84 720 Timing help

Clintman · Aug 3rd, 2003, 10:27 PM

A couple months ago my voltage regulator went out on my alternator. Once i got that fixed my truck has never realy ran right since. I took it to a mechanic that was a freind of my uncles and he said it had many vacum leaks. He fixed several of them but when i got the truck back it still didn't run right. He actually removed some of the vacum components which i just notived recently. I have replaced many parts on this truck including:
1. Head Gasket
2. Ing Coil, (only one though)
3. Dist Cap
4. Dist rotor
5. Spark Plugs
6. Spark Plug Wires
7. Intake Manifold and Exaughst Manifold Gaskets
8. Timing Guides, gears, and chain
9. Ignition Control Module ( the really expensive black thing at the bottom of the distributor ).
I have replaced all these parts and unfortuanteley taken my engine apart about three times now to make sure i got the cam and crank shatfs lined up. Yet after all of this it still will not run correctly, it will idle (although it is very rough) and it has absoultely no power. When I use the timing light i can't get the mark to get to the 7' mark or whatever it is supposed to be at. When i turn the distributor it moves from what I gues would be about 30' to only about 15'. I am really getting tired of workin on this damn truck and I really am running out of ideas. I think it might be something electrical but i do not have any idea what it would be. Please help me any good ideas at to what the problem might be would be a great help

Clintman · Aug 11th, 2003, 08:00 PM

After messing around with the vacum tubes ( witch were all f***ed up) i got the truck running pretty smooth. Although the truck is running smooth the time still will not come down to where it is supposed to be. Another thing i noticed is that if i turn the distributor to the middle of its range the engine runs its smoothest but i can't get the truck to start there. When i turn the key it doesn't even do a complete revolution, it acts like it is getting stoppe by something, like the valves are closed when the piston is coming up or something. Please help me, I need to get this thing running. Any ideas would help very much.

nissannut · Aug 14th, 2003, 11:01 AM

It sounds like at Timing issue.

When you put the chain on, did you have the head set at top dead center?
When putting on the chain there are 2 links that are a darkish color that line up with the dot marks on the crank and cam gear. If those where done right, then the next critical thing is the distributor gear. This can be realinged just by removing the oil pump with engine at tdc...

10BTDC is stock.

Just too rule out vacumm. plug the 2 sources at the front of the carb and the 3 on the carb. The vacumn diagaram is very complex on this truck. I have seen allot of screwed up ones. Problme is when you remove the air cleaner assembley mechanics have to disconnect 5 plus the rear vacum line and they cant get back on wrong.

You do not need any vacum lines connected to anything for the truck to run smooth or otherwise they just control egr, AIV, etc...

Put the engine at top dead center and remove the distributor and look at the placement of the drive gear.. it should be at 11:20 with the fat part towards the cab. If I remeber right... If it is not remove oil pump and reposition. If you are off ONE tooth you will get the symtoms you are describing.

nissannut · Aug 14th, 2003, 05:49 PM

Got an email from Clint... "Hey you were right about the ign coil fuse, it was bad. i will also make sure to check into the distributor gear, i never checked that, but i know i got the cam and crank alligned correctly. Thanks for all the help, I really do appericate it."

I have scanned the ign wiring diagram page. Let me know if you did not get it..