job with the Golden Gate Bridge. Except for getting the shadows backwards, it looks pretty convincing. So... when do you think you'll get the bus on the road for real?

chitwnvw · Post by **chitwnvw** » Wed Jun 27, 2007 2:11 pm

Now if you have one sensor at the end of the line, and 4 carb barrels feeding 4 cylinders, how do you determine what's going on in each cylinder?

Post by **Sluggo** » Wed Jun 27, 2007 3:06 pm

chitwnvw wrote:Now if you have one sensor at the end of the line, and 4 carb barrels feeding 4 cylinders, how do you determine what's going on in each cylinder?

You don't. At least not with one air fuel ratio monitor. If you wanted a reading for each barrel you'd need 4 monitors with four senders welded into each exhaust manifold. About $500 for all that not including having the bungs welded in for the sender.

Itinerant Air-Cooled

Itinerant Air-Cooled

Horrible Mileage - FIXED! 100%