[Old Man Taylor]

Well, I attempted to race in the Pontiac Drag Days race at Palmdale today. It is hard to believe in California, but I drove through snow and rain to get there. The weather was bad enough that the track did not open for the drag races. I completed the 150-mile tow back home, tried to get the car off the trailer and it wouldn’t start. No spark! If I recall correctly I have posted of two or three MSD failures already. I don’t know what this is yet, but no spark sounds a lot like another MSD problem. The car must be parked outside for now, and the weather precludes me working on it. Since I go in for minor surgery Tuesday, I may not have the car ready for the March 24 race. Needless to say I am very disappointed.

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Jim

[Old Man Taylor]

Well, I attempted to race in the Pontiac Drag Days race at Palmdale today. It is hard to believe in California, but I drove through snow and rain to get there. The weather was bad enough that the track did not open for the drag races. I completed the 150-mile tow back home, tried to get the car off the trailer and it wouldn’t start. No spark! If I recall correctly I have posted of two or three MSD failures already. I don’t know what this is yet, but no spark sounds a lot like another MSD problem. The car must be parked outside for now, and the weather precludes me working on it. Since I go in for minor surgery Tuesday, I may not have the car ready for the March 24 race. Needless to say I am very disappointed.

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Jim

[David Holmberg]

Man, Sorry to hear about the bad day... I hope the "No Spark" is just a loose wire.
Best of luck this week.

[Doug]

OMT, Brave effort on trying to make the session. People seem to not consider the efforts guys like you make to be part of an event. Better luck next time and good luck for the medical stuff too. ( Seems to me that MSD owes you a rescue mission!)

[Hot Rod]

OMT,
How do you have the MSD Box installed, I have been running the MSD 7-AL2 box for eleven years with a hick-up. I know for a fact that they need to be grounded big time!
Do you have it running through the ign-switch, or do you have it running from a seprate switch on the dash!
The way it is installed on my TA is 12 volts direct from the battery (fused) then for the ignition part 12 volts from the battery fused to 30-amp rocker switch to Ign side of the box!
The reason why I did it this way is I had the same problem when I ran it through the stock switch. I installed three switchs and had the same problem! After I set it up the way it is now, not one problem.

I'm quite sure that you have a volt meter, check to see if you are getting 12 volts to the box, and then check to see if you are getting 12 volts to the ignition, then check to see if you are getting voltage to the dist and is the dist grounded properly if it isn't that can cause you to toast the Box. Darn high tech electrical gadgets!!!!!!

This is probably a stupid question because the car has started before, but if you are running the ignition through the factory switch and never changed the wiring to by pass the resister you would only have 6 volts going to the ignition. Just a thought and I have seen it happen before.
The big key to any of the box's is the voltage 12 volts, 12 volts, 12 volts.
And one last thing on the dist are you running a GM HEI or the MSD Billet, because I have seen on the GM HEI's where the voltage was so high that it would cook the rotor button then fry the pole piece and do it in a very short amount of time!
Hope this might give you a couple of ideas!!!!!

Hot Rod

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Outlaw Pontiac Racers Association
"For Those Who Live the Legend"

[r hammons]

on the msd box i had some problems with one i am running , as per hot rods comment they have to have a very good ground i talked to msd , they told me to run the neg (ground wire) to the battery neg post , not the chassis, roll bars or eng block for the ground , my problem was plugs fouling out , since i corrected the groung , no problems

[Scott Misus]

MSD = Multiple Starting Difficulties

[RH152]

put the msd box under your tires and run it over . i race an 11 sec and 9 sec pontiac both cars run points. i won norwalk q16 with no elec. ignition. ive used msd in the past when they work there good . i still will keep my points ignition
Richie Hoffman

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pure pontiacpowerd 86 grand am

[Old Man Taylor]

Hot Rod – I appreciate the thought and time you have placed on my problem. Let me address your issues/questions in order. Ground – I have a 000 ground wire from the front of the frame. It attaches to a bracket that was welded to the frame. That cable goes to a stud on the outside of the firewall. The inside of that stud is the ground source for everything under the dash. Switch – No resistors anywhere. All of the factory wiring was eliminated. I have an ARC switch box for all the electronic control. The ignition output goes directly to the MSD. When I have measured the output voltage, it has been fine as is the ignition input at the MSD box. As a side note, I assured I never loaded the relays in the ARC box to even 50% of their ratings, as the advertised rating does not represent its capability to support continuous loads. Power - The MSD positive power is similar to ground. The battery output goes to the power cutoff switch mounted on the tail panel. The output of the switch has two #8 fine strand power wires. One for the delay box and a separate one for all power consumed under the dash. The delay box output goes directly to the delay box. The other goes to a stud on the firewall. All other front voltage is sourced from this stud. Distributor – This is hard to check. It is an MSD billet distributor. The only wires it has are the two for the magnetic pickup coil. My first pickup coil definitely had a problem. That was repaired, but it was kind of a band aid arrangement. I later replaced it again with the complete MSD replacement part. Both before and after it checked out OK on a distributor machine. I know it is hard to second-guess someone else’s problems without knowing exactly how everything was done. I also know that it is easy for me to get tunnel vision and overlook something. I really appreciate the input. One thing I might do is rig up a direct power wire to the ignition to eliminate any potential problem with the ARC relay inside the switch box. My next course of action is to do the debug procedure that MSD recommends to see what the results are, but I won’t be able to do it for a few weeks.

