Ready to shoot my 273

-
D

dartsixty7

Well-Known Member
Joined
Jan 3, 2011
Messages
48
Reaction score
1
Location
Kalifornia
I'm at my whits end concerning my 67 Dart with a 273/904. Engine & tranny have 30-35,000 miles on a rebuild previously done before I got the car, it also has been upgraded to electronic ignition and the regulator has been changed to one for the electronic ignition. I've put on a water pump/had the radiator rodded out about 5 years ago and just recently had the 2 barrel carb rebuilt, I also dumped the single field alternator and put in a duel field one for a 73-74 duster. I grounded the second field post. Here is the problem: The car starts and runs ok, it's when I have to come to a stop the engine idles down and some times will stop. With the engine hot it takes a couple of tries before it will start again. The engine also hesitates when I give it gas, but only when I'm driving, with it parked and in Park it takes the gas with no problem. I've advanced the timing and the engine runs good while idling, but when I put it in Drive it idles down and almost seems to want to stall out. Can some of you small block gurus give me some advice as to what I need to do. I really hate to have to spend money that I don't have and take it to a mechanic. Any help is appreciated. If what I wrote above doesn't make sense just let me know and I'll try to make it clearer.

Dan in Silicon Valley
 
you say you had the carb rebuilt, did you rebuild ir or did someone else do it?
who reinstalled and tuned it after the rebuild?
 
Just guessing... Timing too low, fuel level in the bowl way too high.
Disconnect the vacuum line to the spark advance in the carb and put a vac' cap on the carbs port. If you dont have a timing light, just turn the distributer slowly moving the vacuum advance in front of the oil sender.You're looking for 16 to 20 before tdc.
Now turn the engine off and look for fuel leaking down the carb and smoke like vapor coming out. If thats not present, good. Now move the throttle by hand and see if the very slightest movement will cause a squirt from the accerator pump on the carb.
If you have a aftermarket air cleaner check that it isn't sitting on/hitting the accerator pump lever or linkage when its bolted down.
Leave evrything as is and drive it. If you get a spark knock under load like up a hill you need to lower the timing in small increments until that goes away.
 
It does sound like a carb/fuel thing since it tries to stall at a stop.
I think Redfish has you on the right track.
Might want to chk the float level and needle seat too. (Really easy first step)
 
pull the valve covers and see if it has adjustable rocker arms....if it does then adjust the valves to factory specs then go back to the tuning process
 
After 2 years and hiring my carburator rebuilt, my 273 would not run correctly. I pulled the carb and tore it down myself and fount a pinhole in the float assy. The float would fill with fuel and sink to the bottom of the float bowl, allowing the raw fuel to overflow the carbutator and flood the engine. It was a difficult diagnosis but I was able to buy a new float from NAPA and I will never hire carburator work again. Good luck, Rat
 
All the advise is good that everyone has been giving you. If you have never adjusted the valves you should. If the engine has solid lifters it will be noticeable at idle and will be less noticeable at cruising speeds. (I'm sure the stumble is the carburetor). I'm not sure the dying at a stop is the carburetor but could be that or the timing. If it has a stromberg carburetor, throw it away, really! Get a little two barrel holly or a carter. One real easy check is the accelerator pump, it needs to travel below the float setting or an air gap between the gas in the bowl and accelerator pump will cause a stumble. Set the carb. rich it will at least give the engine the vacuum it needs (3 full turns both screws) then adjust it in just until the engine idle speed starts to drop and then back it back off 1/4 turn to 1/2 turn. The timing is initial and mechanical which sometimes is not enough to idle correct so that is when you add the vacuum advance and just add it at max setting first, (this is assuming the canister is adjustable with a 8/32 Allen wrench) then when you drive it it should be very nice at stops and at idle and you should be able to idle the engine down to the throttle plates just barely being open the correct way a carburetor works. And you will also know if the vacuum advance is to much when you cruise it on the highway it will surge if it is too much, then back it off a little. By the way the canister is full vacuum just cracked open 1/4 turn counter clockwise, the more you back it off, the more it backs off. If the engine pings & detonates at acceleration it has too much initial and or mechanical, back it off 2 degrees at a time. The 273 should run pretty darn good with 11 degrees initial, 28 to 30 mechanical. The vacuum is debatable at 35 to 50 degrees. Hope this helps you, we all go through the hoops to get these MoPar's and any other carburetor engine running good. They are all just slighly different, but one in the same!
 
