72 GMC no spark

[ImportSlayer503]

hey guys, im a ford guy by origins and really dont know much about chevys, carberators, and pretty much anything other than a SEFI 5.0 302 SBF.


but, i have 2 GMC 2500's, one is a 72 and the other a 71. the 72 is in really good shape and the 71 i got for a parts truck.


2 problems though...

the 71 has a Goodwrench 350 in it, at least it says that on the valve covers, i was wondering if anybody could give me any hints to identifying it positively. the 72 has the original 350.


i am trying to get the 71 started, i have no spark, coil is good, and the distributer cap and rotor looks like it is brand new but the truck hasnt started in years. like i said i have zero spark at #1, what should i look for in order of probability?

 

[Alex Ayala]

Do you know if the truck was running when it was parked?

Pull the coil wire from the cap and hold it about 1/4" from a ground with some insulated pliers or a dry rag and have someone crank thhe engine or use a remote starter switch to see if you are getting a spsrk from the coil.

If you have a spark check to make sure the distributor is wired correctly to each spark plug.
The firing order, which should be cast into the intake manifold, for the chevy small block V8 is 1-8-4-3-6-5-7-2.

If no spark, pull the distributor cap and check to see if the distributor turns when you crank the engine. If not then your ttiming chain or gear(s) could be bad. Mine went out a while back and left me stuck in traffic.

It's funny how some people seem to think if they blow their horn long enough that will somehow fix your car and make it start! Lickily I had a couple of good guys pull over and help me push it out of the road.

Good Luck

 

[drabo]

To find out what motor you have find the VIN and run the numbers on a web site. The VIN is stamped on the rear right side of the motor. It might be hard to see while it is in the truck. Another way is to pull the oil pan and measure the cylinder. 4.00-4.60 is a good sign it is a 350 block.

 

[dvalentine]

The engine serial number is stamped on the LEFT side of the motor, just below the cylinder head, on the bell housing/transmission flange mount. Flash light and mirror make it easier to read AFTER any crud is removed.

No spark; Start with replacing points and condensor, rotor and cap. Check for a burned ballast resistor wire off the distributor. ( on your's, it may be a wire running down to the starter motor.) Check to make sure you have a good ground to the motor.

Val

 

[texascowboy]

hey guys, im a ford guy by origins and really dont know much about chevys, carberators, and pretty much anything other than a SEFI 5.0 302 SBF.


but, i have 2 GMC 2500's, one is a 72 and the other a 71. the 72 is in really good shape and the 71 i got for a parts truck.


2 problems though...

the 71 has a Goodwrench 350 in it, at least it says that on the valve covers, i was wondering if anybody could give me any hints to identifying it positively. the 72 has the original 350.


i am trying to get the 71 started, i have no spark, coil is good, and the distributer cap and rotor looks like it is brand new but the truck hasnt started in years. like i said i have zero spark at #1, what should i look for in order of probability?

try checking the module its under the rotor mine went out on me and after replaceing everything else sent it to shop and it was a bad module.