Lifter Ticker

[Cdaniel]

Now for another pesky, irritating gremlin/demon that is plaguing me. I've got a few hundred miles on my recently rebuilt 289 2v, .30 over but otherwise stock. Since the initial startup it has a consistently jerky idle. Not like a hot cam or crappy carb mix, but more like a steady miss. It also has a single lifter tick on startup for a few seconds. The engine runs smooth and strong on the road. No amount of rocker/timing/carb adjusting seems to make a difference. I'm beginning to get the sinking feeling that the cam went flat or maybe it's just a single screwy lifter not doing it's job.

Any ideas guys?
Cliff Daniel
http://members.cox.net/cwdaniel/index.htm

 

[Ozsum2]

Did you replace all the lifters? Your miss could as simple as a bad wire or loose connection. Stick a vacumm gauge on it and see what the internals are doing.

 

[Great68]

I thought it was normal for lifters to tick for a few seconds upon startup, because they need to build oil pressure.

 

[Ozsum2]

I thought it was normal for lifters to tick for a few seconds upon startup, because they need to build oil pressure.

No, they are supposed to stay pumped up. The noise is a connecting push rod hitting them. Not a good thing. I've seen rods that were pointy and the rocker arm had a hole worn all the way through. Weak ones or collapsed ones "talk" to you.

 

[Cdaniel]

Did you replace all the lifters? Your miss could as simple as a bad wire or loose connection. Stick a vacumm gauge on it and see what the internals are doing.

Good point, the vac is steady at idle, about 18 inches. That would tend to point away from a faulty cam, Right?

Maybe the lifter issue could be seperate from the miss. Hmmmmmm
The wires are new but I guess that's no guarantee.

 

[Ozsum2]

Good point, the vac is steady at idle, about 18 inches. That would tend to point away from a faulty cam, Right?

Maybe the lifter issue could be seperate from the miss. Hmmmmmm
The wires are new but I guess that's no guarantee.

Steady needle is the clue. Internals are fine. Look for electrical gremlins.

 

[Cdaniel]

Steady needle is the clue. Internals are fine. Look for electrical gremlins.

Other than the obvious bad plug wire, what could cause trouble? The coil, cap and rotor are new. The dist is a new reman, with Pertronix inside.

 

[Ozsum2]

Well, I understand that the Pertronix takes a full 12 volts to fire right. Did you run a new wire from a known 12 volt source? Pull each plug wire off 1 at a time to test their condition. Be careful not to light yourself up. I supose your carb could have a partially clogged jet or some other trash in there. What is it's condition? What is your initial timing set at? Too high will make it skip at idle.

 

[Cdaniel]

Well, I understand that the Pertronix takes a full 12 volts to fire right. Did you run a new wire from a known 12 volt source? Pull each plug wire off 1 at a time to test their condition. Be careful not to light yourself up. I supose your carb could have a partially clogged jet or some other trash in there. What is it's condition? What is your initial timing set at? Too high will make it skip at idle.

I checked the voltage from the new engine harness, 10.5v while running. So I jumped a wire over from the battery, 13.5v. No change in the engines behavior. I did the plug wire drill, no smoking gun there either. They all caused serious miss when disconnected. As for the carb, I think it's fine. It's a fresh unit from Pony Carbs. Now for timing, who knows? I've been using the Pony Carb method of toss the timing light and set it by ear and vacuum. This goes against my instincts, but it does run well on the road. I've had to back it off some due to crap gas and pinging under load.

What about plugs and plug gap? I think I have them set at .035. It's been so long since I built the engine, I can't remember for sure.

 

[Ozsum2]

Your right on with the gap. Some say you can go a few wider, but it wouldn't cause the miss you are having. Pony carbs are good and they are right in their timing procedure. I have experienced that initially, you can get the timing too high with their method, but they still say if you get ping under load, to back it off untill it stops. When you first installed to carb, did you flush the system like they say? They say to turn the engine over with the fuel line in a cup or something and catch the gas. The reason being when the new carb, with it's empty bowl demands that sudden rush of fuel, it could dislodge some junk and the junk could clog up the carb. Other than that, I am at a loss. You have tried everything I would have. Sorry. Good Luck

 

[Cdaniel]

I'm just wondering if a hotter plug might help. I'm begining to think I need to have a bit more patience and give the engine more time to break in. The symptoms seem to come and go now. Before it was constantly present. I'm hoping the change from the break in oil to synthetic will help the weak lifter. We'll see.

