dualjet 210. 260 and factory 5 speed
#1
dualjet 210. 260 and factory 5 speed
i have a 78 cutlass supreme with a 260 and factory five speed. the carburetor is a dual jet 210. the carb has been rebuilt twice by two different people and no luck it still is crap. if anyone has any info on this carb or has on they dont need anymore it would be much appreciated.
#2
http://www.ebay.com/itm/Acdelco-12-9...896818&vxp=mtr
Apparently a factory rebuild, and one heck of a good price!
Apparently a factory rebuild, and one heck of a good price!
#4
wmachine thanks for looking into it but my 78 260 will only take a dual jet 210. that dual jet is a little different then the one on mine. no one make a after market intake manifold or adapter plate so im stuck with the dual jet 210. other wise id do a holly or el.
#6
hey dmullin whats going on with it is hard to explain top end is gone. wont idle unless the butterfly is almost closed ( tried many things to fix that) when the rpms go down from a throttle it will die (some say back pressure some say timing some say just fuel problems.)
the car is my daily driver and it gets me from a to b. at one point i was getting 20 mpg now im geting 12. some people get there 260's up to 24 mpg. and gas mileage is the only reason i keep the 260 plus the rare/cool factor of the 260 and factory five speed combo.
the car is my daily driver and it gets me from a to b. at one point i was getting 20 mpg now im geting 12. some people get there 260's up to 24 mpg. and gas mileage is the only reason i keep the 260 plus the rare/cool factor of the 260 and factory five speed combo.
#7
hey drolds. i think the carb is just warped i can hear air leaking from it and as of recent fuel.the car wont stay running with the buttterfly wide open i have to keep it almost closed. its been rebuilt twice not by me. because i dont have the best understanding of how just yet. but im learning. ive owned this car since my twentieth birthday and im 21 now. this car has been a learning processes. who ever has owned the car in the last 35 year has taken good care of the body and the interior. but the motor was not.
#8
http://www.ebay.com/itm/Acdelco-12-9...896818&vxp=mtr
Apparently a factory rebuild, and one heck of a good price!
Apparently a factory rebuild, and one heck of a good price!
WTH would anyone modify a 7028251 into a Dualjet unless the carb had mangled secondaries or something
#9
#10
#11
the carb on ebay want the right one for my motor. but i do agree the one you speak of in much better and makes more sense but the issue is the 260 has an intake manifold that only fits a dualjet 210. and there are no after market intakes for this motor. i would much rather put a normal 4 barrel or 2 barrel on it.
#12
The discontinued Edelbrock SP2P intake will fit, small triangular ports. I sold mine to a member for his 260. Others have used the 85 and later A5 intake with some grinding to match the ports.
#13
#14
If he has the same dual jet as the 77 'f' 260 then that wont be it.
The type he has may look like a q jet with the secondaries blocked by casting. It is an oddball, they also set the float specs too low and made them more anemic than necessary. No idle and poor mileage could be a basic carb problem, like a missing casting plug or vacuum leak etc.
The type he has may look like a q jet with the secondaries blocked by casting. It is an oddball, they also set the float specs too low and made them more anemic than necessary. No idle and poor mileage could be a basic carb problem, like a missing casting plug or vacuum leak etc.
#15
If he has the same dual jet as the 77 'f' 260 then that wont be it.
The type he has may look like a q jet with the secondaries blocked by casting. It is an oddball, they also set the float specs too low and made them more anemic than necessary. No idle and poor mileage could be a basic carb problem, like a missing casting plug or vacuum leak etc.
The type he has may look like a q jet with the secondaries blocked by casting. It is an oddball, they also set the float specs too low and made them more anemic than necessary. No idle and poor mileage could be a basic carb problem, like a missing casting plug or vacuum leak etc.
Like this one?
#18
You say it wont run unless you close the butterfly almost completely? Do you mean the choke plate? If so it sounds like you have a huge vacuum leak somewhere. Check for that maybe a easy fix.
#19
After rereading the symptoms I would wonder about cat backpressure...carbs get blamed too often
Drill a small hole in front of cat, then read from a fuel pressure gauge.
Should be under 1.5 psi under throttle application.
Drill a small hole in front of cat, then read from a fuel pressure gauge.
Should be under 1.5 psi under throttle application.
#20
hey drolds. i think the carb is just warped i can hear air leaking from it and as of recent fuel.the car wont stay running with the buttterfly wide open i have to keep it almost closed. its been rebuilt twice not by me. because i dont have the best understanding of how just yet. but im learning. ive owned this car since my twentieth birthday and im 21 now. this car has been a learning processes. who ever has owned the car in the last 35 year has taken good care of the body and the interior. but the motor was not.
