I really hate to ask a gm question hear but I cant seem to find any ideas. I have a GM industrial 292 straight 6 it is in a john deer combine and, we still have corn out so I am starting to get desperate. The issue seems to be in the ignition it has a points distributor new delco points/condenser/copper contact cap/rotor/coil/spark plugs and new plug wires. It also has 12+ volts at the coil. For some unknown I just cant get a good spark to the plugs there is a weak yellow spark at every plug and it wont run at all it just fires while cranking I am for a loss.
once agin sorry for the gm question

_________________
85 d-100 HEI 2BBl
06 Toyota Corrola

I'd be checking the coil. Swap out another you know is good. Also, check to make sure the points have a good ground inside the dizzy, no grease under them etc. Keep us informed.
best regards MaX

Did GM coils not have an external ballast? I can't remember if either of mine did.

12v to a points coil seems too high.

~RDE~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

GM's use a resistance wire to run coil off start position. Starter solenoid has 2 small wires and the power feed big wire, maybe they are on wrong terminals.

Richard

_________________
Part of Tyrde-Browne Racing

The wiring diagram shows a red 10 ga wire from the solenoid to a relay and a white wire from the ignition to turn on the relay and a black wire that runs from the relay to the coil. It does not show any resistor or resistor wire it the ignition circuit. The coil is from john deer for this application, it has delco markings on it. I am certain that it is wired the way the diagram shows.
Thanks for the ideas

_________________
85 d-100 HEI 2BBl
06 Toyota Corrola

It sounds like you have SOME spark while cranking.

I'd pull the coil wire from the dist cap, remove the dist cap, turn the crank to position the points to closed, turn the key to run, and finally open the points with a popsicle stick while checking for quality of spark leaping from the coil wire across a 1/4 inch gap to ground. If it's not decent there's a problem upstream.

Does the solenoid have an extra wire to feed the coil direct when cranking? I had a Corvair with a problem kind of the opposite of yours. It would crank without starting, but if I released the key at the right moment it would start and run. It was something along the lines of a bad or disconnected bypass wire from the solenoid to the points. http://i62.photobucket.com/albums/h89/j ... rampg1.jpg

Hi Dan, and welcome to the forum, nice to have you with us. Good practical advise is always welcome.
In the diagram you link to, there are two wires that connect to the plus side of the coil, one comes from the starter relay, and may be there to ensure a full 12V for starting, or maybe as a bypass wire? The other wire disappears somewhere out of the picture, and the question is if that wire is connected to a ballast resistor, or just to the ignition switch?

Olaf.

_________________
Aspenized

Carl
Sounds like a BAD GROUND. Check your set-up any where you have a ground from the battery through the intire ignition system take it off clean it and sand any metal.
This has been a problem for me on my equipment when I farmed in Ohio.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Ok, I checked my ignition system over and I can get a half inch blueish white spark from the HV coil wire by takeing it out of the distributor and holding it away from the block and cranking it. I can get a eighth inch spark from one of the spark plug wires using a screw in place of a spark plug while cranking, now hear is where I get tripped up if I put a plug in place of the screw and ground it to the block then all I can get is a very weak yellow spark hummm? I wonder if my new plugs are bad or incorrect they are AC Delco R43T's wich are a resistor plug...... too much resistance for the ignition system mabe?
I don't know

_________________
85 d-100 HEI 2BBl
06 Toyota Corrola

Why in the world would there be a need for a resistor plug? If you have awesome spark at the plug wires, and lame spark with the plug in, logic tells me its the plugs.

Do you have a spare regular plug laying around? Swap in a standard plug and see what happens. I would bet that solves your issue.

~RDE~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Switch to NGKs Ac Delcos are now made in China and have been know to be bad out of the box.
Frank

_________________
Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered