Advice on tuning for high altitude please?
- Thread starter richard guthart
- Start date
Post the information on the vacuum boosters please.
>Richard.........You may find out that at your altitude, the somewhat
>marginal brakes become more marginal because of lack of vacuum. If you or
>any of the other troops want, I'll give you a listing of older GMC vehicles
>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>ten dollars in the local junkyard. New, they're over $400. Not only will
>they compensate for altitude, but they also keep you from going
>Wheeeeeeeeeeee on a long downhill if your engine quits..... Jim Davis
>-----Original Message-----
>From: Richard Guthart
>To: gmcmotorhome
>Date: Tuesday, July 14, 1998 8:18 PM
>Subject: GMC: Advice on tuning for high altitude please?
>
>
>>Greetings, GMCer's.
>>
>>I'm new to this list. Just purchased a '77 Transmode in Omaha and drove it
>>to my home in Fort Collins, Colorado and am wondering how to tune it for
>>best performance at this altitude - 5,000 feet above sea level.
>>
>>Is it just a matter of installing smaller jets in the QuadraJet and
>>advancing the timing a few degrees, or are there other tweaks that will
>>help? If smaller jets are called for what size would you recommend?
>>
>>My Transmode is an early '77 with the 455 engine, 56,000 miles on it.
>>
>>I'm hoping some of my fellow Coloradoans who are regulars on this list (Hi,
>>Rick Staples in Louisville) would be able to steer me in the right
>direction
>>before I go to the emissions test station.
>>
>>Thanks,
>>
>>Richard Guthart (rguthart)
>>
>>'77 Birchaven
>>
>>
>>
>
>
>
>Richard.........You may find out that at your altitude, the somewhat
>marginal brakes become more marginal because of lack of vacuum. If you or
>any of the other troops want, I'll give you a listing of older GMC vehicles
>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>ten dollars in the local junkyard. New, they're over $400. Not only will
>they compensate for altitude, but they also keep you from going
>Wheeeeeeeeeeee on a long downhill if your engine quits..... Jim Davis
>-----Original Message-----
>From: Richard Guthart
>To: gmcmotorhome
>Date: Tuesday, July 14, 1998 8:18 PM
>Subject: GMC: Advice on tuning for high altitude please?
>
>
>>Greetings, GMCer's.
>>
>>I'm new to this list. Just purchased a '77 Transmode in Omaha and drove it
>>to my home in Fort Collins, Colorado and am wondering how to tune it for
>>best performance at this altitude - 5,000 feet above sea level.
>>
>>Is it just a matter of installing smaller jets in the QuadraJet and
>>advancing the timing a few degrees, or are there other tweaks that will
>>help? If smaller jets are called for what size would you recommend?
>>
>>My Transmode is an early '77 with the 455 engine, 56,000 miles on it.
>>
>>I'm hoping some of my fellow Coloradoans who are regulars on this list (Hi,
>>Rick Staples in Louisville) would be able to steer me in the right
>direction
>>before I go to the emissions test station.
>>
>>Thanks,
>>
>>Richard Guthart (rguthart)
>>
>>'77 Birchaven
>>
>>
>>
>
>
>
Yes, I'd like the vac pmp list and wiring diagram if it isn't too much
trouble. Thanks in advance. Sam Pickens 770-329-1592.
- -----Original Message-----
From: RickStapls
To: gmcmotorhome
Date: Thursday, July 16, 1998 2:39 AM
Subject: Re: GMC: Advice on tuning for high altitude please?
>>If you or
>>any of the other troops want, I'll give you a listing of older GMC
vehicles
>>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>>ten dollars in the local junkyard.
>
>Jim,
> I picked up one of these pumps in my local boneyard (paid $25, that's
>Boulder for you) but I need a wiring diagram/info to hook it up correctly.
I
>got all the associated vacuum fittings including a separate vacuum switch
that
>was mounted near the booster diaphragm. (82 J2000). Investigating my
>treasure when I got it home, I found a built-in vacuum switch and a circuit
>board with transistors etc mounted on the pump itself. Further clouding
>things, the pump connector has a 4-wire connector with only 3-wires used.
