No Spark - Need a fresh brain!!!!

[Poundz9oh9]

SBC 350/HEI, Composite cam gear, No Spark out of the cap. Has electricity going in during cranking with the key. I've changed all the internal parts of the distributer. Coil, condenser, module, pick up coil, to include changing the cap and rotor. So I basically have a new distributer. I seem to have checked everything that I can think of and I'm still not getting anything to the plugs. Anybody have an idea???? This is the only thing keeping me from getting my first start. HELP!!!!!!!!

[grumpyvette]

things to check

 

many engines have a LOW oil pressure cut off switch that cuts power to the coil if the oil pressures not 7 psi minimum

 

your ignition switch may be defective?

 

the wire from the starter that ffeds the coil may be incorrectly hooked up?

 

your coil may be bad or not correctly wired?

 

do you have 12 volts AT THE COIL?

 

 

 

links that may help

 

http://www.classictruckshop.com/clubs/earlyburbs/projects/trouble/ignition.htm

 

 

 

http://auto.howstuffworks.com/engine11.htm

http://www.lotuselancentral.com/timing.htm

 

http://www.centuryperformance.com/timing.asp

 

http://www.amxfiles.com/resource/tech/timing.html

 

http://www.centuryperformance.com/vacuum.asp

 

http://msdignition.com/1troubleshoot.htm

 

http://www.barrygrant.com/demon/default.aspx?page=28

 

 

 

http://www.centuryperformance.com/point_settings.asp

 

http://www.centuryperformance.com/point_settings.asp#TROUBLESHOOTING

 

http://chevyhiperformance.com/howto/97438/index1.html

 

http://abbysenior.com/mechanics/ignition.htm

 

http://hometown.aol.com/dvandrews/timing.htm

 

http://www.driveline-uk.com/FAQ/Faq_Timing.htm

 

http://www.centuryperformance.com/point_settings.asp

 

http://www.boyleworks.com/ta400/psp/distcurve.html

 

http://www.oldengine.org/unfaq/hei.htm

 

http://mantaproject.com/hei7wire.html?POSTNUKESID=fd5fdfebe88245bcf80c3425a6a7d52d

 

http://www.classictruckshop.com/clubs/earlyburbs/projects/trouble/ignition.htm

 

http://www.type2.com/~bartnik/timing.htm

[dmyntti]

This may sound silly but check to see if you havea good ground. It is possible that your distributor is not grounding to the the engine or the engine is not grounded to the frame. I have seen both of these problems. Also if this is a HEI make sure the wires off the pickup are not shorted to the distributor body, they can get pinched or rub through at the bottom of the distributor body. I had that one on a Camaro once that drove me nuts for an entire weekend until my boss bet me he could fix it. It took hom five minuted to find the problem. Unfortunately you have to dissasemble the entire distributor to fix this. This is apparently a common problem with HEI's.

[Guest tony78_280z]

I agree with grumpvette.

 

I had the opposite situation. I had Dizzy juice to only when the key was in the run position, not in the start position. I had to crank it and get the motor to spin real good, then let up off the key and it would start. On my ignition switch there was a mysetrious extra pin that was not hooked up to anything in the stock wiring. It has power in the start position. So this then took the juice to the dizzy and solved my problem. Spend some time with a wiring diagram, a test light, and your ignition switch.

 

I supose a quick test would be to strait wire your dizzy positive to the battery. (of course put a fuse or fusable link in there just in case) and see what happens.

 

If I'm not mistaken,.. HEI type Dizzy does not have a ground wire. The ground wire is actualy your tach. It grounds into the engine... so you might check your motor ground.

[LS1 Z]

There is a ground strap for the coil. WELLS part number GS1. One end atatches to one of the coil hold down bolts and wraps around, I believe to the center terminal.(male) Hope this helps. Don't see alot of HEI'S anymore but..... from what I can remember a missing ground strap can either take out the coil or module. Hope this helps

JOEY

[Poundz9oh9]

ok guys, update ................

 

I have ran the hot wire straight from the battery ......... Nothing

 

I tapped into the ground and added another good positive ground straight to the ground wire that comes from the dizzy to the coil plug in ........ Nothing

 

I got a new coil ...... Nothing

 

Got a complete rebuilt distributer ....... Nothing

 

Man, I'm sooooo close and this thing is killing me. Now, the new coil I bought has that ground wire that attaches under one of the coil screws. Is it a possibility that the wire is not enough and I need to run the actual all metal ground strap that you buy seperately? I assumed that the wire was all that was needed.

