Carb vs Fuel Injection

Norman

New member
Rebuilt a 66 Mustang 200 6cyl with 250 head and built to Clifford specs with a weber progressive carb
but have not been able to make it idle right. Thinking about going to fuel injection any pros or cons and
what brand. Or what carb would be best.

Thanks For Any Help
 
I'm going to fuel injection for the same reason. Even if you dial it in, the weather changes, shiz clogs up, etc. If you have an automatic and a cam you could have a stall issue. But carb's just don't atomize like injectors unless it's in the sweet spot imo. And when you're working with 40 year old gear it's crap shoot, who knows where that carbs been or what it was like new. Friday at the factory we used to say, or Bob Marley's birthday. I was hoping to do the swap this winter, but I'd like to get the body right and paint. I'm considering trying one of those chinese YFA repop's. I figure if it's a pos I'm only out $100 and at least it's new. My RBS does great with any throttle, but loves to miss at idle if the stars aren't in the right alignment. And it will idle as low as you want and not die, but the idle quality still sucks a lot of the time. You can get it as good as it gets, which is close but not 'there', and next week low pressure, whatever. It's ok for daily driving, but it could be way better. I want it to purr like a kitten at idle, in gear and launch like a mofo to
 
What about your transmission? 3.03 4 speed, T5 or C4? What's the lobe separation on the cam?
 
Dont want sound dumb wwhat is RBS.
The weber I have runs great at mid to high end but idle I hae to turn
in idle screw in so far to get any rpms it loads up when engine is shut off
or drains carb down engine.

Norman
 
Norman":18gpk2f4 said:
Rebuilt a 66 Mustang 200 6cyl with 250 head and built to Clifford specs with a weber progressive carb
but have not been able to make it idle right. Thinking about going to fuel injection any pros or cons and
what brand. Or what carb would be best.

Thanks For Any Help


Its all

1. Fuel delivery system hygene and maintenance (pipe degreatation, precipitate formation, non ethanol reistant rubber degredation)

2. Ignition

3. Postive Crank Case Ventilation valve and

4. Weber spec float level and

5. idle air bleed and

6. fuel pressure related for 2-bbl Webers.


Adding EFi won't solve the problems that can be easily solved with the correct Weber 2-bbl set up.

The Best 2--bbl carb in my opinion is

1. the Autolite 2100 and Motorcraft 2150 for operation,

2. the Holley 2300 7448 and 4412 series for space utilisation,

3. the Weber 2-bbl 32/36 DGAS/ 38 DGEV for parts back-up and information.

Regards ignitions, well, the aftermarket supplies Ignitions for a sharp price, but the increasing "Gray Haired" Gurus like Bill Ambler Race ( wsa111) and FalconSedanDelivery who retune those things to suit modern fuel and modern carb calibration with the right kind of vacuum source to eliminate idle problems and create snappy, well torqued responses on a 6 cylinder multiple barrel car.

Nothing Ford stock (even Duraspark 1, or 11) works flawlessly out of the wreckers yard.

You HAVE to get your ignition recurved to suit your planned engine tuning end point. Period.

Regards PCV. The line to the carb has to be baffled, or at the very least, given a length of pipe to create a pressure standoff. The float bowl level gets hammered with the PCV valve and often people do danged stuppid, non standard stuff with the 2-BBL Weber float bowl vent. AE Wagners make a balanced PCV is a low flow copy of the Ford PCV that Mustang_Geezer found worked so well to stop oil and crank case ventilation hurting the float bowl level in his Carter YFA and then Holley 2300 "7448" carb...lot of really good work done by him on this forum back in 2001. FrenchTown Flyer suggested it again with everyone who had problems tuning their 2100/2150 Ford carbs. AMC guys found out all about this issue back in the late 60's and early 70's with YFA equiped 1-bbls...never idled right if they had the wrong PCV. 90% of idle problems are based on manifold vac source and the wrong PCV routing.

For Weber float level, there are three or four specs depending on carb number, the US forum Jeep and AMC, and MG boys found the right info on that back in the 00's.

Idle air bleeds, the Weber is a bit of a disaster. The same with fuel pressure, which has to be limited. Periodic clean, good componests, great results.

You don't want to be running an EFi system unless it has a specfically designed fuel tank stillage pot, or it'll create untold other problems.

EFi requires Specfic Engineering. Its the old dog with the bone thing. Anything extra than you already have...lookes better. Its not the case. Some people have it easy with EFi swaps, that's because "they" get lucky with not ever running them down to the last oz of gas, and "they" don't test the handiwork like Ford had to to cover fuel delivery fires in a tail end shunt like Ford had to. I favour EFi, but only if done to better than as new 1980 to date Ford EFi standards of engineering. We now have ethonal gas and oxygenated blends, and then you have a EFi Old Car without the Ford Motor Company Fail Safe Devices.

