View Full Version : Hard start when hot with new dist

mag rag
08-18-2003, 10:58 AM
I have been running the following for quite a few years -single point dist. 6al box and blaster 2 coil. This summer I installed a MSD 8361 dist and when the engine was hot it would be very hard to restart not knowing exactly what the problem was I reinstalled the points dist and everything was back to normal (easy hot starts) No ballast resistor has every been installed.
Any suggestions?? Thanks Garry

08-18-2003, 09:27 PM
What is your initial timing set at and which bushing and springs are you running in the MSD Distributor? Also, do you know what the original timing curve was from your points distributor? You may want to check the timing with the points distributor installed while the engine is being started and then do the same with the MSD Distributor. Compare the two numbers to see if they are the same.

MSD Tech1

mag rag
08-19-2003, 05:58 AM
When I mean hard start I mean that the engine will crank o.k. but will not fire. Leaving the hood open for a few minutes and it will fire up. One time I stalled it and it would not fire up until I opened the hood and in five minutes fired. Checked for gas and that was not a prob. Water temp was at 185 so excessive heat was ruled out. I had a similar problem about 6 years ago when I installed an Accel pointless dist Same no start when hot but with that dist it was a 30 to 60 minute cool down before restart. So I decided that this year was time for an up grade with all MSD parts and now I still can't use my new dist.Once again with old dist starting cold or hot is instant
Please help Have a $200 dist on workbench and $50 p.o.s. in car that works. Thanks

mag rag
08-19-2003, 06:03 AM
Sorry I didn't answer your questions. Timing was set as close as possible to the points dist. 18 initial andabout 14 centrifugal also tried vac hooked and also plugged.But the engine never cranked hard just no fire when hot.

08-19-2003, 08:51 AM
Since the engine cranks easy but does not start, make sure that you have a ground from the engine to the chassis. Poor ground could cause hard starting. Although if you are not getting any spark you will have to perform this spark test, but has to be perform when the engine does not fire.

Checking The MSD Ignition For Spark
The following test will determine if your MSD is producing a spark.

Magnetic Pickup Trigger:
If you are using the 2-Pin Magnetic Pickup of the MSD to trigger the ignition, follow these steps.

1. Make sure the ignition switch is in the Off position.

2. Remove the coil wire from the distributor cap and position the terminal so it is approximately 1/2" from a good ground.

3. Disconnect the MSD Magnetic Pickup connector from the distributor.

4. Turn the ignition to the On position. DO NOT CRANK THE ENGINE.

5. With a small jumper wire, short the Green and Violet magnetic pickup wires together then pull the jumper off. Each time the short is removed a spark should jump If spark is present, the ignition is working properly.
If there is no spark:

A. Inspect all of the wiring.

B. Substitute another coil and test again. If there is now spark, the coil is at fault.

C. If there is still no spark, check to make sure there is 12 volts on the small Red wire from the MSD when the key is in the On position. If 12 volts are not present, find another 12 volt source and repeat the test.

D. After inspecting the test procedures and inspecting all of the wiring, there is still no spark, the Ignition is at fault.

If the MSD Unit produces spark when it does not want to start, do the following test on the distributor.

The magnetic pickup in MSD Distributors can also be checked with an Ohm meter to make sure it is within operating specifications. Once again, connect the Ohm meter's leads to the two terminals of the pickup. The resistance should be within 400 - 1,300 ohms. If the resistance is out of this specification, inspect the condition of the wires leading to the pickup for abrasion, shorting or opens. If the wiring is okay, the pickup is at fault.

NOTE: The Ignition will check good if the pickup is at fault.

mag rag
08-20-2003, 07:22 AM
Let me re-enter my problem. First with points dist there is no start problem- hot or cold it would alway fire up immediately. Then install MSD 8361 dist and it fired up cold or warm with not problem but if you drove a distance left the hood down and tried to restart it would crank and crank and crank and crank and then fire. I put up with this for a weekend at a car show 90 miles from home so I found that if I open the hood it would restart sooner .The next week I simplily reinstalled the points dist and have had no hard start problem. So I figure it must be something the the dist is doing. The coil is a blaster 2 purchased in 1992. Could this dist need a balast resister.Could the coil be bad but work fine with points dist.
This is very flurstating as I figured that going to a MSD dist with all other MSD components, with the plug in connecters it would be a simple and improved ignition system. But hence I am very disappointed. Please advise. thanks.

08-20-2003, 10:35 AM
The MSD Distributor or ignition does not require a ballast resistor in the system and that should not have any effect on the starting of your engine. If the coil works with the points distributor then it should work equally as well with the MSD Distributor. The coil has no idea what it is connected to. The one thing that I would look closely at is the resistance of the trigger pickup in the distributor. The magnetic pickup in the MSD Distributor can be checked with an Ohm meter to make sure it is within operating specifications. You need to check that when the pickup is cold and when it is hot. All you have to do is connect the Ohm meter leads to the two terminals of the pickup (one to the Black/Violet wire and one to the Black/Orange wire). The resistance should be within 400 - 1,300 ohms. If the resistance is out of this specification, inspect the condition of the wires leading to the pickup for abrasion, shorting or opens. If the wiring is okay, the pickup is at fault.

MSD Tech1

mag rag
08-21-2003, 07:18 AM
Thanks for your help .I checked the ohms cold (dist on workbench) and the reading was 592 ohms ; then I put a heat gun on the pick up and heated it to 300 degrees then it was 782 ohms. Does this sound like a good test to you.I really hate to put dist in car to do this test ,do think that 300 was enought heat??Is there a better was to heat pick up off car ( running 12 volts thru it??)Was wondering if heat gun did not really heat inside of pick up!?
This dist is brand new and prob. has only 200 miles on it. Also I just remembered another event on the way home the last time I had the dist in. It seemed that at low RPM it would run rough and stall
( at one time I clutched in a turn and it sputterd and died- put in gear before stopped and it restarted by popping clutch) It also died at a traffic light on the way home that day( very hard to restart and only after many minutes of hood open cranking) This was a quite hot day about 90 degrees. Thanks and I hope maybe that this shed more light on the problem and gets us closer to a solution.

08-21-2003, 09:01 AM
The bench test that you preformed on the distributor pickup is fine. 300 degrees is plenty of heat and your distributor is probally not seeing more than that. As for the shutting off of the ignition while you where driving, that is usually an indication that you have a loose connection or a wire that is only making contact with a minimal amount of wire strands. Sometimes this is caused by over stripping the wire insulation and or by a bad crimp. A test that you can perform to see if that is the case is to attach a handheld volt meter to the small gauge red wire of the msd and then drive the vehicle with the meter on so that it indicates that 12 volts is present. When the vehicle acts up look over and see if the 12 volts is still present.

MSD Tech1