 

I've never seen anything act like this and I've cruunched brains with a few other local guys. I don't know their experience levels but I know that you guys usually have the right answer. This is really getting me so frustrated that I want to quit because I'm at my wits end................

[awd92gsx]

Stupid question time:

 

Are you sure the distributor is actually turning?

[Guest tony78_280z]

Ok.. to make a long story short, (and far less embarassing) I once forgot to put in the rotor when I upgraded my dizzy. It spun when I hit the starter, but got no spark. Had me stumped for some time (longer than I will admit) before I saw the rotor sitting on the cowl. So I'm gonna suggest you go over everything you did, again. Step by step and see if you forgot something simple. (like leaving out rotor, or not plugging in the wiring harness from the module to the coil, plug wires hanging loose etc.)

 

This rebuilt dizzy.. did you rebuild it? or did you purchase a rebuilt piece? Is it spinning and in all other aspects working properly?

 

Bad module = no spark too. And I hear you don't get the electric greasy stuff smeared on there real good, and the module good and tight then they fry out in no time at all.

[jt1]

Have you checked to see if the distributor is in phase? IE, when the pickup triggers the spark, the rotor button is close to the terminal in the cap?

 

John

[grumpyvette]

its begining to sound like a toasted ignition module

[awd92gsx]

I think that's one of the things he's replaced a couple of times.

[dmyntti]

I do not believe there is a direct ground from the coil. The distributor grounds through its body. The spark is initiated by the distributor switching the ground on and off. The wire on the distributor is the tach terminal as someone mentioned before. If this is grounded the plugs won't fire. When I mentioned the ground in my earlier post it was meant to be make sure the distributor body is grounded. You should be able to put a test light on the tach terminal and see if it is switching when the engine turns over. You can also take you module to an autoparts store and have it tested, it is a common HEI problem.

[jt1]

Is the engine itself grounded back to the chassis and battery?

[Poundz9oh9]

ok, here we go.

 

I checked the wires at the coil. Used the ground wire as the ground. Both of the other wires are hot with the key in the on position.

 

I completely unplugged the tach. It's an autometer Phantom series.

It has the three wire plug in, in the back. A ground, a 12v, and the signal input.

 

I checked on the test light, grounded to the ground plug for the tach and checked both the 12v and the signal wires.

Both are constantly hot when the key is in the on position and during cranking.

 

The motor has a good ground in three places. Once to the battery and two to the firewall.

 

The rotor is in and makes good contact. It does spin. The rebuilt distributer is an autozone oem replacement.

 

hmmmmmmmmm. And I think that's it so far this morning. Going back out to the car to poke and prod a little more -- be back soon unless it starts. So I'll be right back I guess

[dmyntti]

If the test light isn't turning on and off when the engine turns over then you are not switching the coil on and off, so you won't get a spark. This usually would be a pickup coil or a module but you have changed both of these so I am not sure. You could try attaching the test light from the distributor body to a good ground with the key on. If it lights then the distributor body is not seeing ground. I doubt this is your problem but it is an easy check. I saw this happen once on a car with a painted intake manifold and the paper distributor gasket installed. My van actually has a ground wire attached to the distributor hold down bolt.

[jt1]

Excessive reluctor/pickup clearance?

[Poundz9oh9]

went out and bought an ohm meter / volt meter and everything has checked out ok --- except this test light turning on and off thing .....

 

So, correct me if I'm worng -- but the tach input signal should be blinking on and off at the test light during cranking?

[dmyntti]

That is right, the tach signal should switch from +12 to ground while cranking. Power goes into the power connection of the distributor through the coil and then is intermittantly attached to ground by the module when the distributor turns. When the module grounds the distributor, current goes through the coil and charges it. When the ground is removed the coil fires the spark plug. You will see +12 on the tach terminal when the module is not connecting to ground (no current flowing through the coil) and see ground at the tach terminal when the module grounds the coil (current flows through coil). I hope this makes sense. It appears your distributor is not switching to ground and therefore not charging the coil.

[Poundz9oh9]

so -- that would be a module problem .. no?

[dmyntti]

Likely, but it could be a problem with the pickup or the wiring as well. If the pickup does not work then the module won't get the signal to switch the coil. If the wiring is cut or shorted inside that could cause the porblem, if the distributor body does not have a ground then there would be no ground for the module to switch to.

 

The most likely cause is the module however. I know you changed it once but maybe get it tested to see if it is the problem. The autoparts stores around me will test them free of charge.