Logo
FULL SITE MENU

Chrysler 318 Kills After Warm Up

H

HIGGINS83

Member
I have a 30' Trojan with twin Chrysler 318's approx. 1978 or 1979. I need help, have been working on this for a year and would like to enjoy time on the water this year.

After warming up and running it will start missing between 1200 and 2000 rpm. Eventually will kill. Runs better at 1000 and over 2000 rpm, but will miss and kill after awhile.
Runs fine in neutral at all rpms, used to start right up in neutral after killing, now needs throttle to restart.
I have switched carbs to port engine, did the same thing. Replaced fuel pump, (Both Engines Are Off Of The Same Fuel Line) All new electronic ignition, new plugs, new distributor...don't know what else to try.
Any help would be greatly appreciated.
Higgins83 :confused:
 
I'm thinking crossed ignition wires, which is easy to with that lousy wiring setup the factory used on these engines..

Try this: Warm the motor thoroughly and idle it at 1,500 rpms. Using insulted pliers and gloves, pull one wire at a time from the distributor cap and listen to how the motor reacts. If it slows noticeably, put the wire back and continue on. And if you find two cylinders that don't react, swap those two wires and try the test again.


Good luck!

Jeff
 
Thanks but this was checked and is fine. It runs for 15 minutes fine, water temp. is fine and then it starts missing and will die. When it starts missing it runs better at 1200 to 2000 rpms, but eventually it will miss and die.
Thanks for your time.

David
 
I have done everything, New fuel pump, all new electronic ignition, new plugs, new distributor, coil..switched distributor from good engine, runs the same.
Could it be the Cam, and how would I check that? I just didn't want to think about that might be the case.
Thanks
 
I don't think, if it was a cam issue, it would change with engine temp. If I were you I would change coils from side to side. I know you said it was new but I know a guy who bought one a few years ago and it was bad from the start. Easy to do anyway and you're running out of options. One other thing you may try is to run a new wire from the ign. to the coil just to rule out a corroded wire.
 
Hmmmm? How bout a carb adjustment and timing when its warm


Figured Id take a stab


New Distributor? A whole new one or a cap and rotor

How good does the rotor come back when you flip
 
The carb was taken off of the good engine and put on the port and it did the same thing.
Whole new distributor, so rotor is fine.
Thanks for any suggestion. I need all the help I can get...
 
I'm having the same issue you are so I hope you find the problem, as it may solve mine. I'm not as far along as you in diagnosing though. I have 2 30 year old coils so I'm going to order a new one as soon as I get back from vacation.
 
Just be sure you get the RIGHT coils, Sammi. The one you want has "external resistor required" printed on it.

Higgins (that guy on Magnum PI?): You need to let your evil motor die on you, then do some diagnosis to find out why. Pull the coil wire and see if there's spark. If yes, leave the key ON and check the "+" terminal on the coil for voltage--it should be 5 to 9 volts. If neither of these are true, then there's the problem. And leave the carb alone! It's not your problem.

Jeff
 
Thanks Jeff, I will try this as soon as I get out to the boat, hope today.
Higgins is from the guy on Magnum PI, liked the show, love Hawaii..
 
Just got home from the boat.
Jeff - I started port engine and checked voltage to coil, it was 3 - 4 amps.
Put wire direct from positive battery to positive coil and got 12 amps..
SO.....????
HELP
 
Higgins: Sammi: Normal. I saw aboutthat on mine as well. When the resistor heats up, the voltage drops. It's okay. Also, it's called good acting! (Hillerman)

Sammi:That's a good one. Note that they included a ballast resistor in hte package? That's to protect the coil if someone leave the ignition ON by accident. Good idea to include it. Use it instead of the Mopar one.

Jeff
 
Jeff
Do you think it would hurt anything if I tried to test run it with the hot wire for an hour or so? I just tried this at the dock for a short time.
Thanks
 
You checked for crossed wires as Jeff suggested, did you actually perform a cylinder power test as suggested?

Don't discount new ignition parts. Have had many a new dist cap, wires etc fail. With engine up to temp (if you can) check for spark at every plug, and make sure it's a good spark.

Once convinced the ignition system is up to spec including timing and that you're getting proper advance, check your fuel delivery system. If you have a metal canister in-line fuel filter just before the carb, replace it as well.

Most manufacturer's help lines will start with a few basic steps that include believe it or not; a) do you have too much oil in the engine? a common cause of a lot of headaches. b) have you done a compression test. c) have you done a vacuum test?
 
..."Do you think it would hurt anything if I tried to test run it with the hot wire for an hour or so?"

You might, but if you run it that way for a minute or so--and it runs better--that says your spark is too weak. I'd try it.

Jeff
 
HIGGINS83 said:
Just got home from the boat.
Jeff - I started port engine and checked voltage to coil, it was 3 - 4 amps.
Put wire direct from positive battery to positive coil and got 12 amps..
SO.....????
HELP
Click to expand...

Just to clairify, you do mean volts not amps, right? Are you getting those voltages from the good engine as well?
 
I took the boat out and ran it until it did its thing. Then wired direct from coil to battery and it purrs at all RPMs .. No Stall, No Kill
Is it possible it could be voltage regulator?
I do feel a little better, like I am getting closer.
Thanks for all the help.
David
 
Back
Top