mysterious lack of power and bogging - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-11-2012, 05:24 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
mysterious lack of power and bogging

i posted another thread about amonth ago that kinda went off topic into return lines for fuel pumps (which i needed) but my problem still persists and has gotten very bad. i have little to no power, i can barely accelerate and it takes a stretch of about three to four miles to reach highway speeds. i have no secondaries, the moment i get into them the engine boggs heavily and is now dying. if i snap the throttle at an idle it almost dies also. its a chevy 305 with a factory qjet from an 85 305. my engine is a tbi ho bottom end with 1st gen heads and a factory cast intake and like previously stated a fatory 85 qjet. i pulled some plugs today and they all look like normal wear, a slight orange/tan color on the insulator and the ground strap with some electrode wear but barely noticable. i changed all fuel filters and air filter and has a brand new fuel pump. im about pulling my hair out guys. i dont mean to single anyone out but cobalt 327 and spinn have been very helpful i hope you two can come to my rescue again. thanx in avance guys, and dont be afraid to ask any question i wont take offence to anything because obviously im missing something here

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-11-2012, 05:55 PM
S10 Racer's Avatar
http://www.warsprints.com
 

Last journal entry: W.A.R. (Wingless Auto Racing) Sprint Car Racing
Last photo:
Join Date: Nov 2007
Location: At The Dirt Tracks
Age: 55
Posts: 1,881
Wiki Edits: 0

Thanks: 3
Thanked 59 Times in 54 Posts
Are you sure it's fuel related and not timing related? If you think it's a carb issue, try and find another carb (maybe borrow one just for testing), replace it and see if it helps. Are you running a fuel pressure regualtor and have you tested the fuel pressure to the carb?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-11-2012, 05:55 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 596
Wiki Edits: 0

Thanks: 0
Thanked 26 Times in 25 Posts
Weren't the '85 Q jets electronic and had a computer controlled solenoid for air/fuel ratio? I know my '85 Monte did. Are you using a computer?
ssmonty
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-11-2012, 06:01 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'm almost positive this isn't timing, this problem just happened out of nowhere the day after I swapped my fuel pump. And no I'm not using a regulator but my pump only puts out 7psi max and I also thought the 85 qjets were computer controlled but theres nothing on this one even remotely electronic looking
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-11-2012, 06:56 PM
S10 Racer's Avatar
http://www.warsprints.com
 

Last journal entry: W.A.R. (Wingless Auto Racing) Sprint Car Racing
Last photo:
Join Date: Nov 2007
Location: At The Dirt Tracks
Age: 55
Posts: 1,881
Wiki Edits: 0

Thanks: 3
Thanked 59 Times in 54 Posts
Quote:
Originally Posted by hauss667
I'm almost positive this isn't timing, this problem just happened out of nowhere the day after I swapped my fuel pump. And no I'm not using a regulator but my pump only puts out 7psi max and I also thought the 85 qjets were computer controlled but theres nothing on this one even remotely electronic looking
Mechanic pump? Have you verified that the pressure is 7psi or going off from the specs for that pump?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-11-2012, 07:16 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'm going off the specs for the pump and no its an airtex electronic pump as my bottom end is from a tbi motor and doesn't have the cam lobe to run a mechanical
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-11-2012, 07:30 PM
S10 Racer's Avatar
http://www.warsprints.com
 

Last journal entry: W.A.R. (Wingless Auto Racing) Sprint Car Racing
Last photo:
Join Date: Nov 2007
Location: At The Dirt Tracks
Age: 55
Posts: 1,881
Wiki Edits: 0

Thanks: 3
Thanked 59 Times in 54 Posts
Quote:
Originally Posted by hauss667
I'm going off the specs for the pump and no its an airtex electronic pump as my bottom end is from a tbi motor and doesn't have the cam lobe to run a mechanical
I have heard the Airtex pump is not that great and have had some problems but I can't confirm it. My thinking is if things started after changing the pump, try replacing it and see if it helps. I know thats asking for you to buy another pump but my common sense says that is where I would start since the problem started after replacing it the first time. If it ran good before the pump change most likely the pump is the problem. Just my .02
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 06-11-2012, 08:02 PM
Member
 
Join Date: Aug 2003
Location: California
Posts: 903
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
hauss667,

Check the exhaust system. If the engine runs good with no load but bogs and takes two miles to get up to freeway speed says restricted exhaust. Put a vacuum gauge on the engine and rev it up to 2000 RPM and hold that RPM steady. Watch the vacuum gauge. Once it gets up to speed the vacuum should have a reading of 18 inches of vacuum maybe a little more. But if it falls below that and continues to fall it means the exhaust is restricted.

