Dodge RamCharger Central banner
1 - 20 of 29 Posts

·
Registered
Joined
·
240 Posts
Discussion Starter · #1 ·
Just picked up an 85 RC and noticed that after sitting overnight and starting up the next day the idle is really high in park, if I take it into reverse or drive it bangs into gear. When in park and I throttle the engine, the idle drops down. This is my first experience with a carb and was wondering some first steps to adjusting the idle speed. Thanks!
 

·
Registered
Joined
·
2,368 Posts
That is normal- a cold engine will be on fast idle.  May need some adjustment though.  need to know which carb (holley 2280?) and work from there.  Procedure in FSM
Its OK to stab the throttle quickly to get the idle down so you dont wrench your neck
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #3 ·
Oh okay, that makes sense. Wanted to make sure i wasnt dojng anyhing wrong. Pretty sure its the holly 2280 because everything is stock but i can check tonight.
 

·
Registered
Joined
·
13,500 Posts
agreed , if you can post a photo of the carb it will help
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #5 ·
Hey guys, finally getting back to this. I couldn't see a part ID on the carb but can you tell what kind it is by looking at it? I believe it needs a nice adjustment. Stumbles pretty bad when cold after stabbing the gas. I understand the engine needs to warm up and it purrs once warm. Is there an adjustment that can be done to make it idle better when warming up?


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
13,500 Posts
yup see the arm attached to the choke plate ? see the zig zag link going down to the cam / step plate that the idle speed screw contacts ?
O.K chokes can ONLY be adjusted when engine is COLD , you get 1 shot at it , then you must wait like over nite to try again . This happens and was considered "normal" you can not drive into a shop and have your choke adjusted , it must be left to cool . 
that said , do this for us , after an overnite cooling , remove air filter , step fully on throttle , and take a picture of the upper plate in throat of carb ( choke plate) so we can see how much it closes when cold . Then start the engine, "goose" the gas ounce , and take another pic . let it warm and take the 3rd pic  .

this will allow us to "see" fully cold , running cold , and fully warmed . positions . It would be really great IF we could see that choke cam and the screw during these 3 conditions as well .  if you use a P/C and click on photo it should enlarge to see it .
 

Attachments

·
Registered
Joined
·
240 Posts
Discussion Starter · #7 ·
Okay great info. Thanks for explaining. I did drive the truck this afternoon so what I’ll do is leave it overnight then after work tomorrow I’ll go through the steps you suggested and post the photos here.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
13,500 Posts
ok , btw the pic I posted shows an earlier carb , it does not show the electric idle solenoid your has . what that on yours does , is set the warm idle when the key is "ON" but when you switch key "OFF" it allows the idle to drop to zero , fully closing the carb when shutting motor off .  That helps prevent  " run- on "  where the motor keeps running/chugs to a stop after you switch it off ..  not much to do with choke / high cold idle ... best pic I have ...
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #10 ·
Alright! So I believe I did the test correctly. The plate didn't move at all when engine off cold at WOT.





Then this next part was tricky because it kept stalling but here is the engine running cold.





Then the engine running warm.





You can definitely see on the side view the plate moves towards the cab a few centimeters by the time it's warm. Not sure what the correct adjustment should be. Or if this is pretty close already. The biggest thing is it stalls about three times before getting going when cold. If I pump the gas it stalls right away if I let it sit it chugs for about 10 seconds then stalls. Once warm it purrs.

Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
13,500 Posts
the choke plate should close if you depress the pedal and release when the motor is cold/NOT running . The choke high idle screw should THEN be ON that eccentric "cam" , at almost its highest step .  it is not .
engine off cold , open the throttle , then check for any binding of the linkage attached to the choke plate shaft , if you find its free , then I'd replace the choke "stove" / choke "pull off " which ever name its called there . It is located on the passenger side , bolted to the intake manifold , with a rod comming up attaching to the choke plate shaft .

How it "should " work , pass side , stove is a Bi-metalic spring heat/cool makes it wind up /unwind , pulling that rod, closing the plate , vacume can also attached to that side of plate makes it open "some" when the engine does start and vacume gets to that can . driver side of choke plate shaft has linkage that drops down to that cam/idle screw , cold it moves the cam so the high idle speed is about 1100-1500 rpm , as the bi spring heats it moves the shaft/plate toward open , the cam drops down that high idle screw doesn't touch anything , the electric idle solenoid  takes over .  First thing to do is make the Bi spring "stove" work by replacing it ( time / use wears them out , they move less and less ..)  then if you say its reving I suspect someone has cranked the high idle screw IN to compensate for the defective stove , you may have to back it out ... first r/r the choke pull off/stove thingie . Yours appears to be 1 bolt /tab style right next to carb base on pass side of intake manifold .
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #12 ·
dodge82273 said:
the choke plate should close if you depress the pedal and release when the motor is cold/NOT running . The choke high idle screw should THEN be ON that eccentric "cam" , at almost its highest step . it is not .
engine off cold , open the throttle , then check for any binding of the linkage attached to the choke plate shaft , if you find its free , then I'd replace the choke "stove" / choke "pull off " which ever name its called there . It is located on the passenger side , bolted to the intake manifold , with a rod comming up attaching to the choke plate shaft .

