Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > Vintage RV's
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-01-2013, 07:54 AM   #169
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by stink View Post
During your test drive, if you get stumbling when stepping on gas leaving a stop your rich, close idle screws 1/8 turn. If you get backfire or hesitation at accel from stoplight you are lean, open needles 1/4 turn and you should be drivable. Congrats on getting to run good!
I did a test drive around the block a few times and yes it backfired, gasped and hesitated from stop to go unless I very gingerly gave it some gas, guess it is lean, I will have to go thru all that to open the adjusters a 1/4 turn
__________________

__________________
Bilito is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-01-2013, 12:17 PM   #170
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
I did a test drive around the block a few times and yes it backfired, gasped and hesitated from stop to go unless I very gingerly gave it some gas, guess it is lean, I will have to go thru all that to open the adjusters a 1/4 turn
My neighbor and I managed to home make a tool from several tools and got it in the adjusters and we backed them both out 1/4 turn. Gonna get some lunch now and test drive it again
__________________

__________________
Bilito is offline   Reply With Quote
Old 07-01-2013, 01:45 PM   #171
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
LOL - Necessity is the mother of invention!
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 07-01-2013, 02:28 PM   #172
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
LOL - Necessity is the mother of invention!
Another 5 miles are on it, we got it good and warmed up, it still snorts and backfires if I push it a little hard from a stop, looks like another 1/4 turn out on those adjusters.
Hard to believe but it is actually running smoother and just a little faster (more rpm) then before the last 1/4 turn out
__________________
Bilito is offline   Reply With Quote
Old 07-01-2013, 05:45 PM   #173
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
Thats normal. You are adjusting the fuel air mixture used at idle.
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 07-01-2013, 09:08 PM   #174
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
Thats normal. You are adjusting the fuel air mixture used at idle.
Normal??
The engine speeding up or backing out another 1/4 turn
__________________
Bilito is offline   Reply With Quote
Old 07-02-2013, 07:46 AM   #175
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
In the old days, having to adjust the idle air mixture screws is normal after a rebuild or as part of a tune up. The OEM's covered up the screws so that the end user did not change the settings for emissions regulations. As you found, either someone had already messed with them or vibration caused them to change. The old day process was:

Start at 1 1/2 turns.
Slowly turn each needle outward until max RPM is achieved.
Adjust idle RPM back to spec
Verify no further change in needle setting increases the RPM

As you adjust them, changing the idle Air/Fuel mixture, the engine is responding to the change by speed change indicating you are approaching the sweet spot for lack of a better description. That point where the most energy is extracted from the air/fuel mixture.

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 07-02-2013, 11:18 AM   #176
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
In the old days, having to adjust the idle air mixture screws is normal after a rebuild or as part of a tune up. The OEM's covered up the screws so that the end user did not change the settings for emissions regulations. As you found, either someone had already messed with them or vibration caused them to change. The old day process was:

Start at 1 1/2 turns.
Slowly turn each needle outward until max RPM is achieved.
Adjust idle RPM back to spec
Verify no further change in needle setting increases the RPM

As you adjust them, changing the idle Air/Fuel mixture, the engine is responding to the change by speed change indicating you are approaching the sweet spot for lack of a better description. That point where the most energy is extracted from the air/fuel mixture.

Dave
Unfortunately for me and possibly for you, we both were there in the Old Days. Back in my teens I had an old style timing light, (only worked in the dark) and a vacuum gauge in my tool kit, I always carried that in the trunk and I used them a lot.

I do not understand why they designed this motor to be so incredibly hard to work on, unless as you say, it was all for emissions and to hell with us adjusting for better performance or fuel economy.

I have a Jeep Grand Cherokee and I can not even adjust the idle speed, it is all done with sensors and computers, mine kept stalling at lights when it was a hot day, and I wanted to increase the idle by about 100 rpm, there is no idle speed adjusting screw. Got a small drill, made a hole in a stop, screwed in a self tapping screw and made an adjustment to boost the rpm about 100 rpm and it has never been an issue again.