I checked my motor manual and the 1967 273 is: Point Gap .017, dwell angle 28-32, breaker arm tension 17-20, advance starts 4 @ 500. full advance 17 @ 1900, inches of vacuum to start plunger 5-8, max adv. dist. deg. @ vacuum 13 @13. This is based on the 2 barrel engine. I'm posting this so you can see what type of settings it had in stock form which wont be much different set up totally electronic, it will just have a much hotter fast spark and wont need to be tuned up as often because the plugs will last longer and there will be no points to change. The valve settings are .017 Intake And .021 Exhaust hot which just means warm. And the best way to set them is on compression stroke following the firing order. This is based on factory equipment. If you think the cam has been changed from other than factory just set them at .022 & .022, it wont hurt it's performance, just a little more tick tick tick. Hope this has helped you!
 
65CudaFish said:
I checked my motor manual and the 1967 273 is: Point Gap .017, dwell angle 28-32, breaker arm tension 17-20, advance starts 4 @ 500. full advance 17 @ 1900, inches of vacuum to start plunger 5-8, max adv. dist. deg. @ vacuum 13 @13. This is based on the 2 barrel engine. I'm posting this so you can see what type of settings it had in stock form which wont be much different set up totally electronic, it will just have a much hotter fast spark and wont need to be tuned up as often because the plugs will last longer and there will be no points to change. The valve settings are .017 Intake And .021 Exhaust hot which just means warm. And the best way to set them is on compression stroke following the firing order. This is based on factory equipment. If you think the cam has been changed from other than factory just set them at .022 & .022, it wont hurt it's performance, just a little more tick tick tick. Hope this has helped you!
Click to expand...
The plugs gap at .035:burnout:
 
65CudaFish said:
I checked my motor manual and the 1967 273 is: Point Gap .017, dwell angle 28-32, breaker arm tension 17-20, advance starts 4 @ 500. full advance 17 @ 1900, inches of vacuum to start plunger 5-8, max adv. dist. deg. @ vacuum 13 @13. This is based on the 2 barrel engine. I'm posting this so you can see what type of settings it had in stock form which wont be much different set up totally electronic, it will just have a much hotter fast spark and wont need to be tuned up as often because the plugs will last longer and there will be no points to change. The valve settings are .017 Intake And .021 Exhaust hot which just means warm. And the best way to set them is on compression stroke following the firing order. This is based on factory equipment. If you think the cam has been changed from other than factory just set them at .022 & .022, it wont hurt it's performance, just a little more tick tick tick. Hope this has helped you!
Click to expand...

I think with electronic ignition and todays puppy pee fuel a lot of the factory specs dont apply.
I'm tickled pink with the way my 67 273 runs today but it wasn't easy getting here. Combination of crappy chineese ignition module ( blue box )
Bowl vent on the 73 model Carter 2 brl not opening, etc.. I found only 2 exhaust valves about .003 over spec. All others were just right. Another plus is The new FelPro rubber valve cover gaskets dont leak and there isn't any RTV on them at all.
Final setup is chrome box ecm, 19 btdc at about 900 rpm hot and in neutral. Vacuum advance disabled.
The curb idle adjust screw is hardly touching the stop. It wont idle any lower.
Bottom line, Keep screwing around with it. It might take a while but you'll find its sweet spot. Good luck
 