We don't know more than the Ford Motor Company. Ford over seas (Europe, England and then Australian) made 2-bbl Weber carburation work, but only after very serious under bonnet fires in Mark IV Zephyrs and Cortinas and Taunas cars.

IMHO, if Europe, England and then Australia were the US, the Weber Under hood fires would have forced corporate lawyers into bankrupcy court before civil cases, and that situation forced a whole raft of changes to make the overseas Weber 2-bbls safe, and operate cleanly. Ford USA totally re-engineered its Holley Weber version of the Weber 32/26 carbs to cover off fuel fires, and fuel pressure and PCV valves were specifically changed to suit the application. Then the Pinto Fuel tank came and bit them on the a$$. Ford really did an heck of a lot of work to fix that kind of stuff up from 1967 to 1971, and utlimatley, because it did make every step practicable, it made the grade.

Don't think EFi will help you avoid other problems. Form my personal experience. EFi creates other problems that you then have to deal with responsibly, and that requires an extra dose of fail safe devices.

My back ground is propane and I have friends in the fire and emergency services, and I hear the horror stories.
 
X, when I do my swap to TBI I'm going to install one of those EFI 22 gallon Mustang tanks in the van with the right pump from tanks inc., VSS in the aod speedo output and a signal converter, GM knock sensor, GM computer, GM external 8 pin module, DSII dist, custom chip, ect.

Make sure you don't have a vacuum leak, like at the trans, brake booster etc. The RBS is a 1bbl carb made by Carter. Webers can be complicated to setup right from what I gather, but are great carbs once dialed in. X is the weber guru around here, listen to his advise or do a search on the forum.
 
Norman":2siva65m said:
Rebuilt a 66 Mustang 200 6cyl with 250 head and built to Clifford specs with a weber progressive carb
but have not been able to make it idle right. Thinking about going to fuel injection any pros or cons and
what brand. Or what carb would be best. Thanks For Any Help
it may take a little tweaking to optimize the Weber carb's drivability. Any other carb available to install/compare may be helpful for a rough idle comparison to check other engine basics. What kind of Vac gauge reading?. Depending which progressive Weber (32/36?} , which jets and emulsion tubes determine idle and accel' response.

I run a Capri 2800 H/W 5200 Weber clone carb on a 170 Falcon with consistent idle and smooth response for @15 yrs. I had tried other 5200;s with good idle but stumble at accel' until the Capri app' 5200 . Something about different emulsion tubes made the difference i think/

hav efun
 
as usual X gives a lot of good information. study it carefully before jumping into a change over from carb to EFI. it isnt the basic hardware, or even the software that is the problem, its all the little details along with making sure you use the proper fuel line, fuel pump, fuel pump location, etc.

and dont forget the return line, among the myriad of other details that will trip you up along the way.

if you do decide to convert to EFI, start by reading up on this board in the EFi forum, and then hit the megasquirt forum as well. and check out https://www.diyautotune.com/ as they have the products you need to get started along with a lot of good information from people who have done the conversions on a variety of vehicles.

lots of good information out there, so study up and plan well.
 
Your problem is IMHO, just the distributor and porting advance. If your needle and seat is not working, then its a waste of time tuning a Weber for a carb that has a fault.


EFi is ultimately much more simple to control than a 2-bbl carb, and the MSII system is much easier to trouble shoot than an EECIV or EECV EFI but it really does require networking with really good support. The community of EECIV Qaurt Horse and MSII users will help you, and its something fun, aspirational, and essentially good and simple.

All my current cars and my sons cars are EFi.