>Not wanting to smoke any semiconductors, I put it on the back burner for
now.
> Question: do you or anyone else here have complete wiring info/diagrams
for
>this setup? Maybe Patrick could post them on his site? TIA.
>
>Rick Staples
trouble. Thanks in advance. Sam Pickens 770-329-1592.
- -----Original Message-----
From: RickStapls
To: gmcmotorhome
Date: Thursday, July 16, 1998 2:39 AM
Subject: Re: GMC: Advice on tuning for high altitude please?
>>If you or
>>any of the other troops want, I'll give you a listing of older GMC
vehicles
>>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>>ten dollars in the local junkyard.
>
>Jim,
> I picked up one of these pumps in my local boneyard (paid $25, that's
>Boulder for you) but I need a wiring diagram/info to hook it up correctly.
I
>got all the associated vacuum fittings including a separate vacuum switch
that
>was mounted near the booster diaphragm. (82 J2000). Investigating my
>treasure when I got it home, I found a built-in vacuum switch and a circuit
>board with transistors etc mounted on the pump itself. Further clouding
>things, the pump connector has a 4-wire connector with only 3-wires used.
>Not wanting to smoke any semiconductors, I put it on the back burner for
now.
> Question: do you or anyone else here have complete wiring info/diagrams
for
>this setup? Maybe Patrick could post them on his site? TIA.
>
>Rick Staples
>
> Question: do you or anyone else here have complete wiring
> info/diagrams for this setup? Maybe Patrick could post them on
> his site? TIA.
I'd be glad to, along with pictures of an installation in a GMC. Just
email the jpegs or snail mail the hardcopies and I'll scan and return
them.
Patrick
- --
Patrick Flowers
Mailto
atri63
The GMC Motorhome Page
http://www.gmcmotorhome.com
> Question: do you or anyone else here have complete wiring
> info/diagrams for this setup? Maybe Patrick could post them on
> his site? TIA.
I'd be glad to, along with pictures of an installation in a GMC. Just
email the jpegs or snail mail the hardcopies and I'll scan and return
them.
Patrick
- --
Patrick Flowers
Mailto
atri63The GMC Motorhome Page
http://www.gmcmotorhome.com
I have the orig maint manual w/all dwgs to include wiring. Just exactly what
wiring are you refering? They're large in size; my scaner won't scan. Could
mail. Advise. picksam PH:7703291592 or POB 23494; Macon,
GA 31212-3494
- -----Original Message-----
From: Patrick Flowers
To: gmcmotorhome
Date: Thursday, July 16, 1998 7:46 AM
Subject: Re: GMC: Advice on tuning for high altitude please?
>>
>> Question: do you or anyone else here have complete wiring
>> info/diagrams for this setup? Maybe Patrick could post them on
>> his site? TIA.
>
>I'd be glad to, along with pictures of an installation in a GMC. Just
>email the jpegs or snail mail the hardcopies and I'll scan and return
>them.
>
>Patrick
>--
>Patrick Flowers
>Mailtoatri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
wiring are you refering? They're large in size; my scaner won't scan. Could
mail. Advise. picksam PH:7703291592 or POB 23494; Macon,
GA 31212-3494
- -----Original Message-----
From: Patrick Flowers
To: gmcmotorhome
Date: Thursday, July 16, 1998 7:46 AM
Subject: Re: GMC: Advice on tuning for high altitude please?
>>
>> Question: do you or anyone else here have complete wiring
>> info/diagrams for this setup? Maybe Patrick could post them on
>> his site? TIA.
>
>I'd be glad to, along with pictures of an installation in a GMC. Just
>email the jpegs or snail mail the hardcopies and I'll scan and return
>them.
>
>Patrick
>--
>Patrick Flowers
>Mailto
atri63>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>
> I have the orig maint manual w/all dwgs to include wiring. Just
> exactly what wiring are you refering? They're large in size; my
> scaner won't scan. Could mail. Advise. picksam
> PH:7703291592 or POB 23494; Macon, GA 31212-3494
>
> >>
> >> Question: do you or anyone else here have complete wiring
> >> info/diagrams for this setup? Maybe Patrick could post them on
> >> his site? TIA.