RedFish said:
I think with electronic ignition and todays puppy pee fuel a lot of the factory specs dont apply.
I'm tickled pink with the way my 67 273 runs today but it wasn't easy getting here. Combination of crappy chineese ignition module ( blue box )
Bowl vent on the 73 model Carter 2 brl not opening, etc.. I found only 2 exhaust valves about .003 over spec. All others were just right. Another plus is The new FelPro rubber valve cover gaskets dont leak and there isn't any RTV on them at all.
Final setup is chrome box ecm, 19 btdc at about 900 rpm hot and in neutral. Vacuum advance disabled.
The curb idle adjust screw is hardly touching the stop. It wont idle any lower.
Bottom line, Keep screwing around with it. It might take a while but you'll find its sweet spot. Good luck
Click to expand...
Yep that is what it takes, keep screwing around with it. Just be sure you don't go over the 35 degrees total timing that will cause damage. And the way to make sure of that is to set that first and leave it alone. I always set my 273 and 318 engines at 28 total and leave them there. But a 340 & 360 like that full 35 degrees even 36 in some cases which I call pushing it so I just set them at 35 and no more and at least they keep on running while I can fix the other things. And once that total timing is set you can note the initial and also hook the vacuum advance up because it cant hurt the engine. I like vacuum advance on the street because it keeps the torque from launching the car and the tires from burning:burnout: Tires cost allot now and well street is street and strip is strip. Not to mention cuts the gas cost virtually in half.
 
Ditto on the fuel level. I looked at a buddies No-va and it would idle for about a minute and start to sputter and die. His Holley blue pump was regulated wide open! So that was about 12 psi to the little Edelbrock which likes maybe 5. Flooding out. Also check the vaccum advance plate with a mighty-vac or some vacuum source and see if its actually moving or hanging up on its slides, That grease turns to hard varnish after about 30 years.
 
65CudaFish said:
. I like vacuum advance on the street because it keeps the torque from launching the car and the tires from burning:burnout: Tires cost allot now and well street is street and strip is strip. Not to mention cuts the gas cost virtually in half.
Click to expand...

I'm lovin the throttle responce I get now. I could actually spin a tire id I wanted to. Happy moparing.
 
with any engine go to the basic's first,the problem described by the original poster can be many things.....his year of 273 could have solid or hydraulic cam so check that first it will cause the same symptoms.....just sayin.....
pishta said:
Ditto on the fuel level. I looked at a buddies No-va and it would idle for about a minute and start to sputter and die. His Holley blue pump was regulated wide open! So that was about 12 psi to the little Edelbrock which likes maybe 5. Flooding out. Also check the vaccum advance plate with a mighty-vac or some vacuum source and see if its actually moving or hanging up on its slides, That grease turns to hard varnish after about 30 years.
Click to expand...
 
Thanks for all the help and replies. I advanced the timing to 20 degrees and turned the fuel mixtures screws out to 3 turns. After driving it yesterday morning to a show which did include freeway driving it ran better on the freeway, but when I pulled off and came to the first stop light it idled down and stalled. It took a couple of minutes for it to start back up. I had the same problem when I drove home. I'm thinking perhaps I need to tighten the fast idle screw a little to bump the idle speed and perhaps advance it 5 - 10 degrees more.

Dan in Silicon Valley
 
Set idle mixture with a vacuum gauge hooked up to carb. At idle speed (around 800 rpms) set idle mixture one screw at a time by turning screw in or out till you get the highest amount of vacuum, sometimes you will need to reset idle if it gets too high or low. If you have a stock or mild cam you should be able to dial in at least 12in or you have a vacuum leak somewhere (intake or carb gasket). Also try running it with vacuum advance unhooked and see if that changes. Are you setting total timing with vacuum advance unhooked and pluged at carb?
 
Sorry, I don't have a vacuum guage. I am setting timing by removing the vacuum advance from carb and plugging it and I also plug the line to the distributor. I'll have to call some friends to see if any of them have a vacuum gauge I can use. I'm also planning on installing a tach if I have time this weekend, if not then hopefully next week, unless I have to go to court since I have jury duty. Thanks for all the replies and help.

Dan in Silicon Valley
 
dartsixty7 said:
Thanks for all the help and replies. I advanced the timing to 20 degrees and turned the fuel mixtures screws out to 3 turns. After driving it yesterday morning to a show which did include freeway driving it ran better on the freeway, but when I pulled off and came to the first stop light it idled down and stalled. It took a couple of minutes for it to start back up. I had the same problem when I drove home. I'm thinking perhaps I need to tighten the fast idle screw a little to bump the idle speed and perhaps advance it 5 - 10 degrees more.

