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+--- Thread: Looking for advice for cold starting 318 engine (/showthread.php?tid=4125)
Looking for advice for cold starting 318 engine - FallingApart4door - 01-20-23
Hello everyone, new member here.
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
. 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. 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!
Looking for advice for cold starting 318 engine - 67440Dodge - 01-20-23
Based on what you've described, I'm thinking the motor may have the original nylon teeth on the timing gear for the camshaft, and they have started to break off, causing erratic timing. One way to check is to drain the oil, and look for small particles of plastic in them. Another is to pop the distributor cap, put a socket on the center crank pulley bolt, and rotate the engine in reverse. If you notice a good amount of time for the rotor on the distributor to turn, (it's hard to say how much because it's been awhile since I did it) it's a sign the nylon has started to break off. The only true way to tell is to pull the oil pan and look for pieces in the pan and the oil pickup tube, or the timing cover and look at the gear and see how much slop is in it. (might as well swap it and the chain while in there). If there are teeth missing, make sure you clean the oil pump pickup tube, as it's most likely packed with bits of the nylon teeth.
Don't want to scare you, but if the teeth break off enough to cause the chain to skip a tooth, that's called "jumping time". Which means the valvetrain is no longer in time with the pistons. And since a 318 is a interference motor, when this happens a valve hits the piston and at a minimum causes a bent valve, at worst, a busted valve in the piston.