#22
reply to all with pics of carb.
PLEASE READ! hey guys thanks for all the reply's on the subject and all of the diagnosis's seem to fit what wrong with my cutlass. I attached a few pics of the motor and carb to this post so if anyone has any info from the pics about what is wrong (which i think is alot of thing.) that would be awesome.
so here is what i have gathered. the car is straight piped like the last owner just cut the pipe right where it reaches the end of the driver door. so no muffler or cats(dont know if it came with a cat converter.) which makes me believe that part of it is a BACK PRESSURE issue.
now if you look at the pictures there are barley any vacuum lines and alot of ports are caped off. the hot air choke is not connected, just bolted from the hose. all fuel emissions parts are missing. so now the question is how do i hook everything back up and what do i need? does anyone have a proper running 260 who can give me detailed pics and a description of how to run all the vacuum lines? possibly a video?
aiight guys now ill reply to each individual post thank you all and this is a kick *** community!
so here is what i have gathered. the car is straight piped like the last owner just cut the pipe right where it reaches the end of the driver door. so no muffler or cats(dont know if it came with a cat converter.) which makes me believe that part of it is a BACK PRESSURE issue.
now if you look at the pictures there are barley any vacuum lines and alot of ports are caped off. the hot air choke is not connected, just bolted from the hose. all fuel emissions parts are missing. so now the question is how do i hook everything back up and what do i need? does anyone have a proper running 260 who can give me detailed pics and a description of how to run all the vacuum lines? possibly a video?
aiight guys now ill reply to each individual post thank you all and this is a kick *** community!
Last edited by riggsmagoo; March 8th, 2014 at 02:51 PM. Reason: this post is important!
#23
intakes
interesting i have heard of people taking olds 350 intakes manifolds and welding and dremling them so the ports match up because they will bolt on just the ports dont match there too big for the bore. but i didnt know there were others that bolt on too!
#24
dualjets and quadrajets.
#26
vacuums
greg i think that is a BIG part of the problem! a few posts up from this i have pics of the carb on the block how it is and running take a look at the vacuum lines(there almost all gone) and i had to wire the flap on the top of the carb (what i call the butterfly) to a certain point so it will idle.
#27
dmullin backpressure
the exhaust looks like the stock one but what one of the last owners did was cut it right where it reaches the end of the driver door. so its just "straight piped" no muffler or cat.
#29
carb #
Yes thats typical of that dual jet turd. You can find them new nos. I may even have one. Whats the carb #. Does it have the heat plate gasket under it like the vari-jet turds? Your likely better off trying to find an alternative like a Ebrock. Ebrocks are very user friendly. Cool set up with the stick shift.
#31
Yes thats typical of that dual jet turd. You can find them new nos. I may even have one. Whats the carb #. Does it have the heat plate gasket under it like the vari-jet turds? Your likely better off trying to find an alternative like a Ebrock. Ebrocks are very user friendly. Cool set up with the stick shift.
#32
heat riser gasket
yes it used to have a heat riser gasket on it but i left it at orileys and they threw it away ha..... and im really not sure if the throttle body is damaged it seems fine. i just concluded that since its missing so much vacuum lines and alot of what they go to are caped off on the intake and the carb that is a big issue haha..... oh boy....
#38
![Exclamation](https://classicoldsmobile.com/forums/images/icons/icon4.gif)
Before you go to drastic measures like swaps etc, I think you should eliminate the simple stuff first.
If the egr valve (the mushroom looking thing on the intake) is stuck open internally, it can cause hard start, no idle and other driveability problems.
You would need to remove it to inspect it and make sure the valve is closing properly.
Even if the vacuum line to it is disconnected, it can still cause these symptoms.
Making a block off gasket out of steel can be done to eliminate that as a cause as this would stop the exhaust gas from dilluting the intake charge.
Now, it would help all the readers to know why the carb was rebuilt in the first place? Unless of course I missed that part..
If the egr valve (the mushroom looking thing on the intake) is stuck open internally, it can cause hard start, no idle and other driveability problems.
You would need to remove it to inspect it and make sure the valve is closing properly.
Even if the vacuum line to it is disconnected, it can still cause these symptoms.
Making a block off gasket out of steel can be done to eliminate that as a cause as this would stop the exhaust gas from dilluting the intake charge.
Now, it would help all the readers to know why the carb was rebuilt in the first place? Unless of course I missed that part..
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