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Looking for advice for cold starting 318 engine

FallingApart4dr

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Hello everyone, hopefully, im posting this in the right area.

I'm a 16 y/o highschooler and recently bought my first car, A 1967 4-door coronet. I've been giving it a lot of TLC as it's been sitting for quite a while and the past owner didn't treat it the greatest
frown.png
. The biggest issue I've been having with the car is the cold start. I've re-tuned the carburetor, dumped about every engine and carb cleaner under the sun into the engine & carb, and honestly, the cold starting has seemed to have gotten worse than from when I first got it. Sometimes it starts after only 2 or 3 cranks, but today one time it took almost 15-20. Sometimes the engine will fire for a second and then die right after.

I have a few ideas on what it may be and I was looking for your guy's advice.

  • Could it be the fuel pressure? It had a fuel regulator prior which I removed and replaced with a fuel pressure reader. The first time I ran the car, it jumped around from 6-7. The next time I ran it, it jumped around from 1-3. I thought the gauge was broken, but the 3rd time I started the car it stayed at a steady 6, which is what I read was the best fuel pressure for the Coronet.
  • The harmonic balancer shows the top dead center at 34 degrees advanced. When it originally started cold and I was looking at the timing, it seemed to jump occasionally to being advanced until the car warmed up and it settled at the top dead center. Is there anything that you think could cause this?


Some extra info about maintenance already done since purchase if that helps:

  • Changed oil
  • Fuel line/filter/pressure reader
  • Carb tube-up (hoping to rebuild eventually)
  • Bunch of engine bay cleaning/additives
  • Some other stuff but I don't believe it could be related to the issue.
Thank you guys for any advice in advance!
 
You have a bag of worms here for starters. First thing pull the air cleaner and post pictures of the carb.
 
Ok, same issue on my Cordoba. After a few days, the fuel will evaporate and will require a squirt of gas in the carb. Does it happen after the car is unused for any length of time ? Is the choke operating properly ?
 
You need a factory shop manual. Buy the cheapest (and rattiest) manual on eBay. It will tell you how to set the choke and carb for proper cold starting. I think there is one online for free.
 
I second Sam's advice!!! First purchase should have been a shop manual. There is a web site known to many where you can download the shop manual for free. Hopefully someone will see your post and provide that info.
 
Hey, we'd all love to see some pics of the car. Post an official 'howdy' in the Welcome Wagon section. We like 2-doors, more-doors, station wagons... they're all beautiful.
 
not sure why you need a fuel pressure reg. factory pump is good to go without one!check your fuel line for corrosion and possibly pinhole!, good fuel? remove breather and check the accelerator pump for a good shot when is throttle opened and then make sure the choke plate is closing almost fully!
dumping carb cleaner down the carb does nothing for the carb! it needs to come apart to be cleaned!
 
check your fuel line for corrosion and possibly pinhole!,
Start at the tank and check the rubber hoses back to front. The web site Gold Rush stated is "My Mopar"
 
Last edited:
Start at the tank and check the rubber hoses back to front. The web site Gold Rush stated it "My Mopar"
Pull the tank and see how good or bad it is and the pickup in there it should have a sock filter on its end. Yout gas gage works off that thingy. Replace the rotted rubber fuel hose at tank. Blow air from that hose thru steel fuel line to fuel pump WITH its line taken off!!! Now to carb!! Like said, get a FSM !
 
Get the factory service manual, it will help with SO MANY things. I fought with my OEM 2BBL on my daily driver '70 383 for a couple years. It revolved around two issues, the choke operation and the accelerator pump operation. I suspect you are having much the same issues. Choke operation can be a very tricky deal. A plugged/carboned up heat passage may be an issue?
 
Get the factory service manual, it will help with SO MANY things. I fought with my OEM 2BBL on my daily driver '70 383 for a couple years. It revolved around two issues, the choke operation and the accelerator pump operation.
Good morning everyone, I'm gonna use this to try to answer most of the posts. Thank you so far for all your advice!

First off, I have a physical hard copy of the FSM and Body/Electrical assembly manual. The issue is that it only talks about tuning the OEM carburetors. The carb that came with the car is a Holley 500 CFM Performance 2BBL Carburetor. I tuned the float & fuel-air mixture using a general guide. The engine sounded leagues better after that tune-up. I then kept messing around with the air/fuel mixture to get the best vacuum pressure. Maybe that's where I went wrong. One thing I also forgot to mention before was that I replaced the sparkplugs and distributor wires so I'm pretty sure they can't be the cause at all. Used FSM to make sure I got the right sparkplugs.

Pull the tank and see how good or bad it is and the pickup in there it should have a sock filter on its end. Yout gas gage works off that thingy. Replace the rotted rubber fuel hose at tank. Blow air from that hose thru steel fuel line to fuel pump WITH its line taken off!!! Now to carb!! Like said, get a FSM !
I'm planning on pulling the tank soon, I know it needs a replacement because it leaks. I think it might be that the seal around the sending unit is rotted.