How it "should " work , pass side , stove is a Bi-metalic spring heat/cool makes it wind up /unwind , pulling that rod, closing the plate , vacume can also attached to that side of plate makes it open "some" when the engine does start and vacume gets to that can . driver side of choke plate shaft has linkage that drops down to that cam/idle screw , cold it moves the cam so the high idle speed is about 1100-1500 rpm , as the bi spring heats it moves the shaft/plate toward open , the cam drops down that high idle screw doesn't touch anything , the electric idle solenoid takes over . First thing to do is make the Bi spring "stove" work by replacing it ( time / use wears them out , they move less and less ..) then if you say its reving I suspect someone has cranked the high idle screw IN to compensate for the defective stove , you may have to back it out ... first r/r the choke pull off/stove thingie . Yours appears to be 1 bolt /tab style right next to carb base on pass side of intake manifold .
Awesome thank you for the explanation, man carburetors are cool! I will look into getting a new choke "stove or pull of" and replacing it and see if the idle goes really high at that point which then I will most likely ask for adjusting instructions as to make sure I do it correctly. Thanks!
 

·
Registered
Joined
·
13,500 Posts
yes , no problem , when you get that far just ask .
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #14 ·
dodge82273 said:
yes , no problem , when you get that far just ask .
Okay, so I think I did that original test wrong and didn't open the throttle completely open because I tried again when testing if anything was getting hung up and the plate kicked into a closed position. I will take some more pics tonight. However, all of those pieces mentioned before seem to be working correctly or at least moving smoothly and accordingly. With that said, would there just need to be an adjustment on the idle screw?
 

·
Registered
Joined
·
13,500 Posts
glad you caught that , did the vacume can pull the choke a little farther open ounce it started and you "goosed " the gas ounce ? if so what "step" of the high idle cam is the high idle screw resting on ?

after all this you will still need to know that a little warm up is ok , that you can't expect peak performance while its cold , but it should stay running .cold ... and you should be able to drive normally 
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #16 ·
dodge82273 said:
glad you caught that , did the vacume can pull the choke a little farther open ounce it started and you "goosed " the gas ounce ? if so what "step" of the high idle cam is the high idle screw resting on ?

after all this you will still need to know that a little warm up is ok , that you can't expect peak performance while its cold , but it should stay running .cold ... and you should be able to drive normally
I will check this when I get home and do the test over again. I'll post some pics of my findings, and yea I know with the carbureted fuel/air system it will need some time to warm but yes exactly, trying to get it to not stall while warming up. Like 10 seconds after motor is ON.
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #17 ·
Okay! So completely cold the idle screw was on step number 3 of the quarter semi circle piece that zig zag piece is connected to. The choke plate looks closed. See photo





Okay and when started up cold after a punch of gas the choke plate opened way up and the idle screw is no on top of the semi circle. I guess this is called step 0





Also, I noticed when fiddling with that step quarter circle piece before starting the engine the first time that it was pretty easy to wiggle onto another step and this time starting it up there was no stall after punching the gas once. I'm wondering if maybe that's the issue. Maybe on a step that doesn't let enough air in?

This is it warm. Nothing looks to change except that the electric solenoid gets close to the throttle.



Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
13,500 Posts
;D ;D ;D you did very well . doing a choke adjustment via internet ? with your photos/ descriptions its working .

O.K. the high idle screw appears to be so far "IN" that the spring on it is squashed , that is not "normal" it will have to be backed out ... eventually , but I'm ahead of myself there . it appears that where the screw lands cold/off is good , but it seems like after the first goose of throttle , that vac can pulls the choke OPEN too far , it should still be a little more closed , and the screw should still be ON that cam .
2 possibility's why ...  1 the choke stove is weak / tired / wore out .    2. the vac can's zig zag linkage TO the choke shaft is not properly adjusted ( too short ) .
it appears in the photo that the zig zag link from the vac can to the choke shaft is not , umm , flat , it looks like it may have been "adjusted" ( done by bending it to shorten or lengthen it )  at one time . In any case you can Carefully bend that link to make it NOT pull the choke SO FAR open when you first goose the gas pedal .
so we are clear this is the passenger side , top rear of carb . an S shaped link from the choke shaft to a vacume can .    it can be a delicate operation with pliers / common screwdriver .  attention to detail .

sadly I cannot gauge or describe the strength/condition of the choke stove ( hands on learned thing) from a photo . so start by adjusting that link and THEN the high idle screw ( back it out ) to get about 1100 -1500 rpm , (a quick hummmm not a racing down the road roar )  ;D

 
 

·
Registered
Joined
·
240 Posts
Discussion Starter · #19 ·
All my photos are taken from the drivers side so the zig zag arm you’re referring to is on the other side of the carb (passenger) connecting to the choke stove not the one that is close to the idle screw?


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
13,500 Posts
NOT the idle screw side , NO . passenger side , rear of carb, the vacume can link that goes to the choke shaft . your overhead pics show it .
 

Attachments

1 - 20 of 29 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top