| [GMCnet] idle question [message #68924] |
Wed, 30 December 2009 16:18  |
KB
Messages: 1262
Registered: September 2009
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Ok, I see the bit about setting the engine to 1100 rpm in Neutral
with the vac lines disconnected in order to check timing (8 degrees?)
But, what RPM should I see if it's just sitting in the driveway in Park
with the vac lines normally connected?? I've been searching manuals and
online, but haven't found anything definitive.
Can you tell I got a tachometer for Christmas? :-)
thanks,
Karen
1973 23' Patience Tester
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Karen
1975 26'
San Jose, CA
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| Re: [GMCnet] idle question [message #68930 is a reply to message #68924] |
Wed, 30 December 2009 17:20  |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Karen,
The reason you're not seeing any information on how to check the timing the
way you describe below is because you're NOT supposed to do it that way!
Follow the instructions as provided in the Maintenance Manual!
Before you check the timing I would suggest you remove the distributor cap
and make sure the mechanical advance is free then disconnect the hose that
goes into the vacuum advance assembly and suck on it to verify that it
moves.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of KB
Sent: Thursday, 31 December 2009 9:18 AM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] idle question
Ok, I see the bit about setting the engine to 1100 rpm in Neutral
with the vac lines disconnected in order to check timing (8 degrees?)
But, what RPM should I see if it's just sitting in the driveway in Park
with the vac lines normally connected?? I've been searching manuals and
online, but haven't found anything definitive.
Can you tell I got a tachometer for Christmas? :-)
thanks,
Karen
1973 23' Patience Tester
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] idle question [message #68956 is a reply to message #68924] |
Wed, 30 December 2009 19:11 |
KB
Messages: 1262
Registered: September 2009
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> The reason you're not seeing any information on how to check the timing the
> way you describe below is because you're NOT supposed to do it that way!
>
> Follow the instructions as provided in the Maintenance Manual!
I wasn't suggesting checking timing with the vac lines attached, etc.
Just wondering what a "normal" idle is supposed to be.
Fred answered it though -- 800-1000 rpm.
thanks,
Karen
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Karen
1975 26'
San Jose, CA
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| Re: [GMCnet] idle question [message #68970 is a reply to message #68956] |
Wed, 30 December 2009 20:07 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Karen,
Sorry, I mis-read your question.
However, if you set the idle to 800-1000 rpm you may have dieseling problems
and backfires that blow out the mufflers when you shut the engine off.
John Sharpe and I set the idle in Double Trouble at 600 rpm in Drive.
Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of KB
Sent: Thursday, 31 December 2009 12:12 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] idle question
> The reason you're not seeing any information on how to check the timing
the
> way you describe below is because you're NOT supposed to do it that way!
>
> Follow the instructions as provided in the Maintenance Manual!
I wasn't suggesting checking timing with the vac lines attached, etc.
Just wondering what a "normal" idle is supposed to be.
Fred answered it though -- 800-1000 rpm.
thanks,
Karen
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_______________________________________________
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] idle question [message #69039 is a reply to message #69026] |
Thu, 31 December 2009 07:26 |
Oldngray
Messages: 544
Registered: August 2009
Location: Punta Gorda Florida
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| Ken Burton wrote on Thu, 31 December 2009 04:54 |
I like mine slow so it is at 600 to 650.
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Ken,
Is that in Park/Neutral or Drive?
Richard MacDonald
Punta Gorda, Florida
Sold our TZE April 2015
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| Re: [GMCnet] idle question [message #69046 is a reply to message #69039] |
Thu, 31 December 2009 08:11 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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You know at that RPM it is about the same in neutral or drive. I like mine just above the speed where it would die when I put it in drive. Dick Paterson commented to me one time when he was in my coach about the engine speed. He asked if I liked it that way. Based on that question I know it is slower that normal spec.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] idle question [message #69055 is a reply to message #69050] |
Thu, 31 December 2009 08:25 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
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There are two idle adjustment stop screws. One on the choke and one on the carb base. If one does not do it, try the other one.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] idle question [message #69065 is a reply to message #69056] |
Thu, 31 December 2009 09:25 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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""Fred,
Until John Sharpe helped me lower the idle to 600-650 in drive the engine in
Double Trouble would diesel after I shut it down and backfire. I blew out
two sets of mufflers!""
Wow--that surprises me. I run mine at 900 in drive--seems to be happier off the line and also helps the AC a bit when it's 110 out here.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] idle question [message #69104 is a reply to message #68924] |
Thu, 31 December 2009 14:20 |
KB
Messages: 1262
Registered: September 2009
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To back that up, I finally found it in the manual. It's in the operating manual,
not the maintenance manual. For the '73, it's on page 82, and says 600 rpm
for slow idle, in Park and with assorted vac hoses disconnected. Fast idle is 1100 rpm.
