I've got a question for you?

[Double Venom]

Cobra-351 - everything is as expected-Carb'd.

PROBLEM: Engine will not start in cranking mode.
Solutions; New Solenoid- (has power with the key)
New Ignition switch- all contacts checked and working.
Push or Pull the car, pop it in gear and it Fires right up! ?
Yes, has an MSD 6, with matching Distributor- ALL checks-OK.

Engine STILL cranks over- but will not start, back to the push pull mode and it will fire right up.

What am I missing?

?

DV

[Tommy]

To my simple mind, you are getting power to the ignition circuit when the key is in the run position, but not when it is in the start position. Sounds like a bad ignition switch to me. I'd put a voltmeter on the wire carrying power from the ignition switch to the MSD system and verify that it's getting power with the key in both the run and start positions. If it is, then you've exhausted my limited knowledge.

[Ron61]

Tommy,

If the engine cranks over ok, he must have power in the start mode of the ignition switch.

Can you bypass the MSD unit completely and try it with just a regular ignition wiring set up? I have mine wired to a terminal strip so I can take two short wires and disconnect the MSD unit and then just use the coil and distributor like a regular unit and it has worked when I tested it. Also if you have another person there, try having them watch the high output wire of the coil and see if you are getting anything out of it when you crank the motor over or use a remote started and do it yourself. Note! You can get a real jolt if it is putting out the correct voltage, so be careful, but I am sure that you already know that.

Ron

[rustyBob]

ign.switch........

[bermblaster41]

I agree with Tommy. Sounds like you have a problem in your start circuit. I would use a test light out to your msd and check there. Good luck Berm

[ERA713]

This happened to me once.Check your switch I had power to ign in run position but no power to ign in start position.good luck.

[Double Venom]

My fault by not describing this well enough.
The ignition switch was replaced. Told the owner the same when he described the problem. A new Ford switch was put in place,still wouldn't fire unless pushed- Not even fast either!.

I have talked to MSD and we even went way farther than there standardized testing....The MSD IS firing right, OR it wouldn't start at all!

Earl I may do that just to bypass it all!

As of now same problem, cranks wont start-pushing will fire it immediately?

??

This AINT a test fellas this is a real problem that is kicking my butt!

DV

[Tommy]

I would run a jumper from the hot wire going to the ignition switch to the wire to the ignition system. That will guarantee you have power to the ignition system. Hit the starter and see if it starts and runs. If it does, then either the switch is wired wrong or the switch is not working correctly.

[snakebitekit]

what did you do with the white wire from the MSD box? If it is connected to the starter side of the switch you would be grounding it out during cranking but not when the key is just in the on position, which is why it would start by pushing. Maybe?

[Hray]

A short story for you, and maybe a solution. I bought this 55 chev a few ago, had a elect ingnition from newer car. i would crank and crank the car and it would not start, but i did notice that when I let off the start mode the motor would seem to catch. so I determined on the chevy ignition switch when the key is turned to the start mode that the contact going to the ignition switch is lost and that the extra wire that would bypass the resister is supposed to then carry more voltage to the distributor. When checking the thing with the key on I got plent of voltage to the distributor, but I lost all voltage when turned the key on over to the start mode.

This sounds like a similar problem, on the chevy there was enough momentum to get it to fire when you returned the key to run position. I am going to guess your motor is too tight and that the instant you let off the key from start the motor basically stops.

This is my only guess.

Good luck and waiting for the real answer. Ray

[BOBM]

Still waiting for the real answer. Bob

[Double Venom]

Bob,
I like your response..........
Still waiting.......Me too!
Got a hold of the guy with the problem, said he checked every wire, every connection and has since put a third ignition switch in.....
cranks-no start, ignition on, give the slightest push and varooom!

I told him to trailer it, push it, what ever and get it here. I will post the results. In 30 years of building custom cars, it's the problems that are NOT a problem that are the hardest to fix! Think about it.........
DV

[BOBM]

Just a thought, If the car is cranked with the key, when in gear with the clutch depressed, does this make any diff??

[Double Venom]

Bob,
Good question, see where your coming from. ALL Neutral Safety switch(s) have/has been taken out of the equation!

Owner finally in the shop yesterday, came walking in with rheims of papers, notes etc. Still has the same problem!

During conversation a wee bit of evidence may have creeped in ?????
Under the dash (This car has been on the road successfully for over four years!) looking for any indication-s as to why! He tells me the large purple (Neutral safety wire on this type harness!) wire appeared to have gotten hot and partially melted the wire next to it. AaAHAHA, Now I / we have a clue, wont know until he gets the car here. Any one else care to give an educated guess/ answer?
DV

[Tommy]

I'm thinking your responses might have been different if the initial post had said:

Engine that ran normally for four years now won't run when cranked by starter. It has two melted wires running to the ignition switch and will run when push started.

[sunman]

DV

I was electronic tech for years. Maybe this will help. Use voltmeter to check voltage while cranking at ignition box. If good check output to dist. If bad work backwards to cranking power source. In electronics its just like everything else, divide and conquer. My guess is bad wire in cranking power circuit.

Thank god you have a simple problem and your not replacing Q panels and floors on classic Mustangs.

Sunman

[Ralphy]

Hray,
Once owned a Buick and if you released the key fast, the motor would catch. Came to find out GM ran a dual voltage ignition system. When in the start position the coil got 12 volts. Once running the coil had 9 volts running to it. The car was a beater, so I made a jumper wire that I ran from the battery to the coil. I would use it for starting then remove.

[Hray]

Ralphy: that is why we are all gearheads, if you can't really fix it just figure a way around it and just keep truck'n.

Ray

[Double Venom]

Ralphy,
Wasn't a 50's (& up) GM car that used a ballast resistor at/to the coil but a 72 VW Bus! VW couldn't find it and neither did I! Like Ray says, OEM? To Hell with OEM, I want it to work!
I did what you described only instead of having to get out of the Van, go to the engine compartment hook, unhook the extra wiring, I simply 'hard-wired' the extra hot wire in place and put a toggle switch on the dash to either break or make the circuit! That problem was fixed, maybe not repaired, but it WAS fixed!

Sunman, I love soldering in floor pans, and 1/4 panels in vintage Mustangs-I really do! (You should see some of the floor/trunk pans I have made by hand with all build in valleys, pockets., ridges, and these were for a Kennedy Lincoln, '57 Chevy's, '56 Chevy's and on and on! Now you can buy complete pans already with the factory stampings in place!

DV

Sunman, I will do exactly as you say once the guy gets his/the car here!

[Camaro Man]

I have to admit I didn't read every post, but I have had a lot of problems burning up the switch under the dash on the column and replaced it several times before I finially put a relay on my electric fan. The problem seems to be resolved.