A year ago we drove over to the BIG RV SHOW in Tampa and on the way back suddenly the car would not go any faster then 50 mph, any attempt to do so and the motor quit, we had to drive across Alligator Alley at night in a light drizzle below 50 mph and caused a backup behind us that was a half mile long, everyone was going at 70 MPH or more and trying to pass us. Turns out a sensor called the throttle position indicator (TPI) suddenly failed, the part was around 10 bucks or so and it sure did cause a lot of, horn honking, middle finger extended, fist waving etc, as they finally passed us, so much it became funny after a while, and we waved back. These modern engines give no warning, they just suddenly have issues and always at the worst possible time and place and are impossible to just fix.

Right now it is pouring rain, the RV is sitting surrounded by a small puddle, so adjusting those screws out another 1/4 turn will have to wait, think I will check the Vacuum before and after I make the adjustment, hopefully it will show a small increase.
__________________
Bilito is offline   Reply With Quote
Old 07-02-2013, 09:27 PM   #177
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
I feel your pain. I have a 92 Chevy Lumina APV (mini-van) with a 3800 FI V6 that uses OBD1 brains. OBD1 does not give you any where near the fault codes a OBD2 (96 & later) system does. Lots of hair pulling with OBD1.

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 07-03-2013, 09:05 AM   #178
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
I feel your pain. I have a 92 Chevy Lumina APV (mini-van) with a 3800 FI V6 that uses OBD1 brains. OBD1 does not give you any where near the fault codes a OBD2 (96 & later) system does. Lots of hair pulling with OBD1.

Dave
Curious Thing I just noticed
Just inside the throat of the carburetor below the choke plate is the squirters. One of them is giving a steady stream of fuel, the other is spraying out fuel. Could this in itself be an issue possibly causing some hesitation and backfiring thru the carb.?????
__________________
Bilito is offline   Reply With Quote
Old 07-03-2013, 09:23 AM   #179
Senior Member
 
Join Date: Sep 2007
Location: texas
Posts: 2,268
They both should give you a squirt( stream) if I remember it is held in with a Phillips screw
__________________
whem2fish is offline   Reply With Quote
Old 07-03-2013, 01:12 PM   #180
Senior Member
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 1,513
Please refer to pdf page 4 of http://www.holley.com/data/TechServi...ech%20Info.pdf for an explanation of the Accelerator Pump system. Fuel should only be squirted out when you depress the accelerator. No fuel should should be squirted when the accelerator is held steady. It should be a stream not mist. Sounds like there may be dirt in one of the nipples.

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 07-03-2013, 06:22 PM   #181
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Dave78Chief View Post
Please refer to pdf page 4 of http://www.holley.com/data/TechServi...ech%20Info.pdf for an explanation of the Accelerator Pump system. Fuel should only be squirted out when you depress the accelerator. No fuel should should be squirted when the accelerator is held steady. It should be a stream not mist. Sounds like there may be dirt in one of the nipples.

Dave
Yea I know, I have to plug the air intakes with rags to get that squirter out, the screw is not quite out in the open and there is a gasket above and below the squirter, I had it out, blew air thru it while on the bench, amazing how quickly something can mess up the works. If I drop anything, down into the intake it goes.
Do you think that mist on one side and a stream on the other could cause it to backfire and stubble on acceleration from a stop?????
__________________
Bilito is offline   Reply With Quote
Old 07-03-2013, 06:46 PM   #182
Senior Member
 
Join Date: Jan 2012
Posts: 683
Quote:
Originally Posted by Bilito View Post
Yea I know, I have to plug the air intakes with rags to get that squirter out, the screw is not quite out in the open and there is a gasket above and below the squirter, I had it out, blew air thru it while on the bench, amazing how quickly something can mess up the works. If I drop anything, down into the intake it goes.
Do you think that mist on one side and a stream on the other could cause it to backfire and stubble on acceleration from a stop?????
Right from the manual you sent, answered my own question, gotta clean that nozzle (squirter) out.

[During acceleration tests, if you notice that the car first hesitates and then picks up, itís a sure bet that the pump nozzle size should be increased. A backfire (lean condition) on acceleration also calls for a step up in pump nozzle size]
__________________

__________________
Bilito is offline   Reply With Quote
Reply

Tags
ford



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

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:09 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.