Jake Fleming
New Member
Ok so after being almost gone earlier the symptoms came completely back pretty suddenly. So I’m thinking a new timing set and a new carb.
Drivability issues, can’t tell if rich or lean
- Thread starter Jake Fleming
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Jake Fleming
New Member
Checked and the timing has Not moved so the carb is the main culprit
Once, a state polic e car came into the local Chry dealership while I was there one afternoon, back in the middle '70s. The complaint was that it wasn't running right. The old-line Chry service manager went out, loosened the distributor hold-down bolt, and twisted the distributor one spark plug wire's worth in the advance direction. It ran better. The diagnosis was "jumped time". If it does jump time, it will be much harder to start as the distributor is now very retarded from the normal situation.
The base timing should be more like 12.5 degrees BTDC, but that shouldn't make a huge amount of difference, but a little. I used to run my '66 Newport 383 2bbl at 15 degrees as a normal situation, but then we also put premium fuel in it, as that was what it liked, even at the normal 12.5 timing spec.
Is the gas cap one like needs to be on it? Not just to hold the fuel in, per se?
There used to be methods to check for timing chain "slack" by marking the balancer and moving the crank with a breaker bar. I've only read of that, not seen it in use. If the timing chain has never been changed, that you know of, then it might be a good insurance issue to replace it. My pref is either a Cloyes Plus Roller chain set of the similar Mopar Perf roller chain set. But if the car will start and run with what's in there, I doubt that's the cause of the issues you are having.
I replaced the WWC3 on my '66 Newport with a '70-spec Holley 2210 2bbl. Ran better as it has a better venturi design and just a more finessed design. It is ALSO susceptible to the air horn warpage, but Chry/Holley did a "bridge kit" to push the air horn back down straight so the air horn gasket would seal. The '72-spec 400 2bbl carb might have a touch leaner calibration, but not a lot. The '73 versions were set-up for EGR and were dubbed 2245 as a result. Use the THICK OEM base gasket, not the thin one which might come with the carb.
Hopefully, the carb kit you got had the thick gasket, too! The replacement Holley I got had one, too. But after a while, I noticed the idle would bet a bit unsteady. I'd get my wrench out and retorque the base plate nuts, about a 1/16th turn. Then the idle got smooth again. After the third time that happened, I got an OEM thick base gasket (with the metal bushings in the holes) and problem solved.
In a prior thread, somebody mentioned that Autoline rebuilders knew about and compensated/fixed the air horn issue on the Holley 2210s. I take their word for that.
Other than the air horn warpage issues and the long-term "accumulation" issues in the venturi tubes, or possibly wear issues in the accel pump well and throttle shaft, just not much to go wrong with those carbs. I presume the choke pull-off is still working?
Just some thoughts,
CBODY67
The base timing should be more like 12.5 degrees BTDC, but that shouldn't make a huge amount of difference, but a little. I used to run my '66 Newport 383 2bbl at 15 degrees as a normal situation, but then we also put premium fuel in it, as that was what it liked, even at the normal 12.5 timing spec.
Is the gas cap one like needs to be on it? Not just to hold the fuel in, per se?
There used to be methods to check for timing chain "slack" by marking the balancer and moving the crank with a breaker bar. I've only read of that, not seen it in use. If the timing chain has never been changed, that you know of, then it might be a good insurance issue to replace it. My pref is either a Cloyes Plus Roller chain set of the similar Mopar Perf roller chain set. But if the car will start and run with what's in there, I doubt that's the cause of the issues you are having.
I replaced the WWC3 on my '66 Newport with a '70-spec Holley 2210 2bbl. Ran better as it has a better venturi design and just a more finessed design. It is ALSO susceptible to the air horn warpage, but Chry/Holley did a "bridge kit" to push the air horn back down straight so the air horn gasket would seal. The '72-spec 400 2bbl carb might have a touch leaner calibration, but not a lot. The '73 versions were set-up for EGR and were dubbed 2245 as a result. Use the THICK OEM base gasket, not the thin one which might come with the carb.
Hopefully, the carb kit you got had the thick gasket, too! The replacement Holley I got had one, too. But after a while, I noticed the idle would bet a bit unsteady. I'd get my wrench out and retorque the base plate nuts, about a 1/16th turn. Then the idle got smooth again. After the third time that happened, I got an OEM thick base gasket (with the metal bushings in the holes) and problem solved.
In a prior thread, somebody mentioned that Autoline rebuilders knew about and compensated/fixed the air horn issue on the Holley 2210s. I take their word for that.
Other than the air horn warpage issues and the long-term "accumulation" issues in the venturi tubes, or possibly wear issues in the accel pump well and throttle shaft, just not much to go wrong with those carbs. I presume the choke pull-off is still working?