Dan in Silicon Valley
Click to expand...
With 20 degrees initial that allows for 15 degrees mechanical. What I suggest is setting the total timing and not worrying about the initial timing. Disconnect the vacuum advance canister and make sure all vacuum sources are plugged off. Hook the timing light up rev the car until the mark on the crank is fully advanced note the degree (I believe on a 273 you'll need a newer style timing light because the mark on the crank disappears because of the location of the timing marks on 273's) now adjust the engine timing to 28 to 35 degrees lock the distributor down and the total timing is set. With the vacuum advance see if it is an adjustable type with the 8/32 Allen wrench inserted into the vacuum line of the canister turn it all the way in until it bottoms out, then crack it back open just a little bit that will be full vacuum assist. Hook the line back up to full port vacuum, not ported vacuum. This is why it is probably dieing at a stop, you have the vacuum advance hooked up to ported vacuum and it only applies vacuum advance when you accelerate, hook it to full ported vacuum and you should be fine.:eek:ops:
 
65CudaFish said:
With 20 degrees initial that allows for 15 degrees mechanical. What I suggest is setting the total timing and not worrying about the initial timing. Disconnect the vacuum advance canister and make sure all vacuum sources are plugged off. Hook the timing light up rev the car until the mark on the crank is fully advanced note the degree (I believe on a 273 you'll need a newer style timing light because the mark on the crank disappears because of the location of the timing marks on 273's) now adjust the engine timing to 28 to 35 degrees lock the distributor down and the total timing is set. With the vacuum advance see if it is an adjustable type with the 8/32 Allen wrench inserted into the vacuum line of the canister turn it all the way in until it bottoms out, then crack it back open just a little bit that will be full vacuum assist. Hook the line back up to full port vacuum, not ported vacuum. This is why it is probably dieing at a stop, you have the vacuum advance hooked up to ported vacuum and it only applies vacuum advance when you accelerate, hook it to full ported vacuum and you should be fine.:eek:ops:
Click to expand...
One other thing I do when running vacuum advance is I splice into the line with a small vacuum filter, it acts as a little reservoir and regulator, kind of smooths things out:glasses7:
 
65CudaFish said:
well street is street and strip is strip. Not to mention cuts the gas cost virtually in half.
Click to expand...


The streets today are more like driving in a parking lot. Expect for the expressways you would think its mostly electric cars on the road, burnouts are unheard of--that's reckless now @ some places
 
I agree it is probably a fuel issue, though it sounds more like idling too lean than rich. I base that on my Holley Projection, where I can adjust the O/F with the turn of a knob. If the idle is turned too lean it will idle OK in Park but slow way down and want to die when you shift to drive. My slant six used to do that too until I finally found a good Holley 1920 carb (about my 4th try), then it ran as smooth as a sewing machine. Without a lean/rich indicator (O2 sensor) you are flying blind, so consider getting one eventually.
 
BillGrissom said:
Without a lean/rich indicator (O2 sensor) you are flying blind, so consider getting one eventually.
Click to expand...

Your not totally bind, once too lean you can feel it while driving, then richen it up a bit. For the secondary jetting go for highest mph in a run. Keep jetting up till power feels to drop then back it off 2--3 jet sizes. Gets you close with no 02 sensor

Right now something is way wrong, its not close at all. I agree its in the carb likely, floats are a good maybe, could be leaking, sticking or set wrong.
 
Dodge Freak, where do you get jets for a 2 barrel carb? I know about 4 barrel carbs but have never heard of re-jetting a 2 barrel one. With all the test equipment people are suggesting I get, perhaps it would be cheaper to take the car to a real mechanic.

Thanks for the help,

Dan in Silicon Valley
 
dartsixty7 said:
With all the test equipment people are suggesting I get, perhaps it would be cheaper to take the car to a real mechanic.
Click to expand...

You've gotten advice from one on this thread. Twice.
 
You must log in or register to reply here.
-

Back
Top