Really bogging down in 3rd gear

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nashvegas99

nashvegas99

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As the post says, i can cruise in second without issues. Shift to third and it boggs down. Does that sound like plugs, fuel filt, carb adjustment, etc ? New carb, runs and idles fine. Thnx guys
 
.........sounds like a fuel restriction, did u have this problem b4 the new carb....could really use more info........kim....
 
- Auto trans? 3 speed?
- Is the car revved up a lot when it shifts, or just normal RPM's and speeds and cruising?
- Does it run better in 3rd when you finally get it revved back up?
- Does it bog after shifting from 1st to 2nd?
- Is the timing setting at idle per the timing cover tab, and is timing set with the vacuum advance hose removed from the distributor and plugged, and using a timing light?
- Is this an older points distributor?

I would be thinking carb's power valve not working (you have a Holley 1920, right?), ignition timing (perhaps mechanical or vacuum advance not right), overall timing (basic ignition timing, or timing chain, but not likely just the chain as it would be doggy off idle in 1st and 2nd too), or fuel restriction. Answers to the set of questions above will help narrow this down.
 
Could use more info. I don't even know what country your car was manufactured in. If you have a spare carb, change it out. If you still have the problem, at least you have a starting point. We are all assuming your exhaust pipe isn't crushed or plugged, air cleaner is clean, fuel pressure is good, plugs are clean and properly gapped, wires are not cross firing, cap and rotor are good, gas is fresh, brakes are released, etc. List is long.
 
nm9stheham said:
- Auto trans? 3 speed? 3 speed

- Is the car revved up a lot when it shifts, or just normal RPM's and speeds and cruising? I have to rev it up going from 2nd to 3 rd

- Does it run better in 3rd when you finally get it revved back up? No, it still is boggy in 3rd when it gets going

- Does it bog after shifting from 1st to 2nd? No, honestly it jerks and bumps from 1st to 2nd

- Is the timing setting at idle per the timing cover tab, and is timing set with the vacuum advance hose removed from the distributor and plugged, and using a timing light? Yes its set on the timing tab using a light set at 8 deg. I cant remember if iplugged thehose when i timed it

- Is this an older points distributor? Yes, new points replaced several months ago but part of what i plan on doing is new points

I would be thinking carb's power valve not working (you have a Holley 1920, right?), ignition timing (perhaps mechanical or vacuum advance not right), overall timing (basic ignition timing, or timing chain, but not likely just the chain as it would be doggy off idle in 1st and 2nd too), or fuel restriction. Answers to the set of questions above will help narrow this down.
Click to expand...

Its a new carb. Not a holley. I plan on replacing plugs again i had lots of touble several months ago getting it to fire and run...180 out, etc, timing back fire. New cap and button. I am oing to replace the fuel filter again and reblow outthe lines. New tank also.

Thanks for the help. Merry Christmas
 
Timing chain may have slipped or you may have a restriction in the exhaust..... Try advancing the timing and see if it helps.
 
I swear, some these posts are like the ring toss in a circus.
A giant table of possibilities and everyone throws their ring.

Just for the heck of it I toss mine at the "starving for fuel" bottle with Oldkimmer and see if I can land on top of his ring.

Still it could be a bad module, coil, plug/plugs, plug wires, timing, distributor, rotor, fuel, carb and a few select other things.
 
Well, you gotta start somewhere, I suppose. And with points, no ignition module of course.

If the OP can confirm, it basicaly only runs Ok at higher revs in 2nd? I would certainly be looking at the points gap; have them close up will cause symptoms similar to this. Also, when you put in the points last time, did you put the correct lubricant on the points and the points cam on the distributor shaft? You can't use just anything; the points rubbing block will wear down and close the gap, and if you use certain lubes like lithium, it can actually wear the sharp angles off of the shaft cam very rapidly.

Next on my list would be a vaccum leak.

Then timing. That is just an ordering of things to check, not that it is any one in particular.

If you are planning to do the tank and lines any way, it is certainly an excellent idea. I recall this car had set for quite a while.
 
Thnx all. So i took a look at the dist again and turned over the engine. I think a small part of the issue is the points cam is wroe down. There are only small "humps" not sharp ridges left and i think that they arent even wore downevenly.
Can the points cam be removed and replaced?
 
nashvegas99 said:
Thnx all. So i took a look at the dist again and turned over the engine. I think a small part of the issue is the points cam is wroe down. There are only small "humps" not sharp ridges left and i think that they arent even wore downevenly.
Can the points cam be removed and replaced?
Click to expand...

They were never very sharply pointed when new. Look either directly above or below where the points rub on the cam. There should be virgin metal there where you can see if the lobes are worn. If you have a dwell meter, that will give you a more accurate reading than feeler gauges.

