carb help need some new ideas - Great Lakes 4x4. The largest offroad forum in the Midwest

Go Back   Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > General Tech
GL4x4 Live! GL4x4 Casino

greatlakes4x4.com is the premier Great Lakes 4x4 Forum on the internet. Registered Users do not see the above ads.
Search
Reply
 
Thread Tools Search this Thread
Old July 31st, 2011, 05:17 PM   #1
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default carb help need some new ideas

i have a holley 670 truck avenger carb on a 318 with a mild cam. i have set the air screws in the front of carb to the higest vacuum point i can get. also check the pump shot lever for .15 gap. motor has new plugs,wires,cap,rotor and a non vacuum advance distributer. i have turned choke one click clockwise to make it stay on a little longer. that is about as i know about carb stuff now here is the prob.

when i first fire it up i can rev it and no prob. but under a load when im leaving a light u can hear a small pop from carb and it stumbles so i have to let off and easy back into it. it does it less often when it warms up but u can still feel the hesation when leaving a dead stop. once it gets rolling i can hammer it down and it runs great. any ideas on what i should try next.
im thinking turn choke on longer still
inceasing the squrtersize from stock 28 to a 30 or 32
also change cam for diff pump shot
i am at a loss with this thing so if anyone can point me into a better dirrection or has some idea on what i can try im all ears and thank you very much.
CHEROKEEMUDMAN01 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old July 31st, 2011, 06:10 PM   #2
don4life
Senior Member
 
don4life's Avatar
 
Join Date: 12-14-09
Location: Holland, MI
Posts: 778
iTrader: (6)
Mentioned: 0 Post(s)
Default

have you tried backing off the adj. for the accelerator pump/squirter sounds like your getting to much fuel from a dead stop
don4life is offline   Reply With Quote
Old July 31st, 2011, 06:27 PM   #3
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default

no i kept thinking it wasnt enough fuel but i will its worth a shot.
CHEROKEEMUDMAN01 is offline   Reply With Quote
Old July 31st, 2011, 07:57 PM   #4
frdboy
Wishin' I waz fishin'
 
frdboy's Avatar
 
Join Date: 03-29-06
Location: Grand Haven, MI
Posts: 10,801
iTrader: (25)
Mentioned: 6 Post(s)
Default

Normally when it pops thru the carb it's lean. Float levels right? Lose some of that gap in the pump lever. Increasing the squirter size may help as well.
__________________
Cheap Thrills Off Road

2003 F-250 4X4 7.3 PSD Crew Cab

1971 Bronco
frdboy is offline   Reply With Quote
Old July 31st, 2011, 08:20 PM   #5
itselliott
Senior Member
 
itselliott's Avatar
 
Join Date: 03-20-06
Location: Walhalla
Posts: 1,816
iTrader: (80)
Mentioned: 0 Post(s)
Default

Was thinking too little fuel also.....

just did an increase in fuel reaction on my boats 307 with quarajet by moving the acc/pump lever to a quicker reaction hole in the linkage to the pump.

solved the problem for me.
itselliott is offline   Reply With Quote
Old July 31st, 2011, 10:27 PM   #6
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default

forgot to add that but float levels are correct. it dosnt sound like a backfire but a light pop sound. i am going to order a holley cam kit and play with that also any reconadations on about what size squrter to run?
CHEROKEEMUDMAN01 is offline   Reply With Quote
Old August 4th, 2011, 07:29 PM   #7
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default

well i have increasing the squirter size to 31 and to 35 and that didnt help also tried white,green,red and blue cams with each squirter and that didnt help. i just cant win with this carb anyone know of any known issues with the truck avenger that ends in a -3. i havent seen anything on the dash 3 yet. holley hasnt been any help at all and im about ready to box it up and tell them to stick it up the ass. prob is its worse when its cold and after truck gets to operating temp it gets better but still not great by anymeans so i can only test and tune twice a night and been doing this for a week and a half and no foward progress. anyone got any other ideas i can try.
CHEROKEEMUDMAN01 is offline   Reply With Quote
Old August 5th, 2011, 07:06 AM   #8
GMKLR50
Broke wheeler
 
