need help. starting problem

[warrpath4x4]

So I have a 72 blazer with a 350 from a 76 with the HEI ignition. It will start when you hold the key in the start position but when you let go it dies (bought it this way). I checked the ignition wire going into the distributor and have power in the on position, start position, and when you release the key. It has a new Accel distributor and a new coil.


Any ideas will be great.

 

[diesel4me]

You may think its getting 12V on the "run" position,but I bet someone used the original point ignition coil wire to power the HEI coil--that wire is a resistance wire and will deliver only 9 volts or so at reduced amperage ,which kept the points in the original distributor form burning up rapidly..there was a yellow wire from the starter solenoid that gave 12V while cranking to the original points coil to ease starting,that only got energized while the starter was cranking..

An HEI needs full 12V to work right...so you'll need to run a new wire from the fuse box from a source that is only hot when the key is both in the "run" and "crank" position..but not when its on "accessory",so the HEI wont get power when your parked listening to the radio,etc..you can determine that with a test lamp..

A quick test to see if thats your problem is to hook the HEI "Bat + " terminal directly to the battery positive terminal and see if it will start up and stay running..if it does,you need to run another wire to it as described..

 

[warrpath4x4]

Thanks for the info, I was just thinking about that tonight running a jump wire from the battery.

 

[79HeavyChevy]

Do it from something that is swith hot when you turn the key to on, if not it will keep running untill you pull that wire from the battery or it runs outta gas.

 

[ryoken]

usually the resistor wire is cloth covered, as opposed to plastic-jacketed too...

 

[diesel4me]

That's true on many older GM's from the 60's,it had that asbestos cotton covering for insulation..but they started using wire that has a special conductor with "normal" looking insulation on the 70's vehicles with points..I didn't know you could buy this wire from Standard/Blue Streak at parts stores until recently!..

 

[warrpath4x4]

Thanks for all the help guys, ran a hot wire from the battery and she fired up. So for now I have the hot wire ran to a switch in the dash.

 

[diesel4me]

Yaaay!......glad it was that simple!...

If you use a separate switch,that might qualify as a anti-theft device also,on your insurance...

It also might cause trouble if anyone else drives the truck and forgets to turn it on before cranking though too--I've had a friend offer to move my truck for me so a plow could clear the parking lot at my apartment once,and he "forgot" to turn the switch on,and cranked it till he killed the battery!.....when I came out and jump started it with his car,the muffler blew the seam wide open,from all the unburnt gas when it lit off with a M-80 like explosion....