Just some thoughts,
CBODY67
Jake Fleming
New Member
Thank you! That’s a lot of great info. When I set my timing it was to the prescribed 12.5, and earlier today when I checked it was about -3 so that’s about one spark plugs worth.
I actually have a spare Holley but unfortunately the bolt holes don’t quite line up. It’s an 80s spec for a 318.
You need to be changing that chain before you do real damage. Line up the timing mark at TDC, Have a helper rotate the crank back and forth with a breaker bar and socket on the big bolt for the harmonic balancer. You should have a maximum of about 12 degrees free play before the distributor starts to move. At 15 degrees the chain is out of spec at 20-25 degrees, the chain is at the point of failure. The factory plastic faced gears can go any time from about 70k onward.
Dave
Gerald Morris
Senior Member
He mentioned the vacuum gauge fluttering "quite a bit" early on. I suspect a loose timing chain.
Jake Fleming
New Member
Sounds like we’ve narrowed down to the root of the problem then! I’ll do that little test, and hopefully that’s it! Not too hard a job, I’ve done one on a Ford at least, and the sets are relatively inexpensive for the 383 from what I’ve seen. Thank you guys for the help! I’ll make sure to report back what we find with the crank test
67Monaco
Old Man with a Hat
No I didn't mean with you. Sorry if you think that. There are others around that like to argue just to argue.
moper
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Sounds more like crap in the fuel tank. A timing chain will not "come and go". It will be crappy, and stay that way. When was the ;last time the fuel tank was examined or cleaned out?
Jake Fleming
New Member
Well, some years ago, I can try to look in it with a flashlight. But the fuel flow at the carb is great, there’s no sign of any obstruction or resistance
Jake Fleming
New Member
So I finally checked the distributor relative to the crank, and theres not much free play at all. I took it for a drive, its colder out here now, and it had none of its usual symptoms. So, I think timing is ruled out, that doesn't seem like something engine temp would impact. It seems to me like a vacuum leak somewhere that would be widening as the engine warms (?) or more likely a fuel/air issue. I already rebuilt this carb so i think my next step is going to be to replace the whole thing and see if that cures it. (If anyone was a stromberg WWC they'd like to sell let me know)
The Goose
Senior Member
Hey jake I got a question. How’s the choke ? I had an old 2 bbl and the choke would sometimes go wonky and it would die or run like crap. Before you chuck the carb check and see if it is operating properly. A bad choke is like an on off switch for hard to diagnose carb troubles.
Maybe pop off the arm & zip tie it open. And take it for a short ride see how it does or I’m sure Mr Dave can tell you the correct way to check it. I’m just saying this will eliminate it from you suspects list. Once you eliminate everything on the list you’ll catch your culprit.
Good luck man you’ll get it figured out.
Maybe pop off the arm & zip tie it open. And take it for a short ride see how it does or I’m sure Mr Dave can tell you the correct way to check it. I’m just saying this will eliminate it from you suspects list. Once you eliminate everything on the list you’ll catch your culprit.
Good luck man you’ll get it figured out.
Jake Fleming
New Member
I think I finally got rid of the issue! I did a couple things:
For one, I discovered that the accelerator pump was too tight in it's bore, the spring could not press it down, and therefor I was getting no squirt of gas as I pulled away from stops. I stretched the spring a little to add more tension but that didn't work, I ended up having to sand the leather pump down a little so it could glide more freely. That eliminated 75% of the hesitation and missing. Then I checked the points. They were barely opening, so I opened up the gap some, and cleaned them. I drove it around for about an hour and I'm pretty sure the drivability issues are cured! I did find a carb on Ebay for about $20 though so I think I'm going to order that and use the air horn off of it, I did discover that mine is a little warped in all of this.
For one, I discovered that the accelerator pump was too tight in it's bore, the spring could not press it down, and therefor I was getting no squirt of gas as I pulled away from stops. I stretched the spring a little to add more tension but that didn't work, I ended up having to sand the leather pump down a little so it could glide more freely. That eliminated 75% of the hesitation and missing. Then I checked the points. They were barely opening, so I opened up the gap some, and cleaned them. I drove it around for about an hour and I'm pretty sure the drivability issues are cured! I did find a carb on Ebay for about $20 though so I think I'm going to order that and use the air horn off of it, I did discover that mine is a little warped in all of this.
Jake Fleming
New Member
Well I'm back to thinking it's the timing chain. I had changed out my warped air horn with a good one off a parts carb, dialed in the timing, tuned and adjusted. Points were gapped to spec. All was good, car was running smooth quiet and powerful like it should for a while. Then the other day, ver suddenly it had a bad miss, almost as if the engine shut off for a sec, and now the old symptoms are back. It's gotta be a bad timing chain.
Diagnose for a rich carb is easy: just get someone to observe the car when starting it up. If the engine blows black exhaust smoke, the carb is on the rich side of adjusting.
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