Ok, same issue on my Cordoba. After a few days, the fuel will evaporate and will require a squirt of gas in the carb. Does it happen after the car is unused for any length of time ? Is the choke operating properly ?
Before I cold start the coronet I always give it 3 pumps of gas before ignition. When the engine is hot it fires and runs like a dream.

not sure why you need a fuel pressure reg. factory pump is good to go without one!check your fuel line for corrosion and possibly pinhole!, good fuel? remove breather and check the accelerator pump for a good shot when is throttle opened and then make sure the choke plate is closing almost fully!
dumping carb cleaner down the carb does nothing for the carb! it needs to come apart to be cleaned!
I'm not sure why it was there either. The guy who owned the car in the past has done some weird things in the engine bay. I removed it and swapped it out for a fuel pressure reader valve. I just noticed that in the mornings the fuel pressure went to 0. I think it could also be the diaphragm in the pump is worn out. Fuel could be leaking back into the gas tank. It could potentially explain why I have to crank it a bunch to get fuel back up to the carb.

Here are a few videos I took (hopefully video links are allowed). I couldn't get many because shortly after this my power steering return line decided to rupture on me
frown.png


Cold start: (In most of these you can hear how the engine tries its best to stay alive)

Another cold start:

I'm not sure why it's so quiet in this one but this is another example of the engine trying to stay alive.
If it's able to run for about a minute it has no problem firing up again and it begins to sound way better than these initial starts.

Here's what the exhausts sound like right after a cold start:
 
It looks like a manual choke and it seems to have the fast idle cam disabled.
See if you can adjust the fast idle to come on when the choke is less than 1/4" open.
Your idle speed with the choke set is too low.

Close the choke fully when stone cold and when cranking with your hand on the lever pull open slightly as soon as it fires. A manual choke is a tricky thing and yes you may have some issues with fuel draining back out when sitting like you described. Try cranking for about 5-10 seconds, then 2 or 3 pump shots, set choke fully closed wait maybe 5-10 seconds then crank it to start. (Along with the other suggestions)
 
You need to goose the gas pedal to get it off of idle so things can get going. Pumping it before you crank it does nothing if the fuel bowls are empty. While cranking, pump a few times and once it fires, goose the throttle to keep it going. It will settle out and get better once it is warm. It should start fine like you said once it is warm. One major thing you have to remember is that this is not at all like fuel injection on newer cars. It will not start and idle like a newer car. You need to goose the throttle to keep the engine running, or at least so the fast idle cam engages to keep the idle up. You don't need to floor it, just goose it for about 15 seconds or so to keep it running. You will get the hang of it... :thumbsup:
 
All I can say is it looks like you have your hands full.:)
 
I think it sounds pretty good at the tailpipe and the super bee tips are a nice touch.
:thumbsup:
 
Hello everyone, hopefully, im posting this in the right area.

I'm a 16 y/o highschooler and recently bought my first car, A 1967 4-door coronet. I've been giving it a lot of TLC as it's been sitting for quite a while and the past owner didn't treat it the greatest
frown.png
. The biggest issue I've been having with the car is the cold start. I've re-tuned the carburetor, dumped about every engine and carb cleaner under the sun into the engine & carb, and honestly, the cold starting has seemed to have gotten worse than from when I first got it. Sometimes it starts after only 2 or 3 cranks, but today one time it took almost 15-20. Sometimes the engine will fire for a second and then die right after.

I have a few ideas on what it may be and I was looking for your guy's advice.

  • Could it be the fuel pressure? It had a fuel regulator prior which I removed and replaced with a fuel pressure reader. The first time I ran the car, it jumped around from 6-7. The next time I ran it, it jumped around from 1-3. I thought the gauge was broken, but the 3rd time I started the car it stayed at a steady 6, which is what I read was the best fuel pressure for the Coronet.
  • The harmonic balancer shows the top dead center at 34 degrees advanced. When it originally started cold and I was looking at the timing, it seemed to jump occasionally to being advanced until the car warmed up and it settled at the top dead center. Is there anything that you think could cause this?


Some extra info about maintenance already done since purchase if that helps:

  • Changed oil
  • Fuel line/filter/pressure reader
  • Carb tube-up (hoping to rebuild eventually)
  • Bunch of engine bay cleaning/additives
  • Some other stuff but I don't believe it could be related to the issue.
Thank you guys for any advice in advance!
I wouldn't do half of what was suggested here. You need to take the air cleaner off and look down the carb as you open the throttle. You should have a steady squirt from the accelerator pump and the choke butterfly should go closed (or near closed) and stay closed under spring pressure. My guess is that if there is no acc. pump squirt the fuel has evaporated. It doesn't take long. Overnight can cause issues. 2 or 3 days and you will have to crank it a lot to fill the carb back up. The choke must close on cold start and start to open when the engine fires. If it doesn't, you need to figure out why. With no photos we are just guessing what you have, what works, and what doesn't.
 
When it starts cold, the fast idle speed setting is way too low. You need to adust the "fast idle" settings. Fast idle will keep the rpm up while the engine is warming up. Once warmed up and you touch the accelerator, the fast idle cam should release and then you'll be running at "curb idle" speed. Maybe this video will help as far as adjusting fast idle.

 
When it starts cold, the fast idle speed setting is way too low. You need to adust the "fast idle" settings. Fast idle will keep the rpm up while the engine is warming up. Once warmed up and you touch the accelerator, the fast idle cam should release and then you'll be running at "curb idle" speed. Maybe this video will help as far as adjusting fast idle.


The holley 500 2- barrel was likely a heat stove with a bi-mettalic spring not an electric choke shown in the video. Late 70s also had an electric heater in conjunction with the old spring.
 
The holley 500 2- barrel was likely a heat stove with a bi-mettalic spring not an electric choke shown in the video. Late 70s also had an electric heater in conjunction with the old spring.
500 2 barrel's had a manual choke.
 
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