GMKLR50's Avatar
 
Join Date: 10-13-10
Location: White Lake, MI ( Detroit side of state)
Posts: 1,124
iTrader: (5)
Mentioned: 0 Post(s)
Default

i had the same problem with my truck avenger on a 318 in a ramcharger I sold a while back.....i could never get it running right... I tried a smaller carb and it solved the problem.... I think that your carb is to big...most 318's came with a 2 barrel and ran great...try taking fuel out of it...I think that you may be flooding it when you first take off.


by any chance is this set up in a 83 ramcharger two tone blue?
GMKLR50 is offline   Reply With Quote
Old August 5th, 2011, 07:45 AM   #9
frdboy
Wishin' I waz fishin'
 
frdboy's Avatar
 
Join Date: 03-29-06
Location: Grand Haven, MI
Posts: 10,801
iTrader: (25)
Mentioned: 6 Post(s)
Default

Did you buy this carb new?

Try opening the screws on the side of the front metering block 1/2 turn each.

I would also raise the float level on the front 3-5 flats just for testing to see if it helps or hinders.

Make sure you make only one change at at time so we know what direction to go.

What do you have timing at?
__________________
Cheap Thrills Off Road

2003 F-250 4X4 7.3 PSD Crew Cab

1971 Bronco
frdboy is offline   Reply With Quote
Old August 5th, 2011, 02:37 PM   #10
Elvis13
Senior Member
 
Join Date: 05-15-11
Location: Addison Township, MI
Posts: 1,180
iTrader: (7)
Mentioned: 0 Post(s)
Default

I'm having the exact same issue with my 390. It runs real cold blooded for about 2 minutes but i still have the initial stumble.

I would adjust the timing, fuel ratio screws and recheck the acc. pump.

What kind of fuel delivery system do you have? Does it sound like it is backfiring out the exhaust?
Elvis13 is offline   Reply With Quote
Old August 6th, 2011, 11:33 AM   #11
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default

this carb is on a 318 from a 85 b350 1 ton van and is in my 89 xj cherokee.

i have using the 28 squirter with the white cam (which i was told is least amout of fuel) and even loosened the screw on accel pump a few turns and it got worse. so i am leaning towards it needs more fuel. i then put in the 35 squirter and put accel pump spring back to norm and put in the blue cam ( middle size im told) and it got better but still has small backfire from carb on takeoff from dead stop.

i have been test driving after everychange to see what helps. i cant set the timing with gun because the dampner i ordered for it from summit has the timing marks way off (what a surprise lol). so i am setting it with the truck at 2000 rpms and listiningto it for the sweet spot. it has to be close no spark knock and when its hot it fires right up no slow crank or any sigh of timing being off.

air idle screws i have set to 11/2 turns out which is were it made its most vacuum and only puffs a light smoke on a hard rev up otherwise it exhaust is clear.

i have done everything but mess with power valve which i guess could be bad since it really is last thing. anyone know how to change one on this carb or a sight with some instructions to walk me through it. also how to i check it once i have it out.

thanks for all help guys i really do appricate it.
CHEROKEEMUDMAN01 is offline   Reply With Quote
Old August 6th, 2011, 11:36 AM   #12
CHEROKEEMUDMAN01
Senior Member
 
CHEROKEEMUDMAN01's Avatar
 
Join Date: 10-03-09
Location: warren mi
Posts: 732
iTrader: (13)
Mentioned: 0 Post(s)
Default

sounds like backfire through a carb. i am using a mech fuel pump rated for 80 gph and ran 6an line from cell to pump and a 5/16 steel line from pump to carb. the 318 is stock except i have a comp cam 448 lift truck cam in it so its still mild.
CHEROKEEMUDMAN01 is offline   Reply With Quote
Reply
Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > General Tech

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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


All times are GMT -5. The time now is 09:26 PM.


Powered by: vBulletin, Copyright 2000 - 2012, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
Page generated in 0.20449 seconds with 57 queries