Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 07-22-2001, 11:46 AM
jimm II's Avatar
jimm II jimm II is offline
Member
 
Join Date: Mar 2001
Location: Ontario,Canada
Age: 64
Posts: 399
Question ThermoQuad Question

Have friends out camping near us :They have a 1975 motor home 440 4bbl Thermoquad carb. They said that ,when they stick their foot in it . The engine stumbles and bletches out black smoke.When they ease into the pedal the speed picks up slowly.
I looked at the carb and it looks fairly new/rebuilt. I sugested that they check the filters on the carb and the two at the tanks.
I was also told that this was the first trip this year, and they did not flush or add stable to tanks over winter. Just wondering if I help them flush the fuel in tanks if it would get rid of any moister and /or rust. Any thoughts would be helpful ... Thanks everyone
Reply With Quote
  #2  
Old 07-22-2001, 11:50 AM
rumblefish360's Avatar
rumblefish360 rumblefish360 is offline
Moparchat Bronze member
 
Join Date: May 2000
Location: C
Age: 57
Posts: 11,120
Default

Black smoke? OIL, rings, rich, stumble, incorrect pump shot, secondarys opening to fast, wrong spring in it.
Reply With Quote
  #3  
Old 07-22-2001, 11:56 AM
jimm II's Avatar
jimm II jimm II is offline
Member
 
Join Date: Mar 2001
Location: Ontario,Canada
Age: 64
Posts: 399
Post

Thanks rumbblefish 360; The ideas will give me ideas where to start. My concern about the fuel being dead was ,because they told me that last year the moble home run like a top. When I seen it this morning the smoke loked dark grey. Thanks rumbblefish . When I felt spring tension on secondary plate it felt Very week. Maybe not adusted properly ? just a thought..
Reply With Quote
  #4  
Old 07-22-2001, 02:59 PM
Mean68Charger Mean68Charger is offline
Inactive User
 
Join Date: May 2001
Location: Glendale AZ
Age: 43
Posts: 20
Default

tighten up the air door a 1/4 turn at a time until the bog is gone
Reply With Quote
  #5  
Old 07-22-2001, 05:10 PM
jimm II's Avatar
jimm II jimm II is offline
Member
 
Join Date: Mar 2001
Location: Ontario,Canada
Age: 64
Posts: 399
Cool fun in the sun

Changed fuel filters, two on tanks and one in carb (that one I got from a carb in the garage). Found lots of rust and shit in lines,cleaned as best I could at park. Tighten air door ,just till closes plus two turns.
Friends said they would get it tuned up when they got home,later in week. Seems to run a little better,though didn't take for a road test.Sucking gas in this heat is not funn. Thanks for all the help guys, I hope this works out for them.
Reply With Quote
  #6  
Old 07-22-2001, 11:54 PM
Dr. Righteous Dr. Righteous is offline
Inactive User
 
Join Date: Dec 1999
Location: RURAL Tennesse
Age: 58
Posts: 1,839
Default I wouldn't coment but I have seen that before!

Stumbles and belches black smoke. A company I worked for had a '88 Ram Van w/318. After about 200K miles you could put your foot on the gas and fill the parking lot with BLACK smoke.
A fun thing to do was to line up the tail pipe with someone in a small car with the driver side window open. Pop the van into neutral and stomp the gas petal. The van would BLAST black smoke like a coal fired steam engine. It was a mean thing to do but it was so damn funny we couldn't resist. The 318 finally gave up and after it was yanked out and tore down it was discovered that one of the pushrods actually wore through a rocker on one cylinder. A exhaust valve was barely opening if at all. This caused a huge carbon build up in the exhaust system hense the black smoke.
Reply With Quote
  #7  
Old 07-24-2001, 01:26 AM
raymond raymond is offline
Inactive User
 
Join Date: Sep 2000
Location: Goolwa s. australia
Posts: 73
Default

Something else you might check is the slow opening diaphram. Its located on the back corner of the carb on the opposite side from the throttle lever. If this has failed the secondary air door will flop wide open on the opening of the secondaries and cause a stumble and also the over rich condition.
Reply With Quote
  #8  
Old 07-24-2001, 05:46 AM
jimm II's Avatar
jimm II jimm II is offline
Member
 
Join Date: Mar 2001
Location: Ontario,Canada
Age: 64
Posts: 399
Post

We're going out there for supper tonight, hope it cools down a bit. But I will check that diapham, They said they are heading home in a day or two ,Just want to help them make it home with lease amount of problems. My guess is the engine is just old and tired and needs to be overhauled.When our friends get home they said they would get it tuned up. Will check it out again tonight, to see if I've overlooked anything small . Thanks for the replies. This board and the people have been a great help.... Jimm II
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Thermoquad question Jim13 Restoring your MoPar (Tricks & techniques) 6 05-27-2007 02:30 AM
thermoquad question benwest Performance Talk 4 09-17-2004 10:41 PM
Thermoquad question HDDuece Performance Talk 10 09-02-2004 12:02 AM
Thermoquad Question Tarrbabe Performance Talk 21 04-28-2002 09:16 PM
thermoquad question amclipper Performance Talk 18 10-12-2001 03:02 PM




All times are GMT -4. The time now is 01:46 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .