Please Help!!!

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hurleyguy

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I have a 68 Dart post car that suddenly stoped starting if i let it sit for a few days it will start but only run for 30 seconds if i am lucky during that 30 sec it runs great revs awesome it is a new 360 with maybe 3500 miles a nice voodoo cam big valve heads ported and polished all new starter starter solinoid ignition ecu distributer and ignition switch any ideas would be great i have also redone all connections and grounds in the engine bay havent gone under the dash Thanks For Any Help
 
Sure whenever i try and start the car it will not start it cranks very strong i have power to the coil and sometimes i have spark from the coil and that is when it starts but it only runs for 30 seconds and then shuts off no matter what i do it wont restart i recently pulled a plug to check for spark and it has a very weak spark sometimes if any at all
 
i recently had the same issue, it would start and then shut off , then it would refire and run all day. it gradually got worse to the point where it wouldnt start. i thought it was a fuel problem, nope, gettin gas. i switched out the ballast , no change. i switched out the ECU no change. WTF, so i took out the second ECU , took a flap wheel to the mounting tabs on the box and the fender apron where it mounts. fired right up and ran all day no problems, and is still running great to this day. just for kicks i put the old box in and no fire. something to check
 
Everything is good in the distributer and I also did replace the ecu and also ran a separate ground to it from the frame I just put the old box back in and it started up ran for 30 seconds and shut off now won't start again put back in new box and won't start so put back in old box and still won't start
 
Check the plastic connections at base of steering column.Have had this problem on several a bodies.
 
How do you know at this point whether it's fuel or ignition?

For testing, go down to Radio Shack and get an NE-2 neon lamp. "Rig" the lamp up where you can see it, such as a slot on the cowl and some tape, etc, ground one lead. Run the other lead with some wire down and wrap 4-5 turns around the outside of the insulation of the coil wire. This should make the neon blink when the engine runs. It will quickly show you if the ignition is dying or not

Make a couple of tests. Put the key in "run" engine off. Check the "switch" side of the ballast, or if you don't know, try both sides. and pick the side with more voltage. Leave that meter probe on that ballast resistor terminal, and move the ground probe over to the battery POSITIVE post. You are hoping for a very LOW reading, the lower the better. More than .2--.3v (3 TENTHS of a volt) means you need to look at the harness and find the voltage drop.

Also "wiggle" the key in the switch and see if the voltage "goes away."

Next time the engine dies, do NOT crank it again. Pull the air filter, use a flashlight if necessary, and pump the throttle while looking down the carb throat, and see if you are getting fuel out of the accelerator pump.
 
I will try that I know I am getting fuel i have kept the air filter off to make sure it's getting fuel I am running a brand new Holley blue pump Holley regulator and 750 double pumper when it does start it runs great fires right up and revs good just not for long
 
is it cranking ~ no fire

no crank ?

did you bypass the Neutral Safety Switch ?

will it start at the starter relay?

do you have spark at the coil ?

plenty of fuel?
 
hurleyguy said:
Cranks no fire stong crank have plenty of fuel and small spark from the coil
Click to expand...

From those of us trying to help you, this is not very descriptive.

Did you test the spark USING THE KEY to crank the engine, or by jumpering the relay?

Did you make the voltage tests I suggested?

One thing you can try, is to make up a big long clip lead out of at least no 14 wire, long enough to go from the coil + terminal to either the

starter relay battery stud .....or....

the alternator output stud.

This will effectively "hot wire" the car and guarantee good power to the ignition.

THEN try cranking the engine and checking the spark.

If you still get a weak spark, it's

probably the coil

Might be the ECU. CHECK and scrape clean the ground/ mounting bolts for the ECU
 
Yes i did those test with the neon and it worked fine i also replaced the ecu and cleaned the fender it is mounted to also ran a ground wire to it still no start, One thing i did this weekend was put a dual point distributer in the car started but would not run well when it shut off it starts a fire in the carb so i need to try and time it better i suppose. So now it starts but wont run worth beans.
 
I would leave the dual point in there until you get this sorted, as long as you think the dual point is OK.

Make sure the points are correctly set

Make up a long clip lead so you can "hot wire" direct from the coil + to a battery source.

Crank the engine (jumper the relay if more convenient), and check spark right at the coil tower, by using a grounded probe. You should get a NICE hot blue spark, at least 3/8" long, sometimes as much as 1/2" long.

Wiggle the rotor in the dist, it should spring back, showing the mechanical advance is working.

What you describe now suggests retarded timing. Do you know where the timing is set?
 
Alright i finally got everything running great with the dual point starts everytime and runs good just for fun i put in all the new electronic ignition parts ecu distributer and it would not start so i guess dual point it sis how high can a dual point rev it is a mallory i need it to atleast rev to 6000
 
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