Question of the Day

[bravekozak]

New question concerning barometric pressure (BP) switch on carbureted Festivas. The shop manual doesn't say much. The ECA has a built in BP sensor. When pressure decreases because of high altitude, the BP switch is switched on. The Blue/orange wire runs from the ECA to both the BP switch and the distributor. The question is how does the BP switch affect the distributor. Can I just get rid of it?

Actually, what I want to do is not cut the wiring harness open to add a blue/white wire to run back to the former EFE heater relay that I am now using for A/C idle up. I wouldn't mind using that BP switch connector, which just happens to conveniently be right beside the A/C switch connector.

The BP switch is not a solenoid. I thought it had the diaphram in it to detect atmospheric pressure variation. I thought when it closed, it grounded and prevented the ECA signal from reaching the distributor. Can someone test this theory? I need a volunteer with a carby to disconnect the blue/orange wire (single connector) going into the distributor module and check the voltage.

I wonder if BP sensors are like MAP sensors and provide a variable voltage to the distributor module?

Many thanks.

[Spike]

^^I have no idea!

MPG question. I've had this for a while. My daily commute has been hills hills hills. Is it better to stay in 5th gear and floor it at all times, or to stay in 4th with 1/2-3/4 throttle? In the Sprint, 55MPH is 3100 in 4th, 2650 in 5th.

I seem to get the same MPG either way.. but it now drives me a bit more nuts since we got the '89 LX. It'll hold 55-60 [uphill] if you completely floor it. The Sprint would lose speed down to about 51 [by the crest of the hill].

-Joe

[getnpsi]

Why Festiva? BECAUSE OBAMA.

[bravekozak]

I found a partial answer to my question in post #16.
At sea level the voltage is high 10 - 12 V.
I presume if it is disconnected the voltage will drop to zero and the distributor will think it's at the top of Mount Everest. If the module perceives a lean condition (less air, less gas), I presume it will try to compensate for it.
I would still appreciate if someone could disconnect the single blue/orange barometric wire at the distributor and tell me how it runs.

At high altitudes you can run more advance. At 4500 feet above sea level we could get away with 40 degrees total (initial + mech.) but that will detonate

at sea level

[zoom zoom]

Which one do you think would look better on the dash of my Festiva?
This one? or this one?

Second one ofc

^^I have no idea!

MPG question. I've had this for a while. My daily commute has been hills hills hills. Is it better to stay in 5th gear and floor it at all times, or to stay in 4th with 1/2-3/4 throttle? In the Sprint, 55MPH is 3100 in 4th, 2650 in 5th.

I seem to get the same MPG either way.. but it now drives me a bit more nuts since we got the '89 LX. It'll hold 55-60 [uphill] if you completely floor it. The Sprint would lose speed down to about 51 [by the crest of the hill].

-Joe

B6 swap and stay at normal cruise petal height in 5th. 3rd or 4th downshift and floor it depending on how fast you want to pass going uphill.

[Spike]

...curse you.

:p

[bravekozak]

I have two transaxles. They have different shaft diameters. Is one from an Aspire?
If so, how can I tell the difference?

[F3BZ]

I don't know the answer brave but thanks for pointing out the different boots in the answer to my PS question. I never would have known about it being different until I got around to converting my GL to the PS setup. Lucki. That 4Green still had the PS version available and I was able to add that to my pile of PS parts.


"



An




'

[bravekozak]

The boys at Z&A Rebuilders told me to bring them both in. They said they will be able to figure it out for me. That's all they do. Rebuild transaxles. I will post the answer when I find out.

[zoe60]

I've got one. On an Aspire swapped Festy will the brakes ever wear out? After about 30,000 I had to free up the parking brake/adjuster lever again and the rear shoes look like brand new! I swear it's been years since I did the swap. I wonder if the fluid would stay in parked sideways on a steep enough hill? lol and I like the hula girl better than Obama any day!

[mikeyjd]

^^I have no idea!

MPG question. I've had this for a while. My daily commute has been hills hills hills. Is it better to stay in 5th gear and floor it at all times, or to stay in 4th with 1/2-3/4 throttle? In the Sprint, 55MPH is 3100 in 4th, 2650 in 5th.

I seem to get the same MPG either way.. but it now drives me a bit more nuts since we got the '89 LX. It'll hold 55-60 [uphill] if you completely floor it. The Sprint would lose speed down to about 51 [by the crest of the hill].

-Joe

This has been tested quite a bit on ecomodder. The conclusion to the tests on vehicle's with manual transmissions, was that it's best to take hills in the highest gear at the slowest speed possible without having to downshift. It's more efficient to accelerate going uphill and coast down the hill in neutral, than it is to accelerate down the hill and lose your speed going up the hill. It can vary a bit between vehicle's to what extent this is true, it has allot to do with each vehicles Brake Specific Fuel Consumption and Torque Curve maps. A general rule of thumb is 75-85% engine load is going to be your most efficient operating range.

[Spike]

Thanks! I shall continue to stay in 5th and drive the guy behind me nuts.

-Joe

I'm saving fuel, it's for the plannnnneeeeettt! :highly_amused:

[bravekozak]

The washers for the sway bar to control arm bushings are dished. Which way should the dish (curved part) face? Toward or away from the bushing?

[fastivaca]

The washers for the sway bar to control arm bushings are dished. Which way should the dish (curved part) face? Toward or away from the bushing?

Toward. The "dish" is on the outside.

Sent from somewhere west of here via Tapatalk!

[william]

how in the heck do you get the boot off or up enough to get to the stearing u joint .
i went to change my inertie rods and foud out there still good.
and that the clanking is coming from the u joint under the boot.
i guess i didn't get it tight when i changed out the rack about 15xxx ago.
I'm glad its not the tierod ends that i just changed but that boot is driving me crazy.