Hi, New to this sight and looking for some advice on the following problem I'm having with my stock F100 69 360 2bb.

Engine is missing at approx. 2k to 3k rpm.
Idles fine and responds well when kicked...for a 360
Cruising at low speeds 30 to 40mph seems to be the worst.

What I have tried: new plugs , points and condensor , rotor cap and wires. Gas is good. Carb was rebuilt about 5 years ago

I have read so many posts with different solutions just looking at maybe where to start .
TIA
Chappy

 

Check your compression. Just a good general health indicator.

 

New points or adjusted timing should be reset. Also when doing a tune-up. A guy should have a vacuum gauge to adjust the carb.

Also Check the dizzy vacuum advance for a vacuum leak, check all rubber vacuum lines for leaks . Is carb choke opening all the way?

A weak coil can cause it to fall on it's face.

Orich

 

Could be a lot of things.

When did you replace the spark plugs?
Does your distributor have points and condenser?
Cap?
Rotor?
Wires?
Coil?
Compression?
It could even be a lean fuel situation.
This could even be caused by a broken vacuum line creating a lean situation.

If you pull the plugs, lay them out like they came out.
Are any of them black and oily?


We need more info to help you.

 

Ditch the points. Points start wearing out the instant they are installed.

Look for a vacuum leak.

Look for erratic timing.

'Could be lean at high RPM. Fatten up the mixture on both barrels equally and take 'er for a spin.

 

2X. Put a timing light on it. Keep your limbs away from the fan and spin the motor up to about that speed. Look at the timing mark. 1st, it should be advanced. 2nd, if the mark is bouncing around it's prolly the timing chain and gears are worn out but could be a worn out Dizzy.

 

One of the overlooked items not mentioned is the fuel pump...with the blended fuels (which almost everybody has), the diaphrams can get pinholes in them over time.....this initially creates a slight miss/or a little lack of performance at high rpms and then progressively gets worse...just as you have described and standard flow/psi test will typically not show this either. Fuel pumps are cheap & easy to replace.

IMHO...

with regards to ignition points.....this is a very good posting regarding Q/A:
https://www.ford-trucks.com/forums/1109528-points.html

and IMHo, there is nothing wrong with a set of points.....they powered NASCAR vehicles through the 70's at speeds of up to 200+ miles per hour!

IMHO, but, what is more reliable than points......certainly not the more popular & common “e-box replacement kits”. Yes you can hear people state "It runs so much smoother/better than when it had points"........in each case that an individual said that in my presence, they had very little knowledge about points and the ones they were running were- old & tired or inexpensive aftermarket replacement units or the individual (including professional mechanic) was unfamiliar with not just setting the gap to OEM specs, but setting the dwell & initial timing to what the engine likes.

But let’s look at the OEM ignition system from the early 60’s….
Original Coil Voltage: 20,000; by the end of the 60’s 40,000 volt high performance coils were common…..by the 70’s 50,000 & 60,000 volt coils were easily available & is what we have today. Did we really gain all sorts of HP/TQ with all this extra voltage…….no, what we were able to gain was stronger support (if you will excuse my terms here) for higher RPM’s- specifically in the 6,000+ range.

In a street application, if you look at the data very closely that is provided by these more common e-box companies, in street applications (where max power-band RPM is around 6000), when the standard dyno deviation is removed (5% standard per every dyno mfg) there is less than 1% improvement in performance. Further testing by independent aftermarket DIS (direct ignition system) manufacturers verifed this through their own testing- there is little gain over an ignition points system until you reach 4000 rpm…then you begin to see a slight sustainment of ignition delivery above what points can deliver but it doesn’t even begin to compare to what a “modern”, real e-based system can & does deliver in a real world street (and race) environment.

I am not promoting this product but their analysis is very demonstrative of actual performance results. link: http://www.compu-tronix.com/MightyMo...risonGraph.pdf
The other item is, in a street vehicle, if you wait to see improvement until 4000+ rpm, the race is over.

Here is a link to a back to back ¼ runs- comparison of points vs a couple of e-box conversions……..no discernible difference PerTronix Track Test

These e-box “conversion kits” have literally the same design limitations as the “conventional points”- because they are essentially using the same delivery system (rotor, cap, wires, etc.) and they are subject to the same inherent design impactors of which there are numerous….including ozone that is produced within the cap…..none of this has by miracle “disappeared” and in fact when compared in true recorded data-frame analysis, the benefit will be gone by 5800 rpm and the loss, although slightly less, parallels that of points. In racing conditions that could very well make a difference, but in a street application, you could literally change brand of fuel and see that level of improvement or degradation. Additionally, there are companies such as ProComp whose “High-Tech Multiple Discharge Ignition Systems” are nothing more than re-boxed low tech conversion parts purchased in bulk from other companies- mostly Chinese-based. Check out this pic procomp ignition box?? of a “new” ProComp e-ignition system- it’s a glued together GM part stuffed into a pretty aluminum box. Considering they were sued in 2006 by MSD (and prohibited as part of a settlement from using/distributing any of their parts), I’m not surprised by anything I see with their crap….but this includes much of the e-box aftermarket industry- a lot of PR documents which physics does not play any part!