Cars? 24 in the last 32 years since starting driving as 15 year old
'58 Vauxhall Velox, 68 hp SAE net , 6.8:1 c/r, 4 spd, 3.45:1 axle, 21 Imp mpg
'76 Ford Escort 45cwt Van, 1.3 HC Kent, 28 Imp mpg, 4.44 axle
'75 TD Ford Cortina 2.0/C3 auto, 3.75:1 axle, 24 Imp mpg
'77 Morris Marina HL 1800/BW 35 auto, 3.9:1 axle, 21 Imp mpg city
'74 Mini Clubman 1100, 3.44:1 axle, 35 IMP mpg hwy
'74 Min Clubman 1000 (Vizard project)
'74 Mini 850 (Vizard project)
'69 Morris 1100 Twin Carb with Cooper cylinder head (Vizard project)
'82 Mitsubishi Sigma RWD 2.0 Sirius, 5spd, 3.44, 40 Imp mpg hwy
'84 Ford Falcon 131 HP 4.1 BW35, Impco LPgas 2.77:1 axle 22 imp mpg hwy
'88 Toyota Corolla 1.6 GL 96 hp AE92, 22.3° 4AFC Twin Cam, 42 imp mpg hwy
'76 TE Cortina 2.0/C3/3.75:1 DIFF parts car
'82 TF Cortina Cologne V6 2.3 114 LPG/IHI Turbo C3/C4, 3.45 Atlas
'78 XC Falcon 500 96 hp JIS net LD28 diesel, 3.23:1 axle
'80 XD Ford Falcon 4.1 126 DIN net hp S pac Panel Van, 2.92:1 axle, 4.1 3spd
'87 XE Ford Fairmont 4.1 164 DIN net hp EFI Station Wagon, 2.77:1, BW40
'80 TE Ford Cortina Station Wagon 2.0/4spd 3.70:1 Aussie
'95 RAV 4.1 J spec with G spec 170 PS engine Green 16.2/28.2/22.2 US MPG
'95 RAV 4.1 J spec with G spec 170 PS engine Red 16.2/28.2/22.2 US MPG
'98 Ford Explorer XLT 4.0 SOHC 5 spd auto, 3.73:1 15.2/22.6/18.9 US MPG
'81 JDM Ford Mustang 3.3 L/GL Hatch, C3, 2.73:1 10.3/17.0/13.7 US MPG
'96 WC34 AWD Nissan Stagea 2.5 DOHC Vtec, 4.88:1 20/28/ 23.3 US MPG
'92 AE92 1.295 Liter Toyota Corolla 5 door hatch with 3 valve per cylinder Carbed engine.

Plus service attendent for my sons last four vehicles 1984, 88, 89 93 FWD Toyotas and 92 Mitsubishi Galant 4G32
Currant vehcile is my dads ancient 1984 Speed Density ST165 TBi 1.832 liter Toyota Corona SOHC with 4 speed Auto Overdive. Given to my son, and its on 120000 miles, only had the fuel pump and ignition done, plus a Air Fuel mixture ratio change, a base timing bump up, and it does 32 US MPG.

So I've had the EFi thing and the carb thing, and the 250 thing, but I loved the carbed 200 BEST.

If all the fuel pressure, float level and idle jet circuits and needle and seat circuits, brake booster, PCV and electric choke circuits are factory spec, then you'll still have air cleaner cold operation matters.


The full solution is to wind up the static advance to 9 to 16 btdc, and control peak adavance to 32 degrees total, should be all in by 2800 rpm. Your choice of manifold or ported vacuum. I favour the Spark Advance port system Ford Australia used. But you can't sart on that untill you've got a factory 1973 US emissions spec air cleaner system, electronic ignition with the Mean Best timing advance curve and dual diaphram, and a way of practicing some IMCO style spark amplification. The way Ford USA does it is best, but not everyone aggrees, and thats okay.


I can't post the stuff I'd like to because the Paul from FordForums Photobucket album is private, and the pictures have dropped off the acess portal, but the 1982-1985 Ford 200 AND 250's with 2-bbl carbs basically copied the ages old US 167-1973 IMCO system which Stormin'Norman and Frankenstang and I dicussed. Its essentially an integrated 1967 to 1973 system, which is a 13 element strong system, which has colored schematics for the 1982 to 1985 Fords. Aussie Fords don't have the Thermactor system, so thats where you drop another 18 parts on the full blown 31 part IMCO/Thermactor system.

I have had over the past 13 years, starting in 2004, nothing but total resitance to emission control, and was pretty much done with rehasing the basics. People are close minded to it, thinking Dracionan State, Authoritarin Over Lording emissions parts on the Ford parts books since the 70's will screw up a great aftermarket carb.

By the USA 1981 to 1987 Carb emissions package, it got to about 85 items strong; its even harder to fathom. Took me five years to get a handle on it.

People with carbs don't understand the implications of extream rich or lean jetting, and trying to prop it up with float level.

Your car will run fine on 16.1:1 air fuel ratio, and 12.5:1 on the power valve under acceleration. It'll idle just fine at 14.7- 15.1:1 if you have the spark advance controlled right.

The ends justify the means. The result should be a lot of base timing, with a sharp decline in advance past 2800 rpm. The cold stumble can be fixed by using the very aggressive method of amping up spark advance to warm up the engine, then pull it out by Spark Delay valve.