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Jim

[Old Man Taylor]

RH152 - How do you implement your various rev limiters on your cars, and what is the highest RPM you take them to? I have never had anything but points on my 64 GTO, so I am certainly not against them. However, If I were to eliminate the setup I have on the racecar, I would probably try to get a well setup HEI on it rather than using points. I guess I could tie the three step into a separate soft touch rev limiter for the RPM controls.

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Jim

[Hot Rod]

That is why I have never sent it back in eleven years for updating, it's the fear of loss!!!!!! I have quite a few friends that run the 7AL-2's with out any problems!
I see the MSD guys at the SEMI convention in Vegas and every year they tell me to send it back to get it updated for N/C, well you know the old saying," You don't get anything for nothing", and I feel that if it isn't broke don't screw with it!!!!!

OMT when you figure this problem out please let the world know!!!

Thanks

Hot Rod

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Outlaw Pontiac Racers Association
"For Those Who Live the Legend"

[Dennis B]

OMT Sorry to hear the race was canceled, and that you had to make the long trip home for nothing. I had thought about going down but figured the weather might give me a wasted not to mention long trip. Maybe the next one. Sorry you won't be able to make it to Bakersfield for the March meet. Good luck with the surgery this week.

[KS circutguy]

Jim,are you using the recomended capacitor on the + side of the MSD as per instructions by MSD installation manual?
These are available threw any speed shop,and threw jegs,or summit.
Have done many installs and only had problems when the cap. was left out..I'll see if I can't dig up my install man. and get you a part ##.
Also the box must be grounded to the battery and so should the positive side.....

KS out, [img]/infopop/emoticons/icon_biggrin.gif[/img]

[Old Man Taylor]

KS - Yes, I have an input filter. I don't remember the part number, but it is blue, about 3" high and about 2.5" across. The ground is to the front of the frame and the battery is grounded to the frame in the back.

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Jim

[Old Man Taylor]

KS - The part number of the MSD capacitor I used is 8830. The power for the box comes directly from the power switch at the back of the car.

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Jim

[george kujanski]

One thing to look for that bit me at a previous job designing engine controls.... Is there a possibility in your wiring setup that could somehow allow you to disconnect the alternator output from the battery, thru a switch, etc. while the engine is still turning? If so, this causes an effect called Load Dump which creates a high voltage (60-100 volts) on the alternator side of the wiring. Since most automotive devices are NOT rated for the battery side connections to go this high, this usually destroys the power input circuits. (How do I know, you ask). An analysis of the power input in your MSD box would give a knowlegable technician the evidence of this.

Regards, George

[Old Man Taylor]

George – The way I have it wired I don’t believe that can happen, but I could blow up my alternator. I ran the alternator output to the input of the switch at the rear of the car. This is also the connection to the battery. The output of the switch goes to all the electronics. That is the only way I could guarantee the engine would shut off when the switch was turned off. The switch is the NHRA emergency shut off requirement. I haven’t reviewed it enough yet to see how to connect it so the load dump doesn’t damage the alternator.

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Jim

[george kujanski]

Jim, if your switch disconnects the alternator output from the battery, a load dump WILL happen, and it will affect all devices still connected to the alternator side of the switch. The greater the output current at the time of disconnect, the greater the load dump. Perhaps you can shut down the alternator during the race.

P.S. If the alternator output does not disconnect from the battery, this, the major source of load dump, should not happen.

Regards, George

[This message has been edited by george kujanski (edited 02-26-2001).]

[Old Man Taylor]

George - The alternator does not disconnect from the battery, but it does disconnect from all other loads. The loads are on the output of the power switch, the alternator and the battery are tied together on the input side of the switch. I don’t see how this could cause a problem on the loads, but I am not sure about the alternator. What do you think about both of my conclusions?

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Jim

[george kujanski]

So far your wiring actually sounds ok. If you have gone thru 3 MSD boxes, I would think your failures are application related rather than a MSD design issue. Perhaps we should take the discussion off the BBS. Email at home is electricman@mediaone.net, if you care to discuss it further.

Regards, George