At my wit's end

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Thanks for the info. I've thought about changing the carb over but figure if I am going to go through that I will just switch over to EFI. It seems like the springs really "should" fix the issue and get things running. HEI stuff should be waiting for me when I get home so I am going to make a stop at the parts store and see if I can find the springs I need.
 
Thanks racehog. I actually bought my rebuild kit from the same site but it came with the diagram for the older 1920 model. I was wondering why it would need a spring between the pump diaphragm and metering block like the older model did (since the spring on the diaphragm shaft should take care of that mechanism). Looks like I just need the float spring and the baffle. Part of me wonders that since I am missing that baffle if the fuel is coming through the needle at enough pressure to push the float down. I didn't get a chance to work on the car this afternoon so will give it a shot tomorrow. If it continues to act up I'll order one of the floats. I'll also try and fabricate a baffle.
 
Baffle just calms the incoming fuel flow down....
Not sure on the spring for the float. But I was told once that the old floats were heavy? So ether way iv just always put them back in. Now I have done without the baffle before with out problems. I guess some guys just dont know how to get them to stay......lol
 
Got the engine to run over finally today. Has the float spring and the HEI stuff installed.Took a lot of pedal pumping to get it to fire but then once it burned off the excess gas it idled pretty fine. I dropped it into gear and it idled fine there too. I let it idle for awhile and after maybe 7 minutes it died. Looked like it was flooding the carb so I adjusted the air/fuel mix screw anf tried again. Seemed to last about the same time before dying. I adjusted a couple more things and it seemed to be idling better so I decided to take a short drive down the street. I realized as soon as I hit the gas pedal that the timing is way off as it just sound terrible as I pressed the gas. It would go, but not fast, and sounded like crap. Need to get a timing light to adjust things. Hopefully that's it.
 
Did you replace the hose back at the fuel tank?

Pull somemore timing back in it... it will ether smooth out or start missing...
 
Tank, hoses, lines, and pump were replaced by the previous owner. I checked for garbage in the line after rebuilding the carb and it is all clear.

After reflecting on this more last night I think the cap I put on the new dizzy isn't sitting right. I vaguely remember the old dizzy had the same issue with this cap so I'll throw on the other one I have when I get home. If that doesn't work out I'll go pick up a timing light this weekend.
 
Pulled the dizzy this afternoon and moved it one tooth over and put a different cap on it. I turned the key and it fired right up. I tried adjusting the timing to get it right and once it idled ok I revved the engine to make sure it didn't die. Once I got it to not die while revving I decided to take it for a drive. I got it about halfway down the block when it started to stumble while holding the gas down. Eventually it died.I started it back up and it just seemed to get worse and worse. Once I got it home I tried adjusting the timing and playing with the air mixture but nothing change. Eventually it just stopped turning over. Only thing I can think of at this point is the HEI heatsink I made isn't doing its job well enough. I am going to see if it turns over again once everything cools down which would probably answer that. HEI module is out of the cheap HEI dizzy I have on my Ranchero too, so it could just be the chinese junk. Going to pick up a new proper one this weekend regardless.
 
Yup. Think I cooked my HEI module. Went to try it again and once everything cooled and nothing. I have some server style heatsinks lying around so i'll modify one to work and grab a new one once I get paid.
 
Hmm,sure seems like it might be a sinking float... If the float is made from phenolic material it is notorious for fuel soak. This eventually makes the float too heavy and it sinks,causing the symptoms you describe. Find a brass float and give that a try. Heck even if theres a brass float in there now,replace it...even those can develope leaks.
 
Did you make sure to apply heatsink compound between the module and the heatsink?
 
Yes I used heat paste. I didn't think about the float being the issue. The floats for the 1920 only exist in the phenolic material I believe and they aren't exactly easy to come by since they stopped making them. I would think that the spring would counteract the sinking, but I could be wrong there. Going to replace the HEI module anyway as I want a better quality one ultimately. I'll check on the float tomorrow though.
 
I doubt the HEI module overheated. In the GM distributor, they just bolt to a plate of aluminum, so your setup should run cooler. Did you run a ground wire from one of the mounting screws to a solid ground? Doesn't sound like you tested for spark. I use a $4 Harbor Freight in-line neon light.
 
I checked ground and it seems to be fine. It is just going to the body right now. When I swap out the HEI module and put a new heat sink on it (current one is just a make shift piece of scrap sheet metal anyhow) I'll put a proper ground on over to the alternator ground.

PM'ed Dan to see if he still has any NOS 1920's lying around. If not I'll just get one of the floats from Walker, which is way cheaper than any of the parts stores list it for direct from their site.
 
Did you use the dielectric grease under the hei module? I know when replacing the module in my G.M truck the instructions specifically said to use the grease or the module would fail..
 
Yup. Applied the grease. It isn't a dielectric grease but a heat compound like found on computer CPUs. From what I've been reading about he problem I'm having it does sound like it is probably the carb. Hoping Dan has the right replacement/NOS 1920 and I'll just swap out the whole thing. Otherwise I'll try the new float and go from there. I'll still grab a new HEI module or two this weekend since I need one for my 67 Ranchero too. Heck, I might have that car running before the Dart at this point.
 
