Losing my Mind, 340 Six pack wont pull
#2324966
06/21/17 11:01 PM
06/21/17 11:01 PM
|
Joined: Apr 2015
Posts: 58 Wi
Scat
OP
member
|
OP
member
Joined: Apr 2015
Posts: 58
Wi
|
Been Fighting it since i got the car running. Every time i go to get on it the car will simply cut out and wont pull anything past 3100rpm. Pulls fine till then but after that it hits a wall. I want to make it work and not just toss a 4 barrel on it. Heres what i have done already, New ECU New Dist pick up New Ballast resistor Timing at 10 Deg and no vacuum advance total timing at 36 All carbs have been gone through fully Changed out secondary springs to differnt colors light to heavy springs and still the same Car Has new valve springs, cam and lifter 14-15 vacuum at idle 63 main jets and stock secondarys. Idles and free revs great. no hesitiation. new fuel filter. Plugs are RN9YC @ .040 gap
Insight would be apprecated to who ever has owned one of these animals.
73 Duster 340 a518 6pack
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2324982
06/21/17 11:24 PM
06/21/17 11:24 PM
|
Joined: May 2003
Posts: 96,649 On The Boat, On The Lake, Wa. ...
amxautox
Still Retired. Still Posting on Moparts. A Lot.
|
Still Retired. Still Posting on Moparts. A Lot.
Joined: May 2003
Posts: 96,649
On The Boat, On The Lake, Wa. ...
|
What is the psi of the fuel pump? Are you positive the secondaries are opening?
Tom
"Everyone should believe in something; I believe I'll go fishing."
-Henry David Thoreau
Men and fish are alike. They both get into trouble when they open their mouths
author unknown
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2324993
06/21/17 11:33 PM
06/21/17 11:33 PM
|
Joined: Jan 2003
Posts: 14,491 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
|
The one aspect of trying it with a 4bbl is.......it will help point you where to look for the problem.
If the 4bbl fixes it, it's a carb problem.......and visa-versa.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: amxautox]
#2325005
06/21/17 11:51 PM
06/21/17 11:51 PM
|
Joined: Apr 2015
Posts: 58 Wi
Scat
OP
member
|
OP
member
Joined: Apr 2015
Posts: 58
Wi
|
6psi and yes they are opening. Set a gopro under the hood to verify.
73 Duster 340 a518 6pack
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325035
06/22/17 12:58 AM
06/22/17 12:58 AM
|
Joined: Jan 2003
Posts: 14,491 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
|
Wire the secondaries closed and see what happens.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: fast68plymouth]
#2325081
06/22/17 03:39 AM
06/22/17 03:39 AM
|
Joined: Dec 2003
Posts: 4,951 northwest USA
NANKET
master
|
master
Joined: Dec 2003
Posts: 4,951
northwest USA
|
Wire the secondaries closed and see what happens. That will not work out very well. If you want no secondary opening then disconnect the vacuum lines to the outboards.
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325088
06/22/17 04:42 AM
06/22/17 04:42 AM
|
Joined: Oct 2006
Posts: 427 Sweden
Mopar Guy
mopar
|
mopar
Joined: Oct 2006
Posts: 427
Sweden
|
1.Have you set the fuel level corekt in the carbs ? 2. I would try to open the outer carbs whit engine on idel on the center carb and see if the engine responce like it should on those carbs to verify that they give the engine fuel.
I have not done any work on the sb 6-pack but on the bb they like larger main jets for preformance like 66-68.
It shore sounds like the outer carbs dont deliver fuel to the engine so are they assembeld corekt whit the corekt gaskets for the jet plates so the fuel holes aint plugd !?
Jerry Binder wrote a realy good articel that explain alot on the 6-pack carbs that i can email you if you like !?
Last edited by Mopar Guy; 06/22/17 05:09 AM.
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325096
06/22/17 05:01 AM
06/22/17 05:01 AM
|
Joined: Aug 2005
Posts: 5,998 Salem
Grizzly
Moparts Proctologist
|
Moparts Proctologist
Joined: Aug 2005
Posts: 5,998
Salem
|
I don't see new fuel pump on your list. You could be plugged off at the tank too with this crap they call "fuel" these days. Could be load of poo in there blocking your fuel lines.
Mo' Farts
Moderated by "tbagger".
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Grizzly]
#2325133
06/22/17 10:34 AM
06/22/17 10:34 AM
|
Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
(1) I'd T into the fuel line & see what psi you have "at speed" when it acts up. (2) Will it rev up normal like you want it to in your driveway? on the second suggestion, the fuel requirement wouldn't be the same cuz of the minimal load but you should be able to load it ign wise pretty good by gunning it to pin it to ign or fuel. keep us posted. & when it acts up does it spit & sputter or wont go any higher but is smooth or something else?
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325181
06/22/17 12:46 PM
06/22/17 12:46 PM
|
Joined: Apr 2015
Posts: 58 Wi
Scat
OP
member
|
OP
member
Joined: Apr 2015
Posts: 58
Wi
|
See if i can reply to everything asked.
All new fuel lines, tank and sending unit.
we put the secondarys to direct vacuum and reved it, the secondarys are working and dumping fuel.
The carb rebuild kits came from quick fuel.
going 75 in 4th is got nothing left in it. it just falls on ots face.
Ill see about fuel psi under load and see what happens.
73 Duster 340 a518 6pack
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325307
06/22/17 04:27 PM
06/22/17 04:27 PM
|
Joined: Jan 2003
Posts: 14,491 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
|
When I've needed to check fuel pressure at wot on the road, I just tape a small mechanical gauge to the windshield right where I can easily see it.
Although there was talk of a go-pro....... So I guess the gauge could be anywhere the camera could get a good look at it.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Scat]
#2325315
06/22/17 04:39 PM
06/22/17 04:39 PM
|
Joined: Oct 2004
Posts: 2,807 Connecticut
FurryStump
master
|
master
Joined: Oct 2004
Posts: 2,807
Connecticut
|
Sounds like fuel, it comes right back after the rpm decreases below the problem rpm? Have you check rotor phasing? Msd has a good video on it. Mine was just like the before video! DOH! Also check the burn pattern on the distributor terminals. Is it in the right spot? I chased this for a good bit of time!
Last edited by FurryStump; 06/22/17 04:40 PM.
|
|
|
Re: Losing my Mind, 340 Six pack wont pull
[Re: Moparteacher]
#2325435
06/22/17 09:53 PM
06/22/17 09:53 PM
|
Joined: Apr 2015
Posts: 58 Wi
Scat
OP
member
|
OP
member
Joined: Apr 2015
Posts: 58
Wi
|
If it's not fuel then it's a volumetric efficiency issue. Try this: Bring engine to operating temp. Place vacuum gauge to read manifold vacuum. Record vacuum reading at idle in park or neutral. Bring engine rpm up to 2500, hold, read vacuum gauge. Is the vacuum reading at 2500rpm the same or higher than the reading at idle? It should be same or higher.
If it's lower at 2500 rpm then it's a breathing problem. #1 Cam timing is incorrect. Remove valve cover, bring engine to TDC on exhaust stroke (360* from TDC compression stroke) using piston stop. Don't rely on dampner markings or timing chain markings. Inspect intake and exhaust rocker action as you rotate engine back and forth no more than 10*. Are both valves being activated? Exhaust closing and intake opening? Just did the vacuum test and in fact it is losing its vacuum as it revs. Did a quick comp test and 80psi all around. Gonna let it cool off then pull the cover yet tonight
73 Duster 340 a518 6pack
|
|
|
|
|