No-body seams to understand that Ford spend billions meeting the USA emissions regs, and found that most of the compliance issues were taken care of by a Duraspark electronic ignition, with a very aggressive spark advance cold to warm the engine, then a pullout of advance by spark delay. The water and manifold TVS switches provide the cross over point. Webers are pretty poor atomisers of fuel, 2100 Autolites and 2150 Motorcraft 2-bbls are better, cleaner carbs, and the Holley 2300 series 7748 and 4412, just as good if set up. The solution to getting a Weber 2-bbl to work cold is to keep the US 1973 Emissions parts the 2-bbl Weber carbed engines were forced to run. Our Aussie Falcons from 1982 to 1985 had to meet US 1973 emissions, so they had the cold start delay valves and two TVS ports from the water thermostant, and another from the manifold to control spark source. In 1986-1992 2-bbl Weber Falcons, they met US 1975 emissions, and had another kind of schematic.

Success is when you can cold start your car at 7100 feet, go and have a cup of coffee, and come back with it still running, and give its choke pulloff engergized and the engine idling at 850 rpm.+/- 50 rpm. That's what the Air clean Cold weather modulator and TVS valves do. That kind of emissions crud stops you having extream lean condition, compromised tuning. The fact that the idle screws have to be so far out means you have a porting and igntion set up issue. Fix that by an Air Cleaner with proper heat stove off the exhaust header, a proper TVS to control the wide open throttle cut out of the flapper, and then the upper radiator neck has to have a TVS to control a high advance to the distributor untill the water temperature heats up, then the Spark Delay vlave kicks in. At the same time, a 7 volt electric choke pull off must be set up to kick in at 17 "Hg using a hand pump, that that takes care of the cold start advance sequence. This was how Ford did it on both England, Australia and the USA emissions carb 2-bbl Webers.


I'm okay with other people declaring love for no emission junk/gunk, but Webers need idle stop soleniods, A/C Thottle modulators or "kickers", and Delay valves, ACW Modulators, a leak free modulator if automatic, and non malfunctiong brake booster, and a way of pulling out timing when warm.

I like vapour canisters and purge valves and they all go togeter to make a gasolne carb vehicle function the way Ford intended it to.

My 81 Stang 200 was 100% better than any other car I've owned for cold starts and hot fuel handling, better than my 1984 Aussie Falcon 250.


Then make sure the bowl vent is not hooked up to the PCV circuit.
 
Thank You for all the info lots to think about.
My cam is a 264 duration 444 lift.


would like to stay with the 38 weber because it is paid for.
I have done about everything possible to get this to run right at idle.
Ive got a mallory dist set for this engine I have sent the carb back to redline
three times the last time with drilled butter flies. I found a crack in the head and
replaced it with a 250 head.I have degree wheeled the cam put in new fuel lines.
No pvc hooked up 12 inch of vacuam and still will not get any idle rpm with out turning
idle screw in beyond weber specs. And then when you stop engine after running the carb
runs the fuel back down the engine .At witts end want to make carb a boat anchor.


Thank you all for all the help Norman
 
Have you checked your fuel pressure yet? Webers don't like excessive fuel pressure so you may need to install a fuel pressure regulator or a fuel return line to get it to work. Good luck :nod:
 
If I'm reading you correctly, the fuel drains out of the carb into the intake manifold after the engine stops running.
Can you tell where the fuel is running out from?
 
Yes when I shut the engine down from running when engine is hot
you can look down the carb and it is dripping out of the bleed holes
near the butterfly. Weber says this will happen if I have the idle screw
to far in. Weber says max 3/4 turn in mine 1 1/2 2 turns to get 800 rpm.

Thanks Norman
 
According to Weber, if the mixture screw is too far in to get a proper idle, then you need to go down on the primary idle jet size.
The float and fuel level need to be correct first.

Remove the top being careful not to lose the clip for the choke linkage.
With the top almost vertical so the floats are not depressing the spring, the floats should look parallel with the base of the top.
The actual distance from the base to the top of the float is either 35mm or 38.5mm
Hoping your carb documentation has that spec.

If the fuel level is OK there should never be a time where fuel leaks out of the carb.

The idle mixture screw adjustment is only valid if the throttle plate is almost closed.
The hole in the plate should allow a more closed position for idle.
 
The float is set right or at least weber says it is they have had the carb
back twice and say everything is right. I have changed primary jets ,secondary jets main jet
air corrector with little change fuel still still drips out progession holes.

Thanks Norman
 
At this point of frustration I would set the carb on a bench, remove the top and fill the float bowl with gas a little at a time until I saw gas leaking out the holes.
If there are no leaks until the fuel get near the top then I would do the following.
I have been known to drill a hole near the bottom of the float bowl so I could install a small nipple for a clear plastic tube that runs up the side of the carb to check the fuel level while the engine is running.
 
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