Motor timing 180* out?

[Turbogus]

The power valve (accelerator pump on AFB's) I thought were only activated by pumping the throttle on the Holleys. The accelertor pump relies only on the lever action of the throttle arm going beyond idle from what I can see on this AFB (Sorry no pic yet) the trow of which was maladjusted by me prior to this last needle/seat change, it's since been corrected.

 

[Turbogus]

Reinstalled the AFB with that small seat and the motor fired right up after fuel reached the carb, I'm hoping now I'm on the right track. Did I turn this 360 into a turn key?

 

[Torxhead]

Gus, since you are playing around with the fuel mixture by changing the seat dia., it would probably be a good idea to keep and eye on the spark plug burn colors.

 

[Hedgehog]

But, the float needle valve is just that, a valve that controls the in flow of fuel into the float bowl. Other than overflowing, it has nothing to do with the way the engine runs. That is controlled by the jets. It sounds like he has finally matched the proper needle and seat. Now when his carb. needs fuel it has it, when it doesn't the fuel flow is properly shut off. I suppose if his engine is finally running correctly it would be a good time to put some miles on it, then check the plugs. Even that seemingly simple task isn't as easy as you'd think, there are some tricks to doing it correctly.

 

[Turbogus]

Got the motor running last night and I was intending on finalizing the mixture and setting the timing but the motor slowly chugged to a stop after startup. Thereafter I could get the motor running again (slightly less rough) by keeping the revs up around 2000. This is when I noticed fuel puddling on the intake maniford again. I guess I'm not out of the woods with the leaking throttle shafts, unless that fuel is due to sitting out of the carburator, but I doubt it. Unfortunately my finances prohibit buying a new carburator which is why I keep delving into this one.
Going to pull the plugs tonight as I'm sure they're fuel fouled since the last time I went into this AFB.

 

[Torxhead]

Gus, you might want to check for cracks in the throttle body. I wonder if the needle and seat is able to close all the way also.

 

[Hedgehog]

I do wish I could help you, but it seems that your carb. problems are not your ordinary carb. problems. With all you say you've done, this should have been taken care of long ago. Good luck.......................

 

[Turbogus]

I'm going to take a closer look at the Viton rubber tip of the needle with a lens, to the naked eye it looked free from damage but with this persisting problem I must be missing something.

 

[Turbogus]

....it's getting closer, before the change of the seat (needle & seat) to the smaller size it wouldn't run at all.

 

[Turbogus]

Looks like I'm having to pull that AFB again and take another look at those needles and re-check the jet, rod and springs, although this carb was running great without any changes to them for the last 3 years. The enlarged photos I've posted here though of the needles don't seem to show any damage to the spring type (black tip) that is installed now, although I do see a ridge on the red tipped needle.

 

[Hedgehog]

I absolutely have to ask this question. Do you know how to adjust the float height? You can't just drop a float/needle/needle seat in a carb without adjusting it.

 

[Turbogus]

Not being able to be present to actually visualize the steps I've taken and the work I've done I can certainly understand your question Hedgehog, no sweat.
Having rebuilt a couple of Edelbrock clone carbs and having gone into this one a couple of times I've adheared to the specifications contained in the instructions and since having been turned on to the original installation sheet from when I bought this AFB new in '85 and that SA book by Dae Emmanuel I'm clear on the procedure and spec.

Inverted float setting 9/32 inch and float drop 15/16 inch (or by the gauge 30/32).

I think when I go into this again on saturday, I'll much more carefully blast the carb throttle body and air horn (disassembled) with carb cleaner in a more dedication fashion. The first go was to use carb dip and then CRC carb cleaner so I'm hopeful that there some buildup in an air passage somewhere that this'll address.

 

[Neuner]

I do wish I could help you, but it seems that your carb. problems are not your ordinary carb. problems. With all you say you've done, this should have been taken care of long ago. Good luck.......................

Yes, I agree.

