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A few people have asked what can be done to fix the cold stuble and off idle stutter common to 85 hp Fox 3.3 sixes.
Most people have hot starting issues, and there is a lack of info on these carbs.
The problem in hot areas is much like a car having hot fuel handling problems. Although not THE primary solution, such a set up works as a band aid repair. Ford and GM did it when they decided not to do underhood shielding and other changes that Ford used with the 5.0 V8 HO carb cars from 1982 to 1985, cars that had 8.5 psi of fuel pressure possiable at the carb.
Most people who work there cars,
like to strip off the factory parts, and with headers, open air cleaners, and no fan shroad and air snorkles, you'll need fuel line blead back.
Its like this car.
https://www.youtube.com/watch?v=YUmaAQoHggM
The problem wasn't really fuel pressure, but what was done to the shrouding and the exhaust and carb. If factory Fox or F150 style shrouding and air cleaners were used, he'd not have needed any fuel pressure bleedoff.
Ford Australia first had this problem during the Aussie Draughts in the early 80's, and the solution on the 1982 to 1992 in line sixes was to have a
blead back return line to the fuel tank.
The Carter fuel pump got revised like this below. Again, if Ford Australia had used some of the US style hoses, shrouding, and sperpentine drives, they could have kept the fuel pressure up like the 8.5 psi the 1982 to 1985 carb 5.0 Mustangs used, and just used the priority carb bowel vent, but they instead used the European Fiat carb. Go figure!
That is perhaps the easiest solution to one aspect of your problem. Its certainly not stock solution for your years Ford Mustang though.
On GM Holden 173, 202 sixes, and the 253 and 308 v8 engines, they used the same vapour line as the 1981 to 1985 VV7200 carbed Panther Platform cars like the LTDS, Crown Victoias, Grand Marquis etc. They had a device which blead back vapor pressure to the fuel tank. When there is too much vapor pressure, the needle and seat locks off and stops the car running right.
Fuel pressure control and vapor control aren't exactly the same, and adding a set up like the ones above might help, but there are other ways to fix the stutter and idle issues.
The issues and manner in which the stock 4.2, 5.0 AND 5.8 Panthers with the VV7200 carb did there job was discussed in post #8
http://vb.foureyedpride.com/showthread.php?175328-Will-Magnaflow-Cats-fit-on-my-Long-tube-H-Pipe
Anyway, the other issues that will be causing the actual problem.
9 times out of 10, its this part,
1.
The intake manifold adaptor and its
Vehicle Emissions Control Information=VECI, which governs
Vacum, Emissions, Carb, and Ignition line settings
The aluminum intake adaptor that links the carb to the iron head. On your 79, it has a problematic adaptor dating from 1974 that doubles as an EGR post, so it suffers hot and cold leaks, and sometimes has cracks that hurt the idle. The EGR function is tied in with the VECI diagram, and its important that any diodes to and from the AIR, EGR, and the Choke are correctly attached. Just having an MCA judged car doesn't mean the parts are correctly arrayed. There are about 70 emission control features on the 79. Any one of them can be the problem.
Do ensure you snub the carb and carb adapter up evenly with a small torque wrench i9f you can, there is only two bolts 180 degrees to each other, and the whole 1-bbl carb wobbles like a b stard after a few years of service.
Same with the 240/300/4.9 big six truck engines, a leaking carb base is such a common problem, and its sometimes hard to track, and even harder to take the hour or so to snub it down properly. You can do it with hand tools like a cranked open ended spanner, but unless the gaskets are right, its easy to unequally load one bolt, and get a leak.
The recommended torque settings are here
http://classicinlines.com/SmallSixSpecs.asp#TorqueSpecs
Intake = 16-18 lb-ft
Some 1-bbls on 144-170-200-250 and 240-300's have four bolts with two bolts down low, two up high, the two clocked at a weird angle. Leaks are so common.
2.
Ignition Settings and Components, namley "Advance Curve issues and non spefication parts (like ignition caps) that were sold that were out of factory spec in there plastic mouldings and spring tensions.
Vac advance systems that are worn out, or aftermarket distributor caps that don't even have the six leads indexed the way that Ford intended. Although all Ford I6's are the worlds most simple sixes ever, they sure do have a bunch of really simple things that can be wrong that make 'em hard to tune.
3.
Electrical Earthing
a) I'd look at the engine block earth to the engine first, make sure there is chassis to block continuty, and set up a second earth strap somewhere on the cylinder head. I'd ensure the Duraspark II has clean contact points and wire continuity. They are getting old, and wires that look and test as being items with continuity, aren't always fully functioning.
b) I'd put the ignition advance and whole distributor on a Sun analyser to see that its in spec. I have two US contacts who I trust after many years of co work with the Ford Six Performance forum.
c) The ignition switch needs to be checked.
d) The battery may be shorting through its 9 plates...that can create non starting cars when hot.