I am a dork. Yup. Had a flash yesterday at work that I might have put the fuel needle in backwards when I rebuilt the carb and somehow missed that every time I adjust the float. I pulled the fuel bowl off when I got home today to find it bone dry and yes in fact the fuel needle was in backwards and pushed in enough to allow almost no fuel into the bowl. I reversed it and tried to start it. Once I got enough fuel into the carb it fired right up. I played with the throttle and let it rev for awhile to see if it bogged down, but it didn't. I let it idle for a little bit while I adjusted the timing a little and then took it for a test drive around the block. It seemed to bog a little after holding the gas for an extended period of time, which tells me the float isn't opening like the spring isn't letting the float drop or something. I'll adjust it tomorrow and getting the timing a bit closer to right.
 
BillGrissom said:
Setting the points gap with a feeler gage is just to get you close. You should use a "dwell meter" to get it correct. I have the Sears tach/dwell/volts meter, which you see on ebay or garage sales. Points aren't fun, especially on a slant. You said you were going HEI anyway. Did you get an electronic distributor for that? If not, a Pertronix in your existing distributor is probably easiest.

Your problems sound exactly like how my 69 slant ran for years, though many things could cause it. In my case, it was the carburetor. The 4th Holley 1920 finally made it run fantastic.
Click to expand...

Never knew this.Been only gapping points my whole life.
 
Dielectric grease and heatsink compound are 2 VERY different things. Heatsink compound transfers heat, dielectric insulates it. Do not confuse those two materials.
 
Can you get a FSM for a 73 Dart? It would cover your current 1920 carb in a lot of details so you can be sure stuff isn't missing or installed backwards. And I have to ask, why not swap over to a factory electronic ignition? Your points distributor's shaft bushing may be worn out, after years of having the pressure of points rubbing against the center cam, causing the whole thing to wobble. A factory electronic distributor, even a used one, will most likely not have that problem. Yes it's more stuff to swap over (wiring harness and changes to it, ecu, etc.) but it works, and can be taken off any 73 and later non lean burn slant six vehicle. And if you have a manual it can be used to troubleshoot it.
The 1920 is a good carb. I'd check the throttle shaft for slop - if there is any it's a potential vacuum leak source. It can be re-bushed, or in a pinch, the carb can be disassembled and you can center punch all around the shaft opening to tighten it up some. There's also nylon strips in some rebuild kits that can be inserted around the shaft and the housing to tighten it up some.
Your pine sol dip may have worked well to clean it up. Did it also strip off any of the yellow anodizing?
Some guys on here mentioned checking your charging system. On any old mopar of that age I always check the connections from the alternator and the battery that go thru the bulkhead connection at the firewall. They are usually green and can cause problems. The male connectors can be removed from the plug by pushing them sideways parallel to the connector ( --- <-- push this way...) wire brushed, greased, spread back out and pushed back in. Look at the heavy black wire from the alternator and the heavy red with the fusible link from the battery.
 
Have you ran the valve lash on that engine yet? The reason I asked is the '73 I picked up recently pulled the same stunt today.

It ran fine until it warmed up, then would waver up and down at idle. I turned it off and let it sit several minutes, and when I restarted it, it would idle down and sound like it was dropping one or two cylinders and then stall.

I adjusted the valves this evening and now it seems to be running smooth as silk. You may want to go ahead and do that before pulling your hair out over other ideas.
 
I opened up the fuel bowl again yesterday to readjust the the float and got it to run decently. I tried setting the timing by a timing light but the AC stuff is in the way of getting a good look at the timing markers. I need to setup some markers/pointers on the alternator side so that I can get it right, but it is running properly now so I am not super worried. I replaced all the vacuum lines between the dizzy, carb, and CAB which helped a lot too. I freed the seized heater valve thingy using some PB Blaster and elbow grease. Once all that was buttoned up I took it for a decent drive around the area and didn't have a single issue. I took a couple of the corners a little harder than I normally would to see if it would stall or bog, but it didn't. Car now starts up with very little effort either hot or cold.

I went with the HEI because I already had a lot of the components lying around the garage minus an electronic dizzy. I ordered a refurbished one, which looked more like a return than a refurb, but it works. Yes heat compound and dielectric grease are two very different things. I build a lot of PC's so I know what it is any why it is used. My electrical components were pretty sparse when I was installing the HEI stuff so it was done in a more proof of concept manner versus a finished install design. I've purchased some things and ordered some others that I will need to "do it right" in a few days.

I do have an FSM for the 66 and one for the 1920 carb. It really was a pounding my head against a wall moment when I saw that I screwed that simple thing up. Its been a couple of years since I've rebuilt one though. There wasn't any of the anti-corrosion stuff on the carb before I put it in the PineSol. This was one of the reasons I coated it with WD40, though I've heard that lithium would have been better.
 
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