Going back a page or two about your fuel pump, would just like to throw in my experience. I had an electric fuel pump straight to a non-regulated fuel filter which then went to the carb. Not sure of the pump output but I put on a fuel filter which regulated it to 5 psi and like you, I had no change. Following others direction, I then went back to my original setup but instead installed a Holley 0-4psi fuel pressure regulator between the pump and filter and set it to 3.5psi as directed. Made a significant difference. Ran much much better. Mine was a AMC 258 i6 / 4.2l with a Weber 32/36 but I've read about the same pressure requirement on quite a few other vehicle and engine types.

 

[Turbogus]

I can dig that Neuner, this motor still has the mechanical fuel pump from when I bought 'BB' around 5 years ago. I doubt that by any means this pump would increase its pressure over time

After my best friends reccomendation (same guy that sold me back this AFB 3 or 4 years ago) I introduced a Holley FPR between the filter and the fuel inlet of the carb. This was during the time the motor would not fire but for a few moments, patiently with each attempt at restart I moved the dial incrementally from 5 down to 1 and back again but it seemed to make no difference.

Pulling the no. 1 spark plug thursday, it was coated with fuel soot.

I've got some freight to delivery today so it may be until Sunday before I can get back to this AFB.

 

[Turbogus]

Okay the Primary jets were No. 395's .095 inches and the Secomdaries (that I installed when earlier I found no jets in the secondaries at all) were No 398's .098 inches. In the Strip Kit I have other Jets that as I can detirmine are;

401 - .101
400 - .100
396 - .096
395 - .095
392 - .092

I reckon I could start with the next lowest with a new plug in No. 1 and see how the land lays and move down from there.

 

[Turbogus]

In addition to these jets I have a selection of rods, but I can't seem to find online the sizes corresponding to the numbers stamped on these rods, does anyone know the coding on these?

Originally on this AFB 16-7147
xx47
18-7037
7342
7347
16-W8500

 

[Hedgehog]

No doubt about it engines don't run well with no jets in the secondary's, especially when the distributor seems to spontaneously jump 180* out .... then there are those pesky rods and uncoordinated numbers ..... with all that I bet the fuel flowing out from somewhere in large enough quantities to pool on a hot engine plays havoc with fuel mileage.....................

 

[Turbogus]

In hindsight I don't think the distributor was 180 out in the first place, just a misnomer from another thread.
I'm starting a blog at Mike's Carburator Parts in the hopes for a definitive chart of some kind that can help me decypher these rods.
I have learned that the jets drastically change the fuel, while the rods finesse or 'dial in' changes. I just don't want to blindly go into this again and fuel foul another set of plugs, (done that twice already) especially when it's such a pain to get to plug nos. 6 & 8

 

[Turbogus]

I just purchased new digital calipers yesterday, sure made exacting work of the float and drop, one of which using the gauge from the rebuild kit I was off 1/16" I hope to mic out the rods and find the most restrictive and try 'em out.

 

[Dolamite]

Your engine will be in the seemingly perfect spot twice, once when the valves are closed and ready to fire and once where the exhaust valve is open for purging exhaust. This is an easy mistake and you see it on the car building shows all the time. I mentioned one way to reset your dist. the other is to turn the engine over by hand until the timing mark is lined up again. Then reset up your distributor. If you/we are wrong in the dist. being 180* out no harm done, just reset back the way it was. Here's an odd thing. some engines will run, run horribly, but they will run with the dist. 180* out. Exactly how I don't know, but it's been talked about right here on this site.

I just stumbled upon this thread and it piqued my interest. After I put my rebuilt AMC 258 i6 / 4.2l in, I went to time it and the timing mark on the balancer was 180 degrees off. The engine runs fine without any backfiring, so I left it alone and have been driving it that way for a good year or so. Is it possible that an engine can run fine with the timing 180 degrees off? Would it cause any damage? I believe my rotor is pointed toward the #1 plug wire, but I'll have to double check.