4.
Mechanical Blueprint settings for timing, preload, backpressure, fuel supply volume and pressure variations
I'd recheck
a) the hydraulic lifter settings with a proper lifter setting tool that bottoms out the lifters, and then re-set the lifter preload clearances to spec.
b) I'd then test the backpressure in the exhaust. The catalyst could simply be creating excess back pressure. More than 6 spi is too much at wid open throttle/4500 rpm.
c) I'd renew the fuel pump, and then check the positioning of it to maximse peak pressure to 5 to 6 psi and total out put for 85 bhp net. Just preositioning the fuel pump on its bolts can change the stroke of the fuel pump, and fatten its fuel delivery pressure and out put.
d) The other thing is harmonic dampener slip. The stock 9 Degrees Before Top Dead Center of whatever won't be as indicated by a timing light after a few years of dampener rubber ageing. The timing slips when rest to spec.
In a similar way, within just six months of operation, the stock single row timing chain suffers a huge amount of spark scatter and cam duration change from acceleration to cruise. In terms of engine idle stability, the stock ignition timing is then out of whack, and it scatters under load and over run. A Mustang uses the same kind of timing chain dimensions as a twin row timing chain on an A series Healy Bug Eye Sprite, and it was used to tighten up idle quaity and timing. It got retrofitted to the late sixties Australian Ford Falcons to help improve safety under load (the cam can hit the con rods when the engines timing chain stretches with old age, but it always a good policy to upgrade it)
Second lastly
5.
Its the Ultimate Econo Engine!
http://www.mustangandfords.com/how-...-to-improve-six-cylinder-mustang-performance/
Some passing notes on the last thing to do.
6.
Rebuiding the Carb.
The choke set up for 1979 chaged in the early 80's to the 25 psi of vac applied to the choke unloader. I'm not sure on what the 1979 spec is, but it has the EGR port proble, no control purge cycle for the car vent tube, and the adjustment for fuel enrchiment under throttle is by just bending the accerator pump wire.
The 1946 Holley is just an advanced Autolite 1101, or Holley 1940, Holley 1945 (also branded as the Autolite or Motorcraft). Its similar to the Chrysler 1945 carb.
Bending is the method for adding pump stroke to the accerator pump. On the old carbs from 1961 to 1969, it was via a triangular plate with sloted holes.
The last thing I would do, after all esle, is rebuild the carb.
Due to the problems with modern fuel, your best bet is to contact Will Ambler (
was111) or Farron Rhoads "
FordSedan Delivery", and have a second exchanged distributor recurved away from factory stock to remove the dead spot. A Duraspark II will cope with a huge amout of intial advance, and a greatly reduced total advance with a more aggressive spark advance growth.
All these 6 things above things were changed by the Australians when the 1976- 1991 3.3/4.1 Cross flow, and the Americans six cylinder Falcon six derived HSC 2.3 and 2.5 came out in the Tempo/Topaz/Tracer and Tauruses between 1984 and 1986. They were not fixed on the US 3.3 because they were the worlds cheapest to build six cylinder engine.
Hope this helped some.
Carb is the last on the list, but the rebulding of it is simple. Internally, the Holley 1940, 1945, 1946 Brass Float is the same.
The problem is that the 1940, 1945, and 1946 Holley's aren't the same carb externally, but readically different externally due to the choke position changes, and the vent tube changes. For a simple 1-bbl, its very prone to finding vac leaks, and having the check balls the wrong size, weight, or the specifications messed up.
To rebuld the 1946, you have to follow the Mikes Carbs Holley 1940 rebuild, and then the 1945 Mopar Holley version, and then, lastly, work out what is different with the 1946.
The 1946 kit.
https://www.youtube.com/watch?v=7ALbDtnxvRo
The 1940 kit
https://www.youtube.com/watch?v=ra_pAzqRNlc
The foundational 1940 Holley rebuld videos
https://www.youtube.com/watch?v=CzHc0BKexlI
https://www.youtube.com/watch?v=ht18I7djTZM
The foundational Mopar 198/225 1945 Holley carb video
https://www.youtube.com/watch?v=gBti9Y-5g60
See
http://vb.foureyedpride.com/showthread.php?171649-1981-Ford-Granada-GL-3-3L-i6-help
They act as heat sinks.Many moons ago a friend has those problems.tried the wooden ones.No joy.Robbed 6 of his Moms aluminum ones off the clothes line.Worked like a champ.
