Q-jet throttle stuck open, backfired, and now won't idle - Page 2 - 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
  #16 (permalink)  
Old 09-08-2008, 09:04 AM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 64
Posts: 1,059
Wiki Edits: 0

Thanks: 1
Thanked 21 Times in 18 Posts
Cousin Joe, Must likely you may have one or two bent valves

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 09-08-2008, 07:36 PM
Registered User
 
Join Date: Sep 2007
Location: Grand Rapids, MI
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Compression Test Results

So I got the loaner compression tester from Autozone on the way home from work, and did the test tonight. Everything came out 150 +/- 5psi. I figured that was probably good news.

I spoke with Sean Murphy today since I got the carb from SMI, and I'm not real knowledgable about Q-jets. He said to try misting some carb cleaner over the carb while running. It slowed down the motor so I think I am running rich. That and the plugs looked 'fuel' wet when I pulled them for the compression test.
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 09-08-2008, 07:53 PM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,995
Wiki Edits: 0

Thanks: 2
Thanked 91 Times in 74 Posts
Pull the hat off the carb and check the secondary needles as posted before.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 09-08-2008, 07:54 PM
carsavvycook's Avatar
My 2 cents worth
 
Last photo:
Join Date: Sep 2007
Location: Lakeside, CA
Age: 57
Posts: 2,855
Wiki Edits: 3

Thanks: 2
Thanked 2 Times in 2 Posts
My thought now is debree in the needle and seat.

Did you use Tephlon Tape anywhere in the fuel supply system?

If so, it partialy disolves, and will keep the needle and seat open.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 09-09-2008, 06:49 AM
Registered User
 
Join Date: Sep 2007
Location: Grand Rapids, MI
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I haven't taken a Q-jet apart before, so I was a little hesitant to start there, but it does look like thats where I'm going.

I did use a small amount of teflon on fuel line inlet. I was very careful (or at least I was intending to be) to not put any on the first few threads. That was a last resort, I tried a few different times, but the fuel inlet just kept weeping fuel w/o anything on it.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 09-09-2008, 08:16 AM
Jmark's Avatar
Registered User
 
Last photo:
Join Date: Sep 2003
Location: phoenix
Age: 61
Posts: 4,844
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by Cousin_Joe
but the fuel inlet just kept weeping fuel w/o anything on it.
There is supposed to be a thin plastic washer that seals the inlet to the carb body. Maybe you missed it? On the later qjets, it's at the very end of the threads and is easy to overlook.

Mark
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 09-09-2008, 08:42 PM
Rustydawg's Avatar
Cruzin w/Elvis in Bigfoots UFO
 
Last photo:
Join Date: Nov 2004
Location: Edmonton AB, Great White North
Age: 49
Posts: 248
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
Power piston?

Is it possible that the brass power piston was driven to the end of it's bore from the backfire and now it's stuck there? That would make it run rich if it hasn't pulled back into the 'high vacuum' position.

I don't have that much Q-Jet time behind me, any of you Q-Jet gurus seen something like this? If a backfire can knock the secondary rods off the hangers...
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 09-12-2008, 05:50 AM
Registered User
 
Join Date: Sep 2007
Location: Grand Rapids, MI
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I pulled the top plate off yesterday and everything looked fine, piston, float, needles etc... so I fired it up and it seemed to run fine, took it around the block a few times with no adverse things noticed. It idled, and it would start w/o any problem.

Got in this morning to drive to work, and it flooded out and wouldn't start. Best bet looks like taking the whole thing apart cleaning/blowing and putting back together. Is an internal leak a possibility? I've got to be putting extra fuel in somewhere. Just trying not to go mental while I figure it out.

Last edited by Cousin_Joe; 09-12-2008 at 06:41 AM.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 09-13-2008, 07:46 PM
RODDER18's Avatar
Registered User
 
Last photo:
Join Date: Oct 2006
Location: Fargo
Posts: 381
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
When it flooded out did the carb over flow with fuel? If so you may have a piece of crap in the needle and seat...
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 09-15-2008, 05:34 AM
Registered User
 
Join Date: Sep 2007
Location: Grand Rapids, MI
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Got a kit for some new gaskets and went through the carb yesterday. I didn't find anything in the way of dirt/gunk, but what I did find was the clip/needle that attaches to the back of the float was stuck almost out of the seat. I think this could have had something to do with things, as it started up after I had things back on without any major problems. Exhaust smells a little rich, but I'm not fouling plugs, and I was able to drive to work today! Thanks for everyone's help with this, and now I'm a slightly more inclined with Q-jets that I was before this whole thing happened.
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:
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



All times are GMT -6. The time now is 04:04 AM.


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.