Scholman
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 06-11-2012, 08:16 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by scholman
hauss667,

Check the exhaust system. If the engine runs good with no load but bogs and takes two miles to get up to freeway speed says restricted exhaust. Put a vacuum gauge on the engine and rev it up to 2000 RPM and hold that RPM steady. Watch the vacuum gauge. Once it gets up to speed the vacuum should have a reading of 18 inches of vacuum maybe a little more. But if it falls below that and continues to fall it means the exhaust is restricted.

Scholman
I set my timing off manifold vacuum, so when I went to check timing I also did this thinking maybe I had a clogged cat because I recently developed a horrendous exhaust leak st the collector, but it raises to almost 20 and holds steady
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 06-11-2012, 08:19 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by S10 Racer
I have heard the Airtex pump is not that great and have had some problems but I can't confirm it. My thinking is if things started after changing the pump, try replacing it and see if it helps. I know thats asking for you to buy another pump but my common sense says that is where I would start since the problem started after replacing it the first time. If it ran good before the pump change most likely the pump is the problem. Just my .02
I will try this if all else fails, but I'm so tight on money I can't spare an extra 50 bucks, a midst of mine is going to come over tomorrow and help me tear apart an old edlebrock and throw it on and see if it helps
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 06-11-2012, 08:27 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
I recall you saying it ran bad after you welded a hangar. Go back and LOOK at the areas where the work was done. Something got fouled up during the repair- a plug wire pulled off or damaged, vacuum line off (maybe the tranny modulator), something. And you need to recheck the timing. Or just give the distributor a turn CCW to advance the timing some to see if it helps. That will also tell you if the clamp is loose enough for the distributor to get turned accidentally.

Recheck the firing order- it's very easy to get #5 and #7 crossed because they are next to each other in the firing order and next to each other on the distributor cap and at the plugs on the driver side head.

Did you clean the carb w/carb spray?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 06-11-2012, 10:37 PM
hauss667's Avatar
Knuckle color never lies
 

Last journal entry: gettin with the times
Last photo:
Join Date: Jan 2012
Location: hillsboro, or
Age: 23
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by cobalt327
I recall you saying it ran bad after you welded a hangar. Go back and LOOK at the areas where the work was done. Something got fouled up during the repair- a plug wire pulled off or damaged, vacuum line off (maybe the tranny modulator), something. And you need to recheck the timing. Or just give the distributor a turn CCW to advance the timing some to see if it helps. That will also tell you if the clamp is loose enough for the distributor to get turned accidentally.

Recheck the firing order- it's very easy to get #5 and #7 crossed because they are next to each other in the firing order and next to each other on the distributor cap and at the plugs on the driver side head.

Did you clean the carb w/carb spray?
I actually re did everything today, I pulled all my plugs to check the condition lean or fouled and re did my firing order with new plug wires, yes I used some carb spray on the carb and checked my vacuum lines while I had the air cleaner off. The hanger I re welded was back behind the gas tank, nothing to hurt there. And I tried turning my distributor cw and ccw to no avail... Everything is pointing to either the fuel pump or internal carb...
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lack of power! weirdbeard Engine 5 04-01-2006 04:04 PM
400 CI lack of power 77chevy400 Engine 6 12-16-2005 11:15 PM
Mysterious Power Problems riesman20 Electrical 3 12-12-2005 09:18 AM
Why the lack of power? Meka Engine 3 02-23-2004 07:17 PM
Lack of power dion Engine 1 07-13-2003 03:31 PM


All times are GMT -6. The time now is 01:53 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.