OK. here is my info: 1968 ranger with a 360, mild cam, edelbrock intake, 4 barrel holley with electric choke.

My truck was starting to stumble bad when starting off from a dead stop. I replaced the points because they looked pretty bad. I set the new ones at 17. Cranked the truck and set the timing to 6 degrees. I drove the truck and it acted a little better so I decided to bump up the timing. I set it to 8 degrees, and it acted better. I couldnt bump it up anymore because it was hitting the small hose from the water pump to the intake. I then decided to pull the distributer and reset it so that the advance is more in the middle so I would have room to adjust it. I pulled the number 1 plug and found TDC. I pulled the distributer out and after awhile I finally got it to line up correctly with the advance more in the middle and the tumbler pointing to the number 1 plug on the rotor cap, still at TDC. Buttoned everything back up and when I went to start it, it backfired through the carb. I tried every position by moving the advance from all the way from the right to all the way to the left moving the distributer a little bit and trying to crank it and I can not get it to fire, it will only backfire through the carb at certain points. Any suggestions?

 

Did you try talking nicely to it? You are 180 out. The piston hits TDC twice in a cycle. Once for compression sounds like you have TDC for the exhaust portion of the cycle. Rotate the crank one time lining back up on TDC and restab the distributor. If that don't work and you have already tried talking nicely to it try cussing at it. Some women like being talked dirty to.

EDIT: No need to pull the plug. TDC is the timing mark lined up on 0.

 

I lined the crank up on zero, and pulled the plug just to make sure in was at TDC. Also, when looking at the dizzy with the cap off, the rotor is pointing at the number one plug on the cap. When I try to crank it, it backfires through the carb, I am lost at this point....

 

Ok I must not have clearly stated what is wrong and how to fix it. Let's try this a couple different ways. For every one rotation of the distributor the crankshaft rotates twice. This means that when at TDC the distributor should be pointed at 1 or exactly across the cap at whatever cyclinder resides there. You are 180 off. Let's look at this a different way. Take the cap off. Rotate the crankshaft until the rotor points at your #1 cylinder. Mark something designating where the rotor is pointing. Ok now rotate the crankshaft 1 time until you align with TDC. Look at your distributor. The rotor is now pointing exactly the opposite as before. I know you are at TDC BUT you are at the wrong TDC for cyl 1. Instead of trying to convince me what you have done is 100% correct do what I suggest. Once you understand what I am talking about you will have it fixed in less than 5 minutes.

 

You were right, I was 180 degrees off. I buttoned everything up, hit the switch and she fired right up. I have the timing set around 12 degrees right now and its running good, but I cant test drive it because its trying to rain here in VA. Maybe I can get her out tomorrow for a test run. I appreciate your input and help and maybe this thread will help someone else in the future. Nevertheless, I feel really stupid right now!

 

Just for the record this is the cycle starting from the firing of the plug. Piston up plug fires, the explosion forces the piston down, at this point another cyl is at TDC firing which forces the crank down forcing the original cyl back up. The exhaust valve is open and on this up stroke the exhaust is pushed out of the cyl. Exhaust valve closes, intake valve opens and on the down stroke it sucks in more fuel/air mixture. Intake valve closes piston goes up compressing the mixture waiting for the plug to fire and we start all over again.

As you can see the piston is at TDC twice for a single cycle. As long as I am at it does anyone how the rpms are counted? Crankshaft or camshaft? I have always assumed camshaft as tachs are driven off the coil (elec) or the distributor (mechanical) but does the tach double that could thus making rpms crankshaft revolutions?

 

Glad to hear you got it running. Is the black truck as your avatar the truck? I told my wife if it is the truck and you don't get it running you don't deserve it. I was gonna send the truck police and have them take it away from you!

 

LOL, yes that is my truck. Like I said, I feel stupid not finding the problem, but I could have sworn that the rotor button was pointing towards the number one plug on the cap. All I did was pull out the dizzy and turn the advance as to where it would be centered to the front so I can retard and advance the timing. Maybe I was seeing things??? LOL, anyway, its purring now. Thanks again!

 

Zero on the dampner marks TDC, true...always pull No. 1 plug and put your finger over the hole and feel for compression to know whether you are on the compression or exhaust stroke.

 

"always pull No. 1 plug"

I guess after turning a wrench for 12 years it's not that big a deal to me. If it doesn"t start it's 180 out. Pull the distributor up, spin the shaft 180, drop it back down and lock it down.

 

The best way I have found to be sure of the correct TDC is to pull the no.1 plug and stuff a small amount of rag or paper towel where the plug screws in, so when rotating the motor when you hit compression stroke it forces the towel out.

 

All the methods mentioned work...just depends on the doer. I was taught to pull the number one plug...so that's what I tell newbie's to do...especially with these priceless old trucks.

 

(Help) I HAVE A 1971 SHORT BOX, My trouble is that someone in years past took out the colum shifter this is auto set up. They did some wiring work. There is a safety switch on the bottom of the the steering colum with 4 wires that all seem to be hot, two of the wires were cut an ran to a button on the dash. Now with that set up you turn the key on push the button and it starts right up. Here is the trouble that worked two times now I get nothing. I got power to all when key is on. The starter is good and I don't trust my self with wiring to get it right . Those 4 wires go to a plug that can be unpluged to bypass or do they need to be hooked together? Or did the ignition go out an some cracker was to cheep to buy a $35 part.

 

Well done, elgemcdif. We always feel good when we can fix a fellow mororhead's vehilce from our computer a few hundred miles away.
Buy yourself a beer on us mcdif.

 

Grub it sounds like they did a wierd bypass. I would start by getting rid of the push button. Restore the wiring to what looks to be original. Shouldn't be too rough to figure out. Match colors of original wiring. Now just for kicks check to see if it will start. Oh yes be sure to have the switch plugged in. If it doesn't don't get discouraged we are working through a process. Ok it did or did not start. Go under the hood and on the column find the shift lever. Should be sticking out of the side of the column. Now that I think about it you should have a collar on the column inside the truck where the shift lever attached. Either way you want to verify it is all the way up (park position). If it started before you will want to find a way to lock that collar in place. If it didn't start you will still need to lock it in place but we look further for the problem. Verify they have not cut the wires from the back of the ignition switch. If they have been cut repair them. If the truck still won't crank at this point I would check flow through the NSS.

If I remember correctly the ign switch sends to the safety switch safety switch decides to send or not to send to the solenoid. Verify you are sending voltage from the ign switch to the NSS. If you are and nothing is coming out of it or doing all this causes the truck to crank non stop. Crank non stop is bad ignition switch. No voltage from ign to NSS is bad ign switch. Voltage in NSS nothing out: Either the column is not in park/neutral OR NSS bad. Since you will be basically bypassing the switch no matter what you do unless you hook up linkage from the trans to teh column that controls the column simultaneously with the floor shifter you could just find the circuit you desire and build a jumper to close the open.