Is my cam off 180* ?

[yellow85cj]

Had a previous thread with my timing problem. http://www.jeep-cj.com/forums/f2/vacuum-advance-problem-28683/

After fooling with it for hours, resetting the distributor countless times, the only thing left was the cam.

So here's what the cam/ crank gears look like. The cam gear mark is 180* out from what the FSM shows.

Is it possible the the engine would run with it 180* out? Just couldn't get it timed correctly, with or without vac advance. At higher rpm's would miss and backfire, no real power. Ran fine at low rpm's set at 8*. And at lower advance timing, even at 0*

Am using the large cap and rotor so got a cheap cap and cut a hole above the #1 contact. With the timing light the rotor appeared to be firing between #1 and #4, never could seem to get it close to the #1 contact.

Yes, it is at TDC as the cork really popped when I cranked it to the right spot on the balancer.

Any opinions?

 

[caveman]

The engine is on the exhaust stroke rather than the compression stroke. If you turn the engine over one revolution the marks should line up. I believe your problem is in the distributor or maybe dirt in the carb.

 

[yellow85cj]

No, not the distributor, tried with one new, one reman'd and one off a 1982 AMC 258 i6 / 4.2l . (spare engine)

Would the cork I put in the plug hole have popped out on the on the exhaust cycle? I'll put the cork back in and give it a turn. Guess the next step would be to pull the valve cover and watch what is happening.

Carb is new NOS. Why would the carb cause it to misfire/backfire?

Last time I had it started and started rev'ing it up, it seemed to be firing way below timing mark and way above, bouncing around. (used timing light to watch)

If I set the timing to 0* the rotor was firing before the #1 contact, at 650 idle. According to a chart in the FSM centrifugal advance should not start until 1000 to 1100 rpm.

 

[Lumpy Grits]

IF the cam marks do line up after 1 more engine turn. You should be GTG.
The dizzy on the other hand sounds like it is miss-indexed on the cam gear by at least 1 maybe 2 teeth.
"Carb is new NOS. Why would the carb cause it to misfire/backfire?" Because the accelerator pump and gaskets are dried out and the carb has sat on a self for 32+ years. The carb will need to be tuned to your engine and altitude. Have you at least confirmed the 2 idle mix screws are turned out the EXACT same amount?
LG

 

[mtnwhlr]

I hope you did't run any old bad gas through it when you first got it running.

 

[yellow85cj]

Mntwhlr- fresh gas, new tank (clean)

Lumpy Grits - caveman - When the marks are aligned, piston at top (checked with straw) one turn of crank , half turn of cam gear, cork pops out. Does this not mean that it is in compression stroke with piston at top? Rotor should be (and is) at the #1 contact ?

Lumpy Grits - Carb was locally purchased from a one man/one BIG dog shop. Been around for years. He said it was checked and was good to go. I have trust in him. But then there is that verify thing.

Idle mix screws are at same point as well as my eyes can see when I counted turns from full in position. Though the plugs are pretty dry black around the insulator. Electrodes are clean.

Have tried dist in several different gear tooth positions, no joy.


With one more full turn of the crank, half turn of cam gear, no cork pop, and crank/cam gear marks are aligned. Does this not man that piston is at top of exhaust stroke?

So, the way it should be is that when the marks are aligned, the piston should be at the top of compression stroke. When turning the crank (coming up on alignment marks) the cork should pop. Rotor should be at the #1 contact.

When the marks are like they are in the pic, the piston should be at the top of the exhaust stroke. When turning the crank (coming up on the marks at opposite sides as in the pic) the cork should NOT pop. Rotor should be, well somewhere else, not even close to the #1 contact.

Asking this way because this thing has me all twisted.

If above is correct, mine is doing the opposite.

 

[Lumpy Grits]

Try cranking the engine and have someone pour a shot glass full of gas into the open carb. Does it fire off??
Take the top part of the carb off and check the float level. You can run a Carter without the top section in place.
BE CAREFUL!
LG

 

[yellow85cj]

Try cranking the engine and have someone pour a shot glass full of gas into the open carb. Does it fire off??
Take the top part of the carb off and check the float level. You can run a Carter without the top section in place.
BE CAREFUL!
LG

Will have to wait on that one till I get the timing chain problem decided. Might just take the carb off and bring to the shop to be checked.

 

[Lumpy Grits]

Please keep us updated, and best of luck to a simple fix!
LG

 

[yellow85cj]

Problem solved.

Well after trying everything I could think of and trying everything others thought from carb adjustments, to vacuum canister adjustments to changing the distributor rotor to a different angle, to pulling the timing cover off and verifying the cam was installed correct, to trying 3 different distributors (new, reman'd and old), verifying the wire on the MSD box was cut to set it for a 6 cyl. I found the problem.

Never could figure out why it was firing almost closer to the #4 contact than the #1 even when the timing was set to 0.

As a last resort I picked up an stock ICM. A little rewiring to get it hooked up, and fired it up. Warmed up, set the timing to 8*. Ran great. Hooked up the manifold vacuum and it didn't go crazy.

No more misfire, at any speed, pulls great, runs strong.

Guess I'm going to have a chat with MSD.

 

[Belizean]

So the MSD was bad from the get go ?

 

[yellow85cj]

Looks like it was. Same problem from first start on rebuilt engine.

 

[Belizean]

Wow I love mine. Hot spark and makes mine run & idle great.

 

[slomo]

Mntwhlr- fresh gas, new tank (clean)

Lumpy Grits - caveman - When the marks are aligned, piston at top (checked with straw) one turn of crank , half turn of cam gear, cork pops out. Does this not mean that it is in compression stroke with piston at top? Rotor should be (and is) at the #1 contact ?

Lumpy Grits - Carb was locally purchased from a one man/one BIG dog shop. Been around for years. He said it was checked and was good to go. I have trust in him. But then there is that verify thing.

Idle mix screws are at same point as well as my eyes can see when I counted turns from full in position. Though the plugs are pretty dry black around the insulator. Electrodes are clean.

Have tried dist in several different gear tooth positions, no joy.


With one more full turn of the crank, half turn of cam gear, no cork pop, and crank/cam gear marks are aligned. Does this not man that piston is at top of exhaust stroke?

So, the way it should be is that when the marks are aligned, the piston should be at the top of compression stroke. When turning the crank (coming up on alignment marks) the cork should pop. Rotor should be at the #1 contact.

When the marks are like they are in the pic, the piston should be at the top of the exhaust stroke. When turning the crank (coming up on the marks at opposite sides as in the pic) the cork should NOT pop. Rotor should be, well somewhere else, not even close to the #1 contact.

Asking this way because this thing has me all twisted.

If above is correct, mine is doing the opposite.

Plug picture is blurry. What I see is a rich main jet, dirty air filter, choke staying on to long, float height to high ect..... Can't read the electrode for the plug heat range. Looks rich all around. Weak ignition will also help cause this rich condition. Faulty high resistance plug wires are on this list.

slomo