Very good quality ignition points/condensors are available and when set properly, are very reliable and provide excellent performance. There have been no less than 5 people who I personally knew were going to get e-boxes, then I had them get a good set of points/condenser, a high voltage (40k+) coil, and installed them showing them specifically how to do it......the engines ran smooth and strong. One person did end up buying an e-box, why, because he said he just got tired of not being "cool", after spending $500 for a distributor, etc (he went “Popular” high end), a year later (when he asked me to help him fix something) he admitted, it was a waste of $...it didn't run any better than after we put the points in.

While many state the positives of e-boxes (and there are certainly many positive attributes), there are conditions which reduce an e-boxes effectiveness & reliability....to start with the circuitry and handling (container vessel shipping) of it from China (which is where 90% of the more common/popular e-box company's products originate). Any aspect including temperature control, static safeguards, moisture can & will cause both detectable and undetectable damage which may not show up until after you have subjected the installed component to real world vibrations, heat, cold, moisture & grease/oil. Yes, all of these damage e-components, but the systems (based upon a variety of factors) are suppose to be prepared to endure these exposures but that is based upon many, many assumptions. Including proper handling & q/a.......given all of the 3rd party involvement in the final product, it is unrealistic (IMHO) to believe that e-boxes have an increased reliability as compared to their mechanical-based counterpart. And in terms of “Dwell Control” I won’t even go into that in detail but I will say, what the “kits” provide is a joke…..you can actually get more control over the dwell by having an understanding of how to set timing versus dwell setting with points than the most popular e-box conversion kits can provide (which can be verified on any test bed)…..which makes for a very smooth running engine- this is not just IMHO, but well known among the "higher quality" aftermarket engineers whose systems reflect this ability to "tune"!
If you need to say I got rid of my points…ok, that’s fine, but if you are really serious about actually upgrading the ignition system then do so……although it has been scrapped by the OEM’s in favor of more advanced, effective systems, there are aftermarket DIS units (yes the same as Ford used in the 90’s & developed by Porsche in the 80’s) whose cost is within reach of most buyers and will actually perform as stated.


Ok, I'll get off my box now (:

 

Someone hit on this but didn't go very far. Fuel lines, if the are old and cracked, you could be sucking air in the fuel line. The crap we have for gas, if you have fuel lines 5 years old, change em.
Don't throw parts at it hoping it will stick, start with the least expensive solutions first.
Timing lite to set you base line and vacuum gauge for fine tune.

 

thanks ill try that 1st

 

Tune up just completed witch included fuel filter, coil, plugs , wires, points condenser. Not the cheapest stuff on the shelf
I have no problem with points! cheap and easily replaced.
Fuel pump was replaced when carb was rebuilt 2011 ish.
Checked for vacuum leaks, fuel line from pump fine.
timing checked at local garage, he thinks possibly distributor? I see little to no play in shaft and the advance plate seems to be moving freely

Like I said... this thing has always run A1 since taken out of storage 2011.

Not sure if this helps but ...when all this started I had just gotten off the hyway from a little run 60-70 mph. Idled fine but misses like crazy around 30mph.

Same thing standing still. Idles fine , as soon as I bring up the rpm's starts missing,take it up a bit hire smoothens out again

 

Re check points and make sure vacuum advance is in proper working order.

 

When you pulled those plugs did they look like the engine is running lean? Did the fuel filter look plugged up? Problem could be junk in the carb. Somewhere right around where your problem lies is where the carb has switched from the idle circuit to the cruise circuit. And the idle circuit has totally fallen off. The carb goes from idle , to a mixture of both circuits, then totally cruise circuit. So it is possible somewhere in the cruise circuit passages they are plugged up. When you REV higher than the problem the carb is prolly jumping in to it's Power circuit. One thing you can do real easy is make sure the venture cluster air bleeds are open. Look down the throat of the carb and you'll see the venture cluster. I found the pic below by Googling. It shows some wire in the air bleed holes.

 

Note that the air spreader will obscure these ports from view.

 

Thanks for all your replies,
Started with a couple simple things that were suggested to start off with and found something quite interesting!
after re adjusting the points I fired her up and found I had same missing problem so decided to check vacuum line to carb and this is when things got interesting.

When the vacuum line was disconnected at the distributer it ran smooth as silk at all rpms???

As soon as I reconnected it went back to same missing problem??

I'm no mechanic but this is messed?

 

Check the diaphragm on the Vac advance. It is probably leaking.