Where is my power?

[Dartnut]

One of the first things to consider is the fuel.
Is it fresh and from a reputable dealer?
If it's not, then that is your first step.
The second is the timing.
Is it advanced enough?
As in with fresh gas advance it until it pings on acceleration, the back it down a few degrees.
Forget about factory settings.
Check to see if the timing chain has jumped a tooth or two.
Third is the exhaust system, is there any restrictions throughout the whole system?
Fourth is the ignition and spark plug wires etc., they have to be in good condition.
Last would be the p.c.v. valve and the carburetor settings.
Your factory air cleaner is fine as long as the filter isn't plugged.
If you're worried about this issue, remove it and take it for a short drive and note the difference if any.
Same with the muffler.
Before you spend money on this and that, you can do some easy checks that don't cost you any money to narrow it down.
Also check for vacuum leaks, a no cost thing that will help you narrow it down...

I have had a lot of slant 6 cars (and trucks) that I drove regularly with no issues and had decent power other than a '81 Dodge truck that was a dog no matter what I did with it.
It had the lean burn on it and the engine was worn out to boot.
I put a good engine in it that I had and eliminated the lean burn, and it felt like a new truck.
Honestly, it felt like it had more than twice the power than it did before!

Finally, about the clogged exhaust system, I have a small story to tell.
Back in the early '90s I bought a '69 Coronet R/T 440 4 speed that was sitting in a storage shed for years with a bad clutch.
I replaced the bad clutch and took it for a drive, and it was sluggish and had very little power.
It was stock other than headers and electronic ignition.
I got pissed off with it after checking compression and timing, the whole works.
Then I got it out on a highway and did some full throttle blasts because of the frustration.
It went bowww...waah and it took right off like it should!
So I thought to myself what just happened?
It was a dog and now it's a screamer!
I ran it through the gears a few more times and it went like hell, like it should have in the first place...
Upon returning back to where I ''cleaned it out'' there was a pile of dead mice and debris used as nests on the road that they made in the exhaust from where it was sitting for so many years.
So, you never know...

 

[frige]

Ok I replaced the muffler and while I was at it I replaced the leaky trans pan gasket. Took her for a ride and she has more power. Not scary power but I did get her up to 65 up on the farm road. Then it died. Coasted into a parking lot and she just spins. Of course I didnt bring tools as I wasnt going over a mile or so. Checked the carb and it seems to have fuel. All the wires are hooked up. Tried her again and got a little action I held the throttle to the floor and she fired up. Got her back home still doesnt run quite right but didnt die. I noticed the fuel filter is really hot and the fuel in boiling inside. If fact the filter has come unglued inside. The filter was there when I bought the car but I did change it. So fixed one problem now found a different problem.

 

[slantsixdan]

the fuel filter is really hot and the fuel in boiling inside.

Because it is not located where it's meant to be—it's directly over an exhaust manifold runner, so yeah, it's gonna get real hot—and it's not orientated the way it's meant to be (vertical to 45°, not horizontal), either.

Do the fuel line mod with a new, metal filter. Given the condition of this one, I'd go pay some more careful, thoughtful attention to the carburetor. Your power valve ("step-up assembly" on this Carter BBS) and related circuit might not be operating properly. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

 

[frige]

If its not one thing its another lol. So I ran the new fuel line and started the engine to check it out and fuel started pouring out. I figure I didnt get the hose tight, but no the fuel pump died. Took a couple of days to get one from the local parts house. I got it installed and took her for a ride. Still no power. Ok so what is the next step? I will check compression when I get home. Oh I also installed the mopar pcv valve and grommet.

 

[slantsixdan]

Have you checked to make sure your transmission kickdown linkage is intact and working correctly? If parts are missing or it's adjusted too short, then your trans is short-shifting into 3rd and yeah, it'll be gutless. Try manually shifting 1-2 at about 15 mph and 2-D at about 30 and see if it feels markedly different. Maybe also pull the trans fluid dipstick and see if it smells burnt (=transmission slipping and turning your power into heat instead of scoot).

Do you have a tachometer? Because a torque converter stall test is on the to-do list.

New fuel filter and line look a lot better. As to that fuel pump: pretty good odds you'll have to do it again soon; see here.

 

[TT5.9mag]

How about a compression test?

 

[frige]

Funny I was just doing a compression test. Number 2 is a bit low but may be a stuck ring.

 

[TT5.9mag]

Funny I was just doing a compression test. Number 2 is a bit low but may be a stuck ring.

View attachment 1716396310

Not great consistency but honestly better than I thought it would be. Not the source of your low power imo.
Check the damper for an accurate TDC next.

 

[RustyRatRod]

Compression could be more consistent, but that's good for a slant 6. Did you ever verify you're getting full throttle with the gas pedal?

 

[frige]

Compression could be more consistent, but that's good for a slant 6. Did you ever verify you're getting full throttle with the gas pedal?

Yes I checked it earlier. It has full movement. When you are on the road the only difference full throttle makes is a change in tone and it will downshift.

 

[Ricks70Duster340]

It may just be the camera angle, but your #6 plug looks a little sooty. Also, have you put the car into the air and verified you don't have any brakes dragging? Perhaps even remove the driveshaft from the rear end and spin the tires back there to ensure everything is spinning freely.