For something like this I always go back to basics. have you done a compression check yet? Could be a burned valve for instance.
 
If not a Holley, and an early A, most likely a Carter BBS carb (why not tell us all that?). Good, since Holley 1920's are notorious for plugged idle circuits -> lean idle. Still, sounds like a lean idle, but verify. Close the choke by hand while idling and see if the engine likes that. If so, search for a broken vacuum hose (can often hear it, start plugging them off) or a leaking intake.
 
For comparison to yours to see if it worn, here is a distributor with the points cam in good shape. If yours are worn, then it would likley be best find a good used one or a rebuild.
 

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Something to remember when troubleshooting a drivability problem, is that in most cases, a weak ignition will show up under periods of heavy LOAD. The engine does not have to be turning a lot of RPMS.

In the most basic way to explain it, when you have an engine under increased load, there is a greater demand on the ignition system. There's WAY more to the explanation, but essentially you have to have spark energy, spark duration( dwell, coil saturation) and ignition timing in parameters to avoid breakdown under load.

A fuel starvation, however, tends to show itself more at high rpms. The float bowl simply drains faster than it can be replenished. Lugging at low rpms will usually be trouble-free with fuel supply problems, where lugging with ignition issues will rattle your teeth out.
 
Do we know what were working on yet? I mean, Im guessing its an early A(pre 67) with a 3 spd manual trans, a Carter carb and points, with likely, 2.76s, or so, out back. Sound close?
- IIRC, Carters have metering rods with their attendant springs.
-The lobes on the point cam do not have to be sharp.Its highly unlikely the lobes are significantly worn. I have seen many high mileage engines with well functioning point cam lobes.And, yes that part can be replaced.Bear in mind that the point on the cam is not a functional part of the system. the points open well before that part comes around to the rubbing block, and close well after. That point could have been manufactured well rounded and not affect the operation of the points. The status of the rubbing block is of far more significance. But, as long as a proper point gap is achievable, and more importantly, a proper dwell measurement,then all is well. Once the dwell falls too low, the coil saturation suffers and so does the ignition performance, under load.
 
Hmmm, my last post did not take..... Tyler's descriptoin seems to me to be a pretty fair distinction between weak ignition and weak fuel.

The points distributors through 1969 should work. Not sure if the advance curves changed much, but I suspect just about any one would work for your car.

I will agree that the points cam on the distributor is not a common issues. But wiht fewer drivers knowing how to take care of them, then this wil be a more common problem. If the OP observes that the points on the distributor cam are worn unevenly, then it has become an issue. It will be difficult if not impossible to have uneven wear and not have the points operation erratically from cylinder to cylinder. Not only will the dwell vary but the actual spark timing cylinder to cylinder will vary.

He should compare the cam points carefully and if they are really erraticly worn, then it is time to replace that part. It may not be the cause of this present set of issues, but it needs to be corrected. If they are not highly worn or not worn unevenly, then move on to another of the causes mentioned. Vacuum leak (since the carb has been worked on in the last few months), and fuel (since that is such a common issue with old tanks).
 
One would think that a vac leak bad enough to cause the OP's issue's at high engine loads would make it not even run at all at idle, or low R's.
I still think fuel supply volume is the problem. :)

Pump
Filters
Tank pickup
Sucking air at a rubber section of the line.
 
TylerW is right-on in post#16. It is harder to spark at higher cylinder pressures, which occurs at WOT at low speeds, like going uphill or an interstate on-ramp. My 96 Voyager 2.4L would start missing badly then. Lower the plug gap slightly fixed it, per a Chrysler TSB for the 2.4L turbos. Same deal in my 64 Valiant when I wired +12 V to coil+ to drive it home. It ran fine at idle but starting missing bad >40 mph in 3rd as the coil got real hot.

Re distributor. Better to get an electronic distributor (~1972+) and wire to a GM HEI 8-pin module/coil (85-95 V-8). Look for Aspen, Volare, trucks, & vans at junkyards. If lazy, buy on ebay an TrailBeast kit. You could also retrofit a Pertronix or Holley XR700 to your existing distributor.
 
TrailBeast said:
I swear, some these posts are like the ring toss in a circus.
A giant table of possibilities and everyone throws their ring.

Just for the heck of it I toss mine at the "starving for fuel" bottle with Oldkimmer and see if I can land on top of his ring.
Click to expand...


Xs2
 
Thanks guys. I went to start her the other day and the starte is burned out (i believe). I think the solenoid on the starter is shot. Wouldnt cross over and jump start. Just kind of sizzled when i turned key over. Im gonna have to get a new starter before i can do anything else. Thnx again
 
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