motor dies after it gets to temp

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72duster72

72duster72

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I have a 72 duster408 stroker. I have a msd6al box, new msd blaster 2 coil, I will be replacing the electronic distributor with a new one I have. So sympton when the motor gets to 192 the engine dies. 1st I thought it was vapor locking because of temp but I changed the fuel system from carb to fuel injection. The entire fuel system changed. It still fails with carb or fuel injection. The fuel injection does have a hand held unit so I watch and at 192 I loose spark not sure why. I hope I made it clear as I can.
 
Define dies? Stutters and dies? Stumbles and dies? Drops rpm slowly and dies? Completely just shuts off like you turned the key? Losing spark at higher temp tells me heat is effecting something. Have any unshielded wires somewhere?
 
Very very very very first thing to do is try to determine if it's fuel or electrical / ignition.
 
I do have electric fans.I do have 100 amp alternator.i would not think it would be fuel since it did it with carb and fuel injection.when I installed fuel injection everything was changed tank,lines etc.and on gap I will check.
 
Have you looked into the carb throat to see if it sprays fuel when you push the linkage back?
 
Yeah, my money is on the dizzy pick up coil failing.

Happened to me...car would die when warm. Wasn't so much that it was warm, such that it'd be running fifteen minutes and the pick up coil would fail open circuit due to temperature. Therefore, no spark.

This happened with a brand new zero miles MP electronic distributor. The next time the car dies, disconnect the distributor fly lead, and measure across the two contacts. Anything more than a thousand ohms, it's toast.
 
Ok so is this happening when the fans come on or try to? Voltage drop in the system... Bulkhead connector.....
 
Get a voltmeter/ohmeter if you do not have one. (It will be very useful on others things.)

Make sure your wiring is correct to the MSD:
An Error Has Occurred!

Using the ohmeter mode of the meter, disconnect the pick up leads and measure resistance into the 2 pickup leads. Actually, anything over 500 ohms is suspect. Then when it fails, do that same and see if the resistance has gone up. This will test your reluctor..... Or, just swap in the new distributor.

With the meter as a voltmeter, check that there is 12 volts to the small read wire on the MSD. Monitor this voltage when the car is running and see if it becomes erratic or drops to zero when the problem crops up.

Do the same for the big red lead to the MSD.

Make sure you have a geound lead from the battery to the lower front of the engine block, and also another from the back of the passenger side head to the firewall.

Is the MSD unit near to the hot exhaust? Is the coil mounted on the engine block? Either getting too hot could cause this.
 
Reluctor ohm reading old distributor is 417 the new is 350 the gap I believe thickness 19 or business card thick. That all I have been able to do.
 
Good numbers on the reluctor.

If the gap is .019" then that is waaaaay too wide. I should be .008" You can use 3 thicknesses of light copier paper to approximate .009-010". But be sure on the biz card stock thickness; you don't want to chase your tail on this. The right thing to use is brass shim stock from the hardware store. You're not supposed to use steel feeler gauges.
 
72duster72 said:
Reluctor ohm reading old distributor is 417 the new is 350 the gap I believe thickness 19 or business card thick. That all I have been able to do.
Click to expand...

Just to be certain....are these ohm readings taken IMMEDIATELY AFTER the engine has cut out, because those measurements are irrelevant in the search for your problem if they're cold measurements?
 
^^^Yeah, as I said in post #9....you need to take the meter reading when the engine has just cut out and died. When it happened to me, my pick-up coil read open circuit. Twenty minutes later it read 450 ohms.
 
Take someone with you for a ride. As soon as it dies, jump out, pull a plug wire, stick your finger in the end and let your friend spin the engine.
 
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