>
> However, if you set the idle to 800-1000 rpm you may have dieseling problems
> and backfires that blow out the mufflers when you shut the engine off.
>
> John Sharpe and I set the idle in Double Trouble at 600 rpm in Drive.
>
> Regards,
> Rob Mueller
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Karen
1975 26'
San Jose, CA
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| Re: [GMCnet] idle question [message #69124 is a reply to message #69104] |
Thu, 31 December 2009 17:08 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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""To back that up, I finally found it in the manual. It's in the operating manual,
not the maintenance manual. For the '73, it's on page 82, and says 600 rpm
for slow idle, in Park and with assorted vac hoses disconnected. Fast idle is 1100 rpm""
That's the setting with the port to the charcoal cannister plugged--what does it run with the hose reconnected?
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] idle question [message #69126 is a reply to message #69055] |
Thu, 31 December 2009 17:47 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
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| Ken Burton wrote on Thu, 31 December 2009 08:25 |
There are two idle adjustment stop screws. One on the choke and one on the carb base. If one does not do it, try the other one.
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i've messed with the choke one too. if i get it to idle at 7 to 8oo on that one then it won't idle fast enough when cold and on the choke step. i'm about to do some work on the engine so i'll look at it again.
Fred V
'77 Royale RB 455
P'cola, Fl
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| Re: [GMCnet] idle question [message #69129 is a reply to message #69050] |
Thu, 31 December 2009 18:07 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| fred v wrote on Thu, 31 December 2009 07:19 |
i can't seem to get mine down that low without retarding the timing.
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Fred--on a different reply I asked about the hose to the charcoal cannister. the 600 rpm spec is with that hose plugged. It most likely will be higher with the hose connected. Also, without restarting the vacuum advance discussion, that 600 rpm spec is also with that hose plugged. Even if hooked to ported vacuum, you may get a slight amount of advance from that over and above the base 600 setting.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] idle question [message #69130 is a reply to message #69055] |
Thu, 31 December 2009 18:12 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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""There are two idle adjustment stop screws. One on the choke and one on the carb base. If one does not do it, try the other one. ""
That first step on the fast idle cam should get you around 1000 to 1100 rpm depending on preference--however, when warm, the screw should be off the fast idle cam--if not, your choke may not be fully open or the rod from the choke to the fast idle cam is misadjusted.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] idle question [message #69163 is a reply to message #69124] |
Thu, 31 December 2009 23:48 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Bob de Kruyff wrote on Thu, 31 December 2009 17:08 |
""To back that up, I finally found it in the manual. It's in the operating manual,
not the maintenance manual. For the '73, it's on page 82, and says 600 rpm
for slow idle, in Park and with assorted vac hoses disconnected. Fast idle is 1100 rpm""
That's the setting with the port to the charcoal cannister plugged--what does it run with the hose reconnected?
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Bob,
Why does the charcoal canister vacuum hose have any effect on idle setting?
I'll be honest. I never read the manual. I just set it where I wanted it (as slow as practical) and left it there.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] idle question [message #69174 is a reply to message #69163] |
Fri, 01 January 2010 07:36 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| Ken Burton wrote on Fri, 01 January 2010 00:48 |
| Bob de Kruyff wrote on Thu, 31 December 2009 17:08 |
""To back that up, I finally found it in the manual. It's in the operating manual, not the maintenance manual. For the '73, it's on page 82, and says 600 rpm for slow idle, in Park and with assorted vac hoses disconnected. Fast idle is 1100 rpm""
That's the setting with the port to the charcoal canister plugged--what does it run with the hose reconnected?
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Bob,
Why does the charcoal canister vacuum hose have any effect on idle setting?
I'll be honest. I never read the manual. I just set it where I wanted it (as slow as practical) and left it there.
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Ken,
It does not always, but it will often leak enough extra air/fuel in purge mode (not supposed to be at idle) to bump the speed of a nice tight motor. In short, it should not - but it often does - just like so many things.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] idle question [message #69199 is a reply to message #69174] |
Fri, 01 January 2010 10:39 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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""Ken,
It does not always, but it will often leak enough extra air/fuel in purge mode (not supposed to be at idle) to bump the speed of a nice tight motor. In short, it should not - but it often does - just like so many things.
Matt ""
I agree-I think some of us have experienced that. I find it interesting that GM recognized that even when new, since they consistantly mention that the cannister as well as the distributer vacuum advance (even though ported) need to be capped when setting idle.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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