Sam,
It's not the GMC manual he's referring to. This is an auxilliary vacuum
pump off another vehicle.
Patrick
- --
Patrick Flowers
Mailtoatri63
The GMC Motorhome Page
http://www.gmcmotorhome.com
> I have the orig maint manual w/all dwgs to include wiring. Just
> exactly what wiring are you refering? They're large in size; my
> scaner won't scan. Could mail. Advise. picksam
> PH:7703291592 or POB 23494; Macon, GA 31212-3494
>
> >>
> >> Question: do you or anyone else here have complete wiring
> >> info/diagrams for this setup? Maybe Patrick could post them on
> >> his site? TIA.
Sam,
It's not the GMC manual he's referring to. This is an auxilliary vacuum
pump off another vehicle.
Patrick
- --
Patrick Flowers
Mailto
atri63The GMC Motorhome Page
http://www.gmcmotorhome.com
I got the following wiring info from an electric car list I am on. Hope it
helps you with your vacuum pump.
>Here is how I have my GM pump wired on my EV.
>
>Connection A (Red wire) battery positive, 12 volts+ through a fuse.
>Connection B (Black with white stripe) ignition positive, 12 volts+
>Connection C (plugged) not used (not used in factory system either)
>Connection D (Black wire) ground, 12 volts-
>
>The pump is powered via the A connection, but will only run if it
>receives power from the ignition switch on the B connection.
Dave Mumert
dmumert
- -----Original Message-----
From: owner-gmcmotorhome
[mailto
wner-gmcmotorhome]On Behalf Of
RickStapls
Sent: Thursday, July 16, 1998 12:39 AM
To: gmcmotorhome
Subject: Re: GMC: Advice on tuning for high altitude please?
>If you or
>any of the other troops want, I'll give you a listing of older GMC vehicles
>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>ten dollars in the local junkyard.
Jim,
I picked up one of these pumps in my local boneyard (paid $25, that's
Boulder for you) but I need a wiring diagram/info to hook it up correctly.
I
got all the associated vacuum fittings including a separate vacuum switch
that
was mounted near the booster diaphragm. (82 J2000). Investigating my
treasure when I got it home, I found a built-in vacuum switch and a circuit
board with transistors etc mounted on the pump itself. Further clouding
things, the pump connector has a 4-wire connector with only 3-wires used.
Not wanting to smoke any semiconductors, I put it on the back burner for
now.
Question: do you or anyone else here have complete wiring info/diagrams
for
this setup? Maybe Patrick could post them on his site? TIA.
Rick Staples
helps you with your vacuum pump.
>Here is how I have my GM pump wired on my EV.
>
>Connection A (Red wire) battery positive, 12 volts+ through a fuse.
>Connection B (Black with white stripe) ignition positive, 12 volts+
>Connection C (plugged) not used (not used in factory system either)
>Connection D (Black wire) ground, 12 volts-
>
>The pump is powered via the A connection, but will only run if it
>receives power from the ignition switch on the B connection.
Dave Mumert
dmumert
- -----Original Message-----
From: owner-gmcmotorhome
[mailto
wner-gmcmotorhome]On Behalf OfRickStapls
Sent: Thursday, July 16, 1998 12:39 AM
To: gmcmotorhome
Subject: Re: GMC: Advice on tuning for high altitude please?
>If you or
>any of the other troops want, I'll give you a listing of older GMC vehicles
>that have the auxiliary vacuum pump on them. I purchased mine for a whole
>ten dollars in the local junkyard.
Jim,
I picked up one of these pumps in my local boneyard (paid $25, that's
Boulder for you) but I need a wiring diagram/info to hook it up correctly.
I
got all the associated vacuum fittings including a separate vacuum switch
that
was mounted near the booster diaphragm. (82 J2000). Investigating my
treasure when I got it home, I found a built-in vacuum switch and a circuit
board with transistors etc mounted on the pump itself. Further clouding
things, the pump connector has a 4-wire connector with only 3-wires used.
Not wanting to smoke any semiconductors, I put it on the back burner for
now.
Question: do you or anyone else here have complete wiring info/diagrams
for
this setup? Maybe Patrick could post them on his site? TIA.
Rick Staples
