fuel pressure dropping to nothing when going uphill - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-31-2008, 03:46 PM   #1
Jerkoff
Thread Starter
 
Join Date: Mar 2008
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
tpulliam79 is on a distinguished road
Default fuel pressure dropping to nothing when going uphill

I have new plugs and wires fuel filter pcv and air filter, when going about 45-60 mph uphill my car will cut out when accelerating, the fuel pressure is about 42 at startup then to about 50 uphill then it drops to almost nothing then kicks back up and so on. The scantool showed no misfires afterwards ? any ideas ? my fuel gauge is also way out of wack . this almost always happens at high speeds uphill and sometimes on the freeway from about 50-60 or so The boost gauge reads correctly and the sc runs smooth? I was thinking fuel pump but then woulnt I notice it more frequently and not just uphill and under heavy throttle?
tpulliam79 is offline   Reply With Quote
Old 03-31-2008, 03:54 PM   #2
Senior Member
Posts like a Turbo
 
Join Date: Jan 2008
Location: Memphis, TN
Posts: 281
Thanks: 0
Thanked 0 Times in 0 Posts
93RedSled-SSE is on a distinguished road
Default

Crappola... re-read that and saw you are losing pressure. Disregard my other questions if you see them.
There is a quick check for the FP Regulator. by disconnecting & plugging the vacuum line. Also, should be no fuel in that line. I'm sure everybody has a lot more to offer. Sorry about my earlier mess-up
93RedSled-SSE is offline   Reply With Quote
Old 03-31-2008, 03:57 PM   #3
Jerkoff
Thread Starter
 
Join Date: Mar 2008
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
tpulliam79 is on a distinguished road
Default

every once in a while when going 50-60 it will do it but more so uphill also except for the motor mount being bad and rubbing taking off quickly is pretty smooth and it idles pretty good
tpulliam79 is offline   Reply With Quote
Old 04-01-2008, 04:05 PM   #4
Jerkoff
Thread Starter
 
Join Date: Mar 2008
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
tpulliam79 is on a distinguished road
Default

well now its doing it alot more the rpms drop off as well as the fuel pressure almost like something is restricting the fuel flow, but it checks out at startup and idle if it was the pump going bad wouldnt it do it all of the time? would the fuel pressure regulator do this?
tpulliam79 is offline   Reply With Quote
Old 04-01-2008, 04:36 PM   #5
Senior Member
Posts like a Turbo
 
Join Date: Jan 2008
Location: Memphis, TN
Posts: 281
Thanks: 0
Thanked 0 Times in 0 Posts
93RedSled-SSE is on a distinguished road
Default

The FP regulator would be a good guess. Have you checked it at revs (in Park)? My FP will increase when I gas it. The regulator actually bleeds off pressure and feeds via a return line to the tank.
Maybe some of the experts will jump in; but I think you can disconnect & plug the vacuum line from the regulator and the pressure should go to max. The regulator can also leak fuel into the vacuum line (bad thing) (why I suggested doing the above check earlier).
My bad. I totally missed the SC fact.
93RedSled-SSE is offline   Reply With Quote
Old 04-01-2008, 06:18 PM   #6
Senior Member
Certified GM nut
 
Join Date: Oct 2005
Location: Western New York
Posts: 1,942
Thanks: 0
Thanked 0 Times in 0 Posts
Technical Ted is on a distinguished road
Default

Does it lose fuel pressure at a certain RPM or boost level. The Supercharged engines have a fuel control module that may be giving you trouble.
Technical Ted is offline   Reply With Quote
Old 04-01-2008, 06:36 PM   #7
Jerkoff
Thread Starter
 
Join Date: Mar 2008
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
tpulliam79 is on a distinguished road
Default

how do I test the fuel control module? I cleaned the grounds at the inner door ares and tested all my coils today all seemed good (pretty wet under the carpet though ) and after wards when coming home I went up a slight incline and it was doing it pretty badly? rpms dropped from like 2200 to almost nothing and back again?
tpulliam79 is offline   Reply With Quote
Old 04-01-2008, 10:03 PM   #8
Senior Member
Certified GM nut
 
Join Date: Oct 2005
Location: Western New York
Posts: 1,942
Thanks: 0
Thanked 0 Times in 0 Posts
Technical Ted is on a distinguished road
Default

I can't find any diagnostic info in the factory manual. You'd have to swap it out or bypass it to see if it'* bad.
Technical Ted is offline   Reply With Quote
Old 04-02-2008, 02:27 PM   #9
Jerkoff
Thread Starter
 
Join Date: Mar 2008
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
tpulliam79 is on a distinguished road
Default

how would I go about bypassing the fuel pump module? I have the fsm also but not a whole lot in there about the fuel pump control module.
tpulliam79 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Car died going uphill- Started one more time- Now it won't start. Brando_is_DTF 1992-1999 2 10-28-2008 02:08 PM
oil pressure dropping nicklikesmilk 1992-1999 9 11-27-2006 02:29 PM
oils pressure dropping chuckj15 1992-1999 12 10-16-2006 01:08 PM
95 Bonne hesitates going uphill Boog 1992-1999 21 08-01-2004 02:43 AM
noise/RPM change going uphill drjaymez 1992-1999 9 06-02-2004 05:17 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:00 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.