rythmic cut outs at 2500 RPM ??

[YY1]

The first week my 73 Satellite was back on the road, it ran great.
Then I started having a power loss at and just below WOT.
It continued to get worse until a few days ago.

In another post, I had accelerator pump issues (clip came off) and fuel pump issues (thought sure that was the main problem).

So now I'm back to...

Everything feels OK until 2500 RPM in third gear.
Then the engine feels like it's laboring, and then cuts out.

If I keep my foot still, the engine picks back up at 1500, but cuts out again at 2500 and will continue to do this until I let off.

If I let off, it will be OK until I either add moderate throttle, or get back up to 2500.

WTF?

I replaced the brain with a known good unit- no change.
I'm going to try the coil next.

I'm not really sure it's electrical vs fuel, but the clear filter is full and clean, although this is hard to verify at 2500 RPM under load.

Power braking is fine but it won't go over about 2200 RPM (converter stall?).

 

[dryheat]

My guess would be timing / advance not working properly.

 

[Zeppelin264]

My guess would be timing / advance not working properly.

This!

 

[MarPar]

distributor clamp doing it's job?

 

[YY1]

Thanks, guys.

The dist is a reman that I put in the first year I had the car (making it 3 calendar and 1.5 mileage years old).
The OEM unit was not pulling the weights back consistently and I didn't feel like tearing it apart.
It solved that problem.

I like to keep my hold downs tight enough to hold time but just barely loose enough to make adjustments without needing a wrench. I've never had a problem with it slipping unless it was way loose.
You'd think that if that were the case, it wouldn't be OK after it slipped.

Checks out OK on the timing light.

Out of gear I can rev all the way to 4K+

 

[oldbee]

I saw one once kinda acted the same way and after numerous checks I pulled top cover of carb and found a dog/cat/human hair sticking out of one of the primary jets. Pulled it out-fx'd problem, how it got there I have no idea.

 

[YY1]

OK, not coil...or brain.

Tried a couple things-

1- Held in 2nd- still got the same thing at 2500 RPM.

2- Floored it at 1800 RPM- all was fine up to about 3300, then as speed and trans started "catching up" and RPM came back down to 2500..... same thing.

Wow.

You'd think good performance above trouble RPM area might rule out fuel starvation...

I also drove down a long road at about 2350 RPM and it was just fine the entire way.

This is really perplexing.

I know there is an idle to cruise transition circuit in the carb, but is there a cruise to wide open transition? Remember it's NOT the accelerator pump.

 

[oldbee]

If you're right, then it's fuel starvation/vapor lock? Almost has to be.

 

[oldbee]

Have to remember that in higher gears you're in the RPM band a little longer in the time frame so you're pulling more out of the bowls in carb.

 

[YY1]

You'd also think a WOT from 1800 in second that's OK until RPM comes back down to 2500 would rule out advance issues.....

 

[YY1]

This is 85*, 30% humidity, right after and/or during warm up.

Hard to believe vapor lock. (and why didn't it do it in week 1?)

Brand new fuel pump.

I wish I could rig a camera to look at the fuel filter at 2500 RPM in gear.

...also doesn't do it in power brake.

 

[idrivemopar]

Have you checked the fuel pickup in the tank to make sure the sock on it isn't getting plugged up ?

 

[oldbee]

Is everything tight instead distributor? Almost sounds like plate moving around too much & changing gap on reluctor; drive it w/o vac.advance hooked up & see what it does.

 

[YY1]

Sorry. Took Sunday off...completely...from everything.

The gas tank was also replaced in 2013/14, before it went in for the engine removal.

I can't remember if I replaced the pickup, but I'm sure I wouldn't put it back in if the sock filter was nasty.
I suppose I'll pull it out again.

There was just barely any gas in it during the down time, and it was generously laced with Sta-Bil.
It had no trouble starting after everything went back together.
I love those glass fuel filters with replaceable cartridges.
That's hat's on there and the fuel is very clear.
I put on a new pump because the level was very low.
Now it is nearly full, at least when I can physically observe it.

While I had the fuel pump off last week, I put a hand vacuum pump on the fuel line and it pulled about 1/4 cup of fuel in about 5-6 pumps.

If it's fuel starvation, should I not be able to induce it bu holding the revs about 3.5-4K in P or N?

I really don't like stuff like this kicking my ***.

 

[mopar 3 B]

Get rid of the glass fire hazard filter.

 

[mopar 3 B]

Sorry. Took Sunday off...completely...from everything.

The gas tank was also replaced in 2013/14, before it went in for the engine removal.

I can't remember if I replaced the pickup, but I'm sure I wouldn't put it back in if the sock filter was nasty.
I suppose I'll pull it out again.

There was just barely any gas in it during the down time, and it was generously laced with Sta-Bil.
It had no trouble starting after everything went back together.
I love those glass fuel filters with replaceable cartridges.
That's hat's on there and the fuel is very clear.
I put on a new pump because the level was very low.
Now it is nearly full, at least when I can physically observe it.

While I had the fuel pump off last week, I put a hand vacuum pump on the fuel line and it pulled about 1/4 cup of fuel in about 5-6 pumps.

If it's fuel starvation, should I not be able to induce it bu holding the revs about 3.5-4K in P or N?

I really don't like stuff like this kicking my ***.

Answer! No
An engine under load requires more fuel to do the same rpms.

 

[droptop]

Sounds like a fuel issue to me. Have you checked the fuel pump rod? Could be worn.

 

[mopar 3 B]

Could also be that great glass fuel filter not passing enough fuel. Things hadly larger in diameter than a quarter and its not feeding a lawnmower.

 

[wagonman]

Fought a similar issue on an older Pontiac after about 100 miles and a good heat soak it would run out of power and stall. Let it cool down and good for 100 more. Sock in the tank was plugged up.

 

[YY1]

Soooo.....

I drove it over to my brother's and it perplexed him as well.

After some serious "no, it can't be that because_____" discussion, we kept coming back to "the fuel filter is full" and we both decided on tearing onto the carb versus dropping the tank.

However, on the way home it got much worse, just like it did when I replaced the fuel pump.
Basically had to idle home for 10 miles (OK, 30-35 MPH).
I pulled over and- no fuel in filter. Drop the tank.

Tearing into the tank- tuel sock was fine, rest of pickup was fine. Hose from tank to line- fine.

Removed hose from line to pump and stuck jar on end. Blew 140 psi air from back to front- got a thimble full of pink fuel. No solids, no sludge.

Put back together but also drilled out stuck "two way" valve in vent manifold.
It unstuck with a few sharp blows, but I thought it was a "one way" valve, so I drilled it out.
Turns out it's supposed to close if too much pressure goes either way. I figure the chances of that happening are pretty low, and figure better not to have the cap blow past my hand when removing it, like it had been doing.

Relocated the fuel filter to the tank side of the pump- so I can see if any crud comes through before it gets into the pump, and buttoned it back up.

20 mile shakedown and had to adjust the idle down (that's a good sign) but did fine.

Of course it did run great for a week before this all started.

Keeping fingers crossed.