 

[Ozsum2]

I'm just wondering if a hotter plug might help. I'm begining to think I need to have a bit more patience and give the engine more time to break in. The symptoms seem to come and go now. Before it was constantly present. I'm hoping the change from the break in oil to synthetic will help the weak lifter. We'll see.

Heat range in spark plugs depend on what the majority of the driving you do. If you do mostly stop and go city driving, then a hotter plug is desireable. If you do mostly highway, then a cooler plug is the ticket. Stock type plugs are a middle of the road. Be careful on the synthetic switch. Make sure the engine is well broke in. If it isn't broke in, the synthetic oil will glaze over on the surface of the cylinder walls and it will need to be honed down to remove it. Do you remember the break in procedure you used on the new cam?

 

[Cdaniel]

. Do you remember the break in procedure you used on the new cam?

No procedure other than the tribal knowledge of start and hold it at high revs for 10-20 minutes. Drive it at various speeds, which is what I'm up to now.

Rings still not seated? I checked the compression a while back, It was kind of uneven cold but when rechecked warm all cylinders were close to the same.

 

[Ozsum2]

No procedure other than the tribal knowledge of start and hold it at high revs for 10-20 minutes. Drive it at various speeds, which is what I'm up to now.

Rings still not seated? I checked the compression a while back, It was kind of uneven cold but when rechecked warm all cylinders were close to the same.

Yea, right on with the cam. You will get that until the rings seat. When you adjust the idle mix, by turning the screws in, do they slow the engine????specifically each screw? I'm still thinking fuel related.

 

[Cdaniel]

Yea, right on with the cam. You will get that until the rings seat. When you adjust the idle mix, by turning the screws in, do they slow the engine????specifically each screw? I'm still thinking fuel related.

Yep, the idle screws function as expected. Turned in until it stumbles backed off about 1/2 a turn. It just doesn't seem fuel delivery related to me. My experience with carb idle issues has always been an erratic idle or it plain won't idle. This miss is more constant and rythmic with the RPM of the engine.

Another good gearhead friend of mine suggested I my have an internal vacuum leak. He suggested filling the crankcase with propane to see if it smooths out.

Anyone ever try this?

 

[Ozsum2]

Yep, the idle screws function as expected. Turned in until it stumbles backed off about 1/2 a turn. It just doesn't seem fuel delivery related to me. My experience with carb idle issues has always been an erratic idle or it plain won't idle. This miss is more constant and rythmic with the RPM of the engine.

Another good gearhead friend of mine suggested I my have an internal vacuum leak. He suggested filling the crankcase with propane to see if it smooths out.

Anyone ever try this?

But any miss should be seen on the vac gauge needle.

 

[Cdaniel]

But any miss should be seen on the vac gauge needle.

I checked it again, still pretty steady, some variation maybe 1/2 a tick between 17 and 18 inches and that's after the timing was backed off a little. Of course my gauge isn't the best quality and probably not real accurate. But I would expect a problem to show up as a major fluctuation in the needle.

 

[Cdaniel]

Well, I understand that the Pertronix takes a full 12 volts to fire right. Did you run a new wire from a known 12 volt source? Pull each plug wire off 1 at a time to test their condition. Be careful not to light yourself up.

Hey Ozsum2! I'm back at this one again. Now that the manifold/ported advance mystery has been solved (right) . Seems that issue is up there with religion, politics or GD&T.

Anyhow I tested resistance on spark plug wires, read on a 20k ohm scale
1-14.4
2-11.75
3-11.6
4-12.5 (erratic)
5-8.4
6-12.3
7-10.6
8-11.6

These are stock replacement 7mm wires. The shop manual says no more than 8000 ohms per foot. They seem close except #1. The #4 wire would never stablize on a reading.

Possible cause for poor idle quality?

 

[Max Power]

Yup.

When I did the cam swap on the Mav, I had similar problems. Turned out to be intermittant arcing at the coil connections. I think ignition is probably your problem. I used the Ford Motorsports 9mm wires and they worked very nice.

 

[Ozsum2]

Hey Ozsum2! I'm back at this one again. Now that the manifold/ported advance mystery has been solved (right) . Seems that issue is up there with religion, politics or GD&T.

Anyhow I tested resistance on spark plug wires, read on a 20k ohm scale
1-14.4
2-11.75
3-11.6
4-12.5 (erratic)
5-8.4
6-12.3
7-10.6
8-11.6

These are stock replacement 7mm wires. The shop manual says no more than 8000 ohms per foot. They seem close except #1. The #4 wire would never stablize on a reading.

Possible cause for poor idle quality?

Yes, you may have found it. Swap it out with a known good wire and see. Good Luck.