Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Buick > Park Avenue
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 09-09-2022, 05:43 PM   #1
ka9mgd
Registered User
 
ka9mgd's Avatar
 
Join Date: Aug 2007
Location: connersville, Indiana
Posts: 127
Thanks: 0
Thanked 0 Times in 0 Posts
vacuum specs-96 buick park avenue 3800

I m only getting 14 lbs on a vacuum gauge for a 3800 vin k engine. I have replaced the upper manifold and gasket and checked all vacuum hoses and also pinched off the vacuum hoses one at a time and the vacuum will not raise. There is a leak in the fuel tank filler neck or hose I noticed the last time I filled the gas tank. Will that leak be causing low vacuum since the tank will not pressurize? I am not getting any computer codes such as a p0441.
ka9mgd is offline   Reply With Quote
Old 09-09-2022, 07:10 PM   #2
maxwedge
A990 racer
 
Join Date: Mar 2002
Location: Chestertown, New York
Posts: 16,946
Thanks: 25
Thanked 369 Times in 363 Posts
Re: vacuum specs-96 buick park avenue 3800

No pending codes, how does the car run?
__________________
maxwedge is offline   Reply With Quote
Old 09-09-2022, 07:28 PM   #3
Blue Bowtie
Registered Offender
 
Blue Bowtie's Avatar
 
Join Date: Mar 2006
Location: Rural
Posts: 6,513
Thanks: 6
Thanked 341 Times in 336 Posts
Re: vacuum specs-96 buick park avenue 3800

I'm guessing that the original post was intended to read "14 inches (of mercury)" vacuum indicated on a gauge. 14 "pounds" would indicate an absolute pressure of less than 0.7 PSIA, which would translate to 28.494" Hg, which nothing but a liquid ring vacuum pump can accomplish reliably.

Factoring the elevation of Connertucky at 803' AMSL and the probable temperature and relative humidity of when the reading was made (early September), the deviations affect the "normal" vacuum indication which would be measured at 68°F, sea level (14.696 PSIA), and 35% R.H. Those adiabatic changes would indicate a 48.87% variation from "standard" numbers.

Incidentally, there are quite a few fairly astute people in Connersville (Howden-Roots) who can explain that in great detail.

The other factor is the engine RPM when the measurement was taken. That is a critical item, and missing from the data.
__________________
Permanent seat assignment on the Group W bench...
Automotive Forums Survival Guide
Blue Bowtie is offline   Reply With Quote
Old 09-09-2022, 07:58 PM   #4
ka9mgd
Registered User
Thread starter
 
ka9mgd's Avatar
 
Join Date: Aug 2007
Location: connersville, Indiana
Posts: 127
Thanks: 0
Thanked 0 Times in 0 Posts
Re: vacuum specs-96 buick park avenue 3800

Yes I meant 14 inches at idle. The car is running fine. It was hesitating some on slight acceleration going up a hill before cleaning the throttle body and no computer codes are present.
ka9mgd is offline   Reply With Quote
Old 09-09-2022, 08:52 PM   #5
Blue Bowtie
Registered Offender
 
Blue Bowtie's Avatar
 
Join Date: Mar 2006
Location: Rural
Posts: 6,513
Thanks: 6
Thanked 341 Times in 336 Posts
Re: vacuum specs-96 buick park avenue 3800

Some of the Series II Buick V-6 SFI engines had a TSB applicable to this phenomenon.

Since the PCM does not monitor fuel pressure, it may also be beneficial to measure that. Marginally weak secondary ignition components can also be involved. Excessively wide spark plug gaps, failing/high resistance plug wires, and coil secondary breakdown can create this kind of situation.

There is also potentially torque converter clutch lag, low primary voltage, and other causes described in the service bulletin.
__________________
Permanent seat assignment on the Group W bench...
Automotive Forums Survival Guide
Blue Bowtie is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Buick > Park Avenue

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 01:48 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts