total timing is measured at full advance and inital timing is what its set to start the motor (no advance)
CK5
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motor problems still...UPDATED...HORRIBLE MPG
- Thread starter 01maroonz71
- Start date
MuddinManny
Banned
onetonbb74 said:
Ahhhhhhhh! Thank you!
onetonbb74 said:
01maroonz71
1/2 ton status
well...here's an update ya'll....i swapped the fuel filter today(nasty as fug....won't flow worth a damn) and got a K&N 4 1/2in filter today, see what that does...i also filled up with premium and backed the BTDC timing down to 8degrees....and left idle where it was....
heres a pic of hte filter(sorry about picture quality, camera phone blows) but you can see all the brown crap caked on it...what could that be...i also tested the "flow" in the kitchen sink compared to a new one, and it didn't flow worth a damn....
what could that have caused this????? anybody got any clues???
another thing the truck is doing is...it's like the idle changes, sometimes it idles down to about 800RPM in gear after i stop at a light, then if i throw it in N or Park and tap the pedal once or twice it will idle down to about 500RPM(what i have it set at) any ideas about this!!!!
thanks again ya'll.
heres a pic of hte filter(sorry about picture quality, camera phone blows) but you can see all the brown crap caked on it...what could that be...i also tested the "flow" in the kitchen sink compared to a new one, and it didn't flow worth a damn....
what could that have caused this????? anybody got any clues???
another thing the truck is doing is...it's like the idle changes, sometimes it idles down to about 800RPM in gear after i stop at a light, then if i throw it in N or Park and tap the pedal once or twice it will idle down to about 500RPM(what i have it set at) any ideas about this!!!!
thanks again ya'll.
SUBFAN
1/2 ton status
38377k5 said:
Not true....Internally balanced cranks can be purchased to make a 383, thereby rendering this statement false....
01maroonz71 said:well...here's an update ya'll....i swapped the fuel filter today(nasty as fug....won't flow worth a damn) and got a K&N 4 1/2in filter today, see what that does...i also filled up with premium and backed the BTDC timing down to 8degrees....and left idle where it was....
heres a pic of hte filter(sorry about picture quality, camera phone blows) but you can see all the brown crap caked on it...what could that be...i also tested the "flow" in the kitchen sink compared to a new one, and it didn't flow worth a damn....
what could that have caused this????? anybody got any clues???
another thing the truck is doing is...it's like the idle changes, sometimes it idles down to about 800RPM in gear after i stop at a light, then if i throw it in N or Park and tap the pedal once or twice it will idle down to about 500RPM(what i have it set at) any ideas about this!!!!
thanks again ya'll.
Well most likely your high idle is sticking slightly, or your throttle linkage is binding. Check the opperation of the linkage and the fast idle cam, also make sure your throttle cable is lubed (same as other parts as far as lubing them).
01maroonz71
1/2 ton status
awesome...ill check it all out today for sure...thanks man!
I'd get rid of the Holley and put a Quadra-Jet back on. Edelbrock makes good replacement QJ's.
I will let the others chime in on their opinions about the QJ's.
I will let the others chime in on their opinions about the QJ's.
camarossguy2
1/2 ton status
38377k5 said:
Thats not true. You can buy both internal or external balancing cranks for 3.78, 3.75, 4.00'' stokes.
kwissman
1/2 ton status
Your idle problem may be caused by not having the vacuum advance hooked up. If the vac advance is not being used it needs to be locked out in the distributor. If you have a MSD they make a kit to do it. Otherwise hook it up. The vac advance will help with a better idle and gas mileage. It has no effect on WOT operation.
Also, you stated that the timing was advancing right off idle. Your timing curve should not come into play until around 1200 rpm. Otherwise, you will sometimes be advanced at idle and othertimes at the base. You need to map your timing curve and see when it starts to advance and at what rpm you get total advance. You should get total advance by 3000 rpm for a performance motor and have about 36-38 total. The timing curve is adjusted by changing springs to make it advance faster. My MSD has stops of different sizes to limit the total advance.
When determining the advance curve, you need to disconnect the vac advance and cap off the port. You can hook the vac advance to ported or full manifold vac. I have mine hooked to full manifold vac to get better idle and more advance. Ported will only provide vac advance at off idle and part throttle situations.
Kent
Also, you stated that the timing was advancing right off idle. Your timing curve should not come into play until around 1200 rpm. Otherwise, you will sometimes be advanced at idle and othertimes at the base. You need to map your timing curve and see when it starts to advance and at what rpm you get total advance. You should get total advance by 3000 rpm for a performance motor and have about 36-38 total. The timing curve is adjusted by changing springs to make it advance faster. My MSD has stops of different sizes to limit the total advance.
When determining the advance curve, you need to disconnect the vac advance and cap off the port. You can hook the vac advance to ported or full manifold vac. I have mine hooked to full manifold vac to get better idle and more advance. Ported will only provide vac advance at off idle and part throttle situations.
Kent
01maroonz71
1/2 ton status
awesome kent, thank you so much for your help.h...i will try to hook up to full manifold vac and see if that helps at all. i geuss i need to get a new timing light so i can check how much advance im getting. since the motor is advancing right off idle, how i change that???? i know that i can change the stops in the dizzy to limit the total advance and i can make it advance faster with diff. sprigs. thanks alot guys!!!!
edit****
also..would going back to a Q-Jet help my mileage and so on?? that may be my best bet. i have had about 5 people aroudn town tellin me to get rid of my holley w/ dual feed fuel lines. they say that's whats giving me 5MPG.
im going to try backing the timing down a bit more today and fill up with premium also...im going to try about 4 or 6degrees BTDC and see if it still pings under throttle(like it is now)
edit****
also..would going back to a Q-Jet help my mileage and so on?? that may be my best bet. i have had about 5 people aroudn town tellin me to get rid of my holley w/ dual feed fuel lines. they say that's whats giving me 5MPG.
im going to try backing the timing down a bit more today and fill up with premium also...im going to try about 4 or 6degrees BTDC and see if it still pings under throttle(like it is now)
01maroonz71 said:
Yes, yes and yes...
01maroonz71 said:
Well, ya your mileage might pickup if you go to a q-jet, but it will definately hurt performance. You can't beat a Holley for performance. I know alot of people here praise the q-jet for its simplicity and ability to run at crazy angles. But I vote Holley all the way!
It is possible that your horrible mileage is contributed to the fact that I seriously doubt that your carb is properly tuned for your application. There is no universal tune for a carb, there are so many variables that it will boggle your mind.
Also are you sure that you don't have a mechanical secondary carb? A lot of Holley double pumpers are mechanical.
Also do you have a manual choke or electric? What cfm is it? Do you know what series it is? Maybe post a pic and we could tell you.
look here: http://www.holley.com/data/Products/Technical/199R7923-2.pdf
Are you sure this is a double pumper carb? A true double pumper will have an accelerator pump on the bottom of each float bowl. the vac secondary will have a metal can on the pass side of the carb with a diaphram in it that opens by vaccum. The timing issue may be computer related also, Does it have Electronic Spark Control?
01maroonz71
1/2 ton status
well...i just went and snapped some shot of her...i assumed it was a double pumper since my buddy with a double pumper said it was one the other day...but you know what happens when you ASS-YOU-ME things.
i couldn't find any part numbers or anything, but im going to use these pics as a reference right now
also, if i needed to have it tuned, should any local shop be able to do that, i would like to do it myself, but don't know squat about carbs...but am definately willing to learn if anybody knows any good articles,or books that would help.
well, here are some pics:
i couldn't find any part numbers or anything, but im going to use these pics as a reference right now
also, if i needed to have it tuned, should any local shop be able to do that, i would like to do it myself, but don't know squat about carbs...but am definately willing to learn if anybody knows any good articles,or books that would help.
well, here are some pics:
01maroonz71
1/2 ton status
Ok, looks like it's a 4150 carb.....but see the flap on the top that's wide open??? on my 87's brand new edelbrock 1406...those stay shut when the trucks not running...I believe that's the choke and it's wide open right??? well, why would it be stuck open like that if i shut the truck off after it warmed up last time...could that be screwin with my mileage???? and possibly cause my other probs..pinging, etc.????
thanks for the help ya'll....im off to tractor supply to check out their tow straps.
thanks for the help ya'll....im off to tractor supply to check out their tow straps.
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http://www.holley.com/data/Products/Technical/199R9934-3.pdf
http://www.holley.com/0-80508S.asp
Sorry I gave you the wrong link before. But it seems to me like you got a 4160 actually.
01maroonz71 said:
That "flap" you are refering to is the choke. The choke only effects the primaries and should be fully open, yours looks like its closed slightly. That could be the cause of the engine not idling down. So you need to adjust that, refer to the one of the links I gave you to learn how to adjust it.
The secondaries are a separate circuit that only opens under load, when the engine is in need of the extra air. If they open to soon the engine will bog or if they open too late then your engine will hit a flat spot then really take off.
Read through Holley's instructions on tuning the carb, if you still have any questions, I'll be happy to do my best to answer them.
Thats a 4160 vacuum secondary carb, should be ok. This is not a double pumper as there is only one accelator pump on that carb. The Choke flap should be closed when its cold/ first start up of the day. Otherwise, the flap should remain open all the time. To start tuning this carb, Id first check the needle and seat which is located where the flat head skrew(big) on the top of the bowls. Then id adjust the float level by unskrewing the sight plugs, the level of the gas as it should be level with the sight plug bottom threads while the engine is running (be careful, gas will go everywhere so bring some rags for this). to adjust the bowl up and down, turn the needle and seat hex head left and right after loosing up the set skrew on top (flat head). Id then do the air/fuel mixture skrews while hooking up a vacuum guage to the intake manifold. I like to start with 2 full 360 degree turns out then go from there. If it has no power, or is still wasting gas, Check the vaccum at idle in gear (auto) or neutral (stick) then get the appropiate power valve. (lets say you have 16lbs of vaccum at idle in gear, then you would need a 8.5 power valve. General rule of thumb, is divide vacumm by 2 then add .5.
01maroonz71
1/2 ton status
Thanks alot ya'll...im going to clean the **** out of it too...will too much carb cleaner sprayed in there hurt anything????
and, if that's the case...it's a 750 CFM because this one.....
http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D0%2D3310C&N=700+4294919007+300737+1051506943+115&autoview=sku
and i can't find a 600 dual feed with electric choke/vacc. secondaries, only a 750CFM
...wouldn't that be way to much for a 350????? don't i need a 600 or 650???could that kill my mileage????
and, if that's the case...it's a 750 CFM because this one.....
http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D0%2D3310C&N=700+4294919007+300737+1051506943+115&autoview=sku
and i can't find a 600 dual feed with electric choke/vacc. secondaries, only a 750CFM
...wouldn't that be way to much for a 350????? don't i need a 600 or 650???could that kill my mileage????
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