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78 Dodge d150 carburetor adjustment questions

R

Rude Robert

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S. California New home in Keene, Tx
Hi I have new rebuilt carburetor 2 barrel and a new choke thermostat too. I have been driving the truck for while now and I have not had the chance to adjust the choke. The choke plate if fully closed and in the mornings I have to use starting fluid to get it started, after that I can start it up just fine. My idle is okay but it fluctuates up then it will go back down when its warming up. I notice after I have been driving it some 34 miles both ways to work, when I stop at a red light the idle is high and doesn't go back down. When I turn off the truck and restart it, the idle is normal until I give it some gas then it stays up and wont go back down until I turn of the truck again. Would not having the choke adjusted be the cause of this? The old choke thermostat had some bends in it to adjust the carb, but the new one is just straight for now. I have replaced the carburetor before had never had this idle problem although have was always using the old choke thermostat. After church today I go back out there and work on it, I just wondered if anyone has some suggestions for me on this. Thank you for your help, Robert
 
Check the accelerator pump to see if it's squirting fuel when the throttle is opened. That would cause the hard start. High idle could be a vacuum leak, but is the throttle coming all the way closed?
 
Thank you for your reply, yesterday after church I was going to try and get out there but we are have a cold front coming in and is here. The temperature started dropping very fast and it was like 34 degrees at 1200. I couldn't that at all and currently it has been 28 at 1130 her on Monday. The airports are canceling flights too, it is too cold lol. As soon as it warms up I would go back out there and look, I think I can spray wd40 around the carburetor to help find a vacuum leak too is this correct? I know that fuel is spraying in there as I looked at it when I first put the carb on there and I will check again too. I am not sure what you mean about the throttle coming all the way closed, means? The throttle return spring that I put on there is way stronger then the old one, the gas pedal is way harder to depress then what I am use to, not sure if that is what you mean or not.
 
34? Cold? I wish we would get up to 34... Currently single digits here. Will be below zero tonight again
 
When the throttle is closed it will be against the stop screw to set the idle speed
 
Single digits lol, we had that a couple of months ago, peoples pipes were breaking so we had to keep our water dripping to stop them freezing. That is too cold, for sure. This is my first chance to go work on it and its about to rain so I need to get out there lol
 
Why do you say that? They are barely open at idle. Put a tach on it to measure rpm? Have to work back n forth between mixture adjust and rpm. Get a vacuum gauge and a tach adjust back n forth between mixture screws (little changes at a time) til it's smoothest and highest vacuum you can get then play with idle speed (rpm) screw.
Make sure you have the engine all the way warm so the choke isn't influencing how it runs
 
I meant my choke plate sorry, I am still having to use starting fluid to start it, but once it is started then I don't have anymore starting issues, only when it is cold. Yesterday I opened up the fuel jet a bit more and thinking I need a bit more fuel going into the carburetor and still had to use the starting fluid this morning. My last carburetor even though it was seeping fuel everywhere would start in the morning. This new rebuilt one doesn't yet.
 
Opened up the fuel jet? Huh? You mean idle screws? That won't change a thing for starting.

When the motor is dead cold next time, take the air cleaner housing off, grab throttle shaft and snap it wide open, let it shut and watch the choke butterfly, see what it does. Does it snap shut?
 
I am just able to figure out my password lol. I now have it so it just keeps me log in. A lot have happened and the truck wasn't running for a long time and it wouldn't start. I went through all the electrical systems and found my issue. I am still having the hard start issue and the idle when adjusted, to the right idle around 600 to 650, when i put it into drive it is barely keeping the truck from stalling. Forget about reverse it just dies unless I keep my foot on the gas to and brake to get the idle fast enough from stalling. I have to put the idle high enough to keep it from stalling in reverse which I can do it's really not too high. It is after driving for some time that the idle when i put it into neutral that the idle is pretty high. If i get stuck in traffic it seems to want to stall so i have to put into neutral then back into drive. I never had this problem at all with the any of the rebuilt carbs from Oreollys auto parts before. On the fuel jets i actually removed them and with a can of air blew them out and nothing was blocking them at all. I thought that the choke might be catching on the idle screw but it no where near to touching the cam. I am about to just buy another carburetor, as it never worked right from the beginning. Now my last remaining gauges that was working is starting to act up, and that is the temperature gauge, show it too high. I carry a temp gun with me to make that its really not that high. The block shows at 180 after driving 38 miles. Is there any company that makes a new gauge cluster to fit into the old dashboard by any chance?
 
Are you calling the idle adjuster screws the "idle jets"? Have you had a vacuum gauge and/or a tachometer on the engine and tried to adjust those screws? Ow high and how steady was the vacuum gauge needle/ did the tach jump around?
 
Hi. I removed the jet screws which on my truck are to the front of the carb. The idle screw and the screw for the choke idle are next to each other on the other side, basically. I don't have a vacuum gauge currently, It was lost in my move to Texas a few years ago. Honestly though, I never used it for the carb. I was in California and they are strict on the smog logs and the timing has to be correct as they want the old cars off of the road. I would do everything needed without one, I would set the idle with the timing light and have the idle set. I could get running pretty smooth even with the rv cam that I had put in there, when the engine was rebuilt. I had also the timing chain removed and now it is the gear type so that there is no timing chain.
 
Ok so you do seem to know the differences between idle mixture screws and idle speed screws. Can't know what you know unless I ask .. and you have a gear drive in there?
Overkill for a street engine but cool
Do you have a remote tach? You can sorta do the same as with the vacuum gauge, as just like the vacuum gauge adjust the mixture screws so that the tach don't jump around, get the steadiest reading you can.
I have a variable advance timing light that shows rpm when I don't pull the trigger, I usually have both that and the vacuum gauge hooked up together when I dial in the carb.
 
If your gauges are not working and the temperature gauge is maxed that would indicate the voltage limiter may no longer be doing its job. Take a test light and ground it to the engine. Pull the temperature gauge wire and insert the test light probe. If the limiter is working correctly the test light will flash off and on. If not replace the limiter.

It doesn't sound like the choke linkage is set correctly. Which carburetor did you get Holley or BBD? O'Rielly's is good about maintaining purchasing records. It's quite possible they may exchange the carb for another one. These two-barrel carbs are known to have top cover vacuum leaks. Covers warp.
Have you gotten the choke thermostat set correctly? With the thermostat hot it should just be holding the choke open. Then check the other carb linkage.
 
Hi i didn't know about the temperature gauge test. I didn't know about this voltage limiter test. I assume that I am pulling it off from the the plug correct? I called them and it is this one and I bought it back in December 22.

Tomco Carter 2BBL Carburetor - 2-545.​

 
I put on a new(rebuilt) carburetor on today. It is a little different and I am not sure why.

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Different as in how?
Probably a different "carb number" than what you had. Same model carb but they can have different numbers of vacuum ports.
 
the top picture is the old carb and there is no attachment on the bottom for another spring. the second picture had an extra vacuum connect that I plugged, the third picture shows no vacuum. I need to attach the other picture lol

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