72 GMC 1500 won't start after tune up

[revmbw]

Hey gang...newbie here. we just spent a couple of days working on my 1972 GMC 1500 Super Custom with a factory 350 engine. We replaced the plugs, wires, cap, points, rotor, manifold gaskets, transmission gasket and filter, fuel filter, air filter, pcv valve and of course an oil change. the truck was running before we did all this and now it will not start. I am very new to working on these trucks and am excited about what I will be able to do, but need a little help here and there. I would love some input. I think that it may be the ground wire, but am not sure...we did not mess with either of them, but they are both disconnected and am not sure where to reconnect them to.

Any help would be appreciated...thanks a million!!!!

[HavinSomeFun]

What ground wires are you talking about? also, most people do not gap the points correctly when they change them or don't know how and the engine won't fire.

[revmbw]

There are two ground wires attached to the fire wall that are not connected. they are on the right and left side of the engine. Also...I did not gap the points...not really sure what that means or how to do it. Like i said...i am a newbie...

[89 crew]

I agree, check the gap on the points. I have run in to points with plastic on the contacts that stop all fire.

Did it run before? If so then you know you broke it. look at what you did and around for unhooked wires. It is easy to knock a poorly made connection apart.
If nothing is found unhooked, and the points are working right, then I would put the old parts back on starting with the cap.

[HavinSomeFun]

The ground wires will attach to the engine somewhere. I have seen them on the valve cover bolts and manifold etc. The ground isn't the problem. It is your points. It is impossible for me to describe it on here. Maybe someone will step in or perhaps it is in the FAQ section. Its not hard to do with a little instruction.

[revmbw]

to 89 crew...it did run before so i know i broke it...The truck is in rough shape and just trying to do some of the small necessities for now...so it is totally possible that we knocked somehting off when we were working on it.

How do you check the gaps on the points...on the plugs I get, but not sure on the points...

also, does the transmission pan need to be torqued, if so how much and if not, how tight to i make the bolds...i am seeing some leakage but i do not want to smash the gasket too much...this is my first project...thanks for the help...

[LockDoc]

-
If you didn't gap the points that is probably your problem. They are most likely not opening so you get no spark to the plugs. You may have to get someone to help you if you have never done it before.

Here are instructions:
http://home.earthlink.net/~goodspeeds/POINTS.HTM

LockDoc

[revmbw]

thanks havin some fun...i will check it out...

[revmbw]

sounds like you all agree that it could be gapping the points...i will check that out...

[HavinSomeFun]

I sent you a PM with a link

[Project71gmc]

Originally Posted by revmbw

There are two ground wires attached to the fire wall that are not connected. they are on the right and left side of the engine. Also...I did not gap the points...not really sure what that means or how to do it. Like i said...i am a newbie...

well u need to adjust dwell and points. specs (if i remeber right) Point Dwell 28-32 Deg. Point gap 0.019 and as far as i remeber there is a window door on the front of the distributor takes a hex to turn it not sure size.. sorry if not enough info to help but i not used points in years lol best thing to do is go get a hei Hope this helps some Tommy

[revmbw]

you guys rock!!! Thanks so much for the help...this will become my first stop from now on before i begin any other projects. I will gap the points and thanks to HavinSomeFun for the PM and to Tommy for the gap info...i really really appreciate it guys...i will post some pics in a week or two so you can see the project...thanks again!!!!!!!!!!!!!!!

[revmbw]

thanks lock doc for the web page...i appreciate it!!

[swamp rat]

ya might give some concideration as to wether or not ya indexed the distributor correctly and the roter is pointing to the correct #1 plug wire. Also check your firing order and that the wires are installed to the correct locations.

You failed to mention if the truck fores at all spits or sputters, or is nust not doing anything but turning over.

[89 crew]

For the tranny pan gasket, I just use a nut driver and take them firm but not too tight. It has been a long time since I looked at the torque spec but I think it is something like 12 inch lbs? (NOT FT/Lbs!) That sound about right to everyone?

[Luvlegs]

I swear I posted this earlier.... anywho - is the HEI new to the truck? Any chance you are using the old points supply wiring? That drops the voltage to 9v I think..... anywho, for what it's worth, ya gotta have a good 12v to the HEI.

[revmbw]

No Hei...old points and distributer...thanks for the info though...i got the truck running yesterday...gapped the points and now will just time it Thursday...thanks again everyone...

[mnunn454]

Like most others above, I'd suspect points. Best way to tell if they're making/breaking properly is with one of those 12V test lights. Ground one side and put the other (pointed end) on the hot side of the points. Does the light go on and off when you crank the engine over? If yes, and if there's about 16 to 18 thousandths of clearance when the points are open, then I'd suspect the coil may be wired backwards (easy to do).

Next is I'd recheck the rotor to make sure it's contacting properly and not 180 degrees out. Then I'd make sure the plug wires are all installed correctly (1-8-4-3-6-5-7-2 in a clockwise direction if it's a V8).

If everything checks out ignition-wise, are you sure it's getting fuel?