 

[KosmicKuda]

I may have missed it but have you checked for timing chain stretch?

I have to give Mr. frige credit!

Too many times we see stubborn people ignore everything recommended but he's doing a great job trying to improve his performance.

Nice car by the way!

 

[Killer6]

Yes I checked it earlier. It has full movement. When you are on the road the only difference full throttle makes is a change in tone and it will downshift.

When You said fuel was pouring out, You mean the pump diaphram vent hole? If so, fuel went down into the crankcase, it always does. Sounds like the main jet/booster nozzle is restricted somehow at this point, My '69 Custom Cpe hit 95mph on Hunter stretch with two passengers, bone stock 1920 1bbl 225 w/a Cherry Bomb, lol....

 

[RustyRatRod]

Yes I checked it earlier. It has full movement. When you are on the road the only difference full throttle makes is a change in tone and it will downshift.

Ok, so just so we're CLEAR and on the same page, you got someone IN THE CAR to hold the gas pedal to the floor while you checked to see if you were able to open the throttle at the carburetor anymore? Is that what you did?

 

[1WildRT]

 

[RustyRatRod]

View attachment 1716396615

You keep dat chit to yerself. LOL

 

[1WildRT]

You keep dat chit to yerself. LOL

This car came stock with a /6..... It took a long time to reach 60 MPH.... And it wouldn't spin the skinny tires in the rain.... I fixed it....

The 340 & the TKO work great together...

 

[slantsixdan]

Ok, so just so we're CLEAR and on the same page, you got someone IN THE CAR to hold the gas pedal to the floor while you checked to see if you were able to open the throttle at the carburetor anymore? Is that what you did?

If that's what he did, and the linkage is blocked somewhere, then he still wouldn't be able to open the throttle more at the carburetor (because blocked). The idea is to look down the carb throat and make sure the throttle plate is damn near vertical while someone else has their foot on the accelerator on the floorboard.

 

[frige]

Yes I had my buddy look down the carb with a flashlight to verify it is getting full throttle. I rebuilt all the brakes and the driveshaft and I can push it by hand. I am leaning towards timing. When I get help I will check tdc. Its hard to see the timing mark with the a/c compressor in the way.

 

[nutz]

Advance till see pings then back down till it gone ...she how she runs

 

[frige]

When You said fuel was pouring out, You mean the pump diaphram vent hole? If so, fuel went down into the crankcase, it always does. Sounds like the main jet/booster nozzle is restricted somehow at this point, My '69 Custom Cpe hit 95mph on Hunter stretch with two passengers, bone stock 1920 1bbl 225 w/a Cherry Bomb, lol....

If the timing works out ok I wil start digging back into the carb. Although the plugs dont show lean. The carb is built out of 3 carbs and took me forever to get it working. Im pretty sure I got it right.

 

[barbee6043]

I am sure someone will mention is timing advancing?
Play with initial timing by ear, see where it goes?
I have brought many old cars back from the dead over the decades. carb and/or dist. were my issues 99% of the time.
I have had slants so wore out, that to get them to even run the first time, I had to pour a q. of oil down the sucker to get any compression!

A slant is not a road rocket anyway.

 

[frige]

Success. So I checked tdc but to be honest I just cant see the tab because of the a/c compressor. But I could see it was close. The distributor was turned all the way ccw to the stop. I turned it cw and the engine stalled. Ok so that retarded it. I pulled the distributor and adjusted the tab halfway underneath the Body of the distributor. It had not been moved in decades as it was caked with grease. Reinstalled and turned it all the ways ccw to the stop and she runs much better. I dont know exactly where the timing is but I can run on the highway with the a/c on. I will put some miles on her and probably dial it in later.
Thanks everyone.

 

[MDchanic]

Success. So I checked tdc but to be honest I just cant see the tab because of the a/c compressor. But I could see it was close. The distributor was turned all the way ccw to the stop. I turned it cw and the engine stalled. Ok so that retarded it. I pulled the distributor and adjusted the tab halfway underneath the Body of the distributor. It had not been moved in decades as it was caked with grease. Reinstalled and turned it all the ways ccw to the stop and she runs much better. I dont know exactly where the timing is but I can run on the highway with the a/c on.

Is the timing correct? Or retarded?

... actually check if the timing is advancing.

If you timed it to factory specs, bump it to about 8° BTDC as a start.

I checked the timing and it was right on spec and the advance is working properly.

One of the first things to consider is the fuel...

The second is the timing.
Is it advanced enough?
... advance it until it pings on acceleration, the back it down a few degrees.
Forget about factory settings.

Advance till she pings then back down till it gone ...she how she runs

I am sure someone will mention is timing advancing?
Play with initial timing by ear, see where it goes?

Maybe you should have listened to 413 when he responded to you almost immediately after you posted your question.

Or any of the five people who recommended the same thing after him.

And what did you actually do when you "... checked the timing and it was right on spec"?

Congratulations on getting it fixed! Now go and enjoy it!

– Eric

 

[Slugfarm]

Maybe you should have listened to 413 when he responded to you almost immediately after you posted your question.

Yeah, but just look at all the cool stuff he got done along the way.