Vialle Type F

Propane, Butane, LPG, GPL, C3H8, C4H10
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Retroracer
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Vialle Type F

Post by Retroracer » Fri Jun 13, 2014 5:24 pm

I'm a forum newb with a '71 F250 and 390 on LPG/gasoline. I have a feeling this has been asked before but after searching 70-odd posts here - plus another 2 hours on Google - I couldn't find my answer. I want to perform some maintenance on the converter, like 'draining the sludge' as the cover says to do, as well as check any filters, valves, tubes, etc. but I've never played with such an animal and, even though I'm pretty mechanically savvy, I don't want to blow up! Does anyone have any literature, factory or otherwise, that gives a description of basic maintenance tips or procedures, as well as, say, a diagram that shows what all the fittings are, adjustment screws, etc? The thing runs well but it was put in in the late 70s or so and I want to check it out and know it's ok inside... just so I can sleep better! Thanks.
RetroRacer

C3H8
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Re: Vialle Type F

Post by C3H8 » Sat Jun 14, 2014 10:40 am

Look at my posts under my user name. I have written many posts about Vialle regs including the C%, D5 and F5. If you don't find what you require post again or PM me and I'll answer your questions.

Retroracer
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Re: Vialle Type F

Post by Retroracer » Mon Jun 16, 2014 12:55 pm

Hi C3H8, and thanks for your quick reply.

I've included a couple of pics below with some scribbles and questions that I couldn't find detailed answers to - hopefully these will benefit me and anyone else who might have an older Vialle system. The first pic shows the comtroller, the second the mixer on top of an Edelbrock 1406-600cfm four-barrel.
vialle 036-1.jpg
vialle 006-1.JPG
So... where do I "drain the sludge" from? Are there any filters I should clean or change? Should I buy a rebuild kit (diaphragm, gaskets, etc.) after all these years? Besides solenoids, etc. any spares I should carry in the truck so I don't get stranded? What are good initial settings for idle and power valve adjustments?

The system is running well except I'm noticing that priming is not as easy as it used to be - I have to cycle the ignition switch 4-5 times instead of 2-3 like before. Also, I rebuilt the carb last week and the truck fired up perfectly and ran great - on LPG. When I switched to gasoline, it spluttered, came to a stop and I then couldn't start it on either fuel and had to get towed home. It felt like I'd lost spark. It sat for a day, I went to diagnose the problem, checked for spark and it had tons! So I tried to start it on LPG and it fired right up again. Checked for gasoline fuel pressure at the carb and there was none so that sort of explained it. It still will not run on gasoline (turns out my AFC gasoline shutoff valve is plugged and I'll be replacing it.) but that will be fixed soon.

Based on this behaviour, does this mean that because of the gasoline flow issue, the system shut itself down to both fuels and wouldn't start until some time lapsed? Is this normal, or did I just flood it?

Thanks for the help!
RetroRacer

C3H8
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Re: Vialle Type F

Post by C3H8 » Mon Jun 16, 2014 11:17 pm

Ok. Let's start with the initial question. The drain plugs. On the bottom of the reg are two 10MM plugs that communicate with the secondary chambers of the regulator. If you look directly at the front of the reg where Vialle is written one is about 5:30 and the other is about 6:30. One is near the front edge and the other further back near the back edge. They are offset from each other and will drain any oil from the chamber that has collected. Depending on the quality if the propane in your area you may get lots or little. Judging by the fact your vehicle is still running well I would say you have little. On Vialle regs a lot of oil will interfere with the diaphragm movement resulting in poor acceleration and even hesitation on propane. The oil must be drained hot or warm as it congeals when it is cold into a lard like consistency. Run the engine for ten to 15 minutes on propane. Let it cool for a few minutes. Place a container if possible under the reg to catch any oil. It can leave a hard to remove skunk like odour on the fender skirt. If you can't catch it wash it off with some solvent and soap and water. As soon as you remove one of the plugs any residue should start to come out. If nothing comes out there is nothing there. If there is non after removing one of the plugs there is no use removing the other.

The other questions.
Stepper motor: Its not a stepper motor. It is just a solenoid that is open or closed. It is the primer and idle solenoid. It is turned on by the electronic control module (gray box). The module is triggered by key on. If the ignition is turned on but the engine not cranked it will prime the system for two seconds and then shut off. Once the engine is cranked the solenoid is opened by the module as soon as it senses RPM. It stays open as long as the engine is turning. If the engine stalls the module will disconnect the solenoid after two seconds. This module also controls the main lock off the same way.

Under the primer solenoid is a small orifice. If this orifice plugs the engine usually will not start or run but it can be reduced in diameter by dirt. It is only a .030 orifice so it is easy to plugs. Yours must be clear as the engine runs but it can be cleaned with a piece of tag wire. Should you choose to remove the solenoid to check the orifice pay attention. The piston and seat for the solenoid are free floating and have a spring under them. Once the solenoid shaft is removed the piston sticks sometimes and the spring will eject it after a few seconds or when probed. It is easy to loose parts when it pops. Frequently when starting requires several primes the orifice may be getting dirty or the piston is getting stuck in the shaft and not opening all the way.

Idle screw is the one with the 11MM (7/16") locknut closed to the solenoid. Normally in a V* this screw will be 4 to six turns open.
The other long skinny shaft is the balance screw. It is used to smooth out pulsing of the intake air as the intake valves open and close. This is mainly for 4 cylinder engines but does help older V8's also. It also makes adjustment of the idle settings easier.

The larger nut is the opening to the secondary spring. There is not reason to remove this except when rebuilding the reg completely.

The last item is the power valve. It is the adjuster with the 1" locknut. It is set at 2500 to 3000 RPM and controls cruise and full throttle mixtures.

There is one additional part on the top side of the reg quite close to the idle screw I cannot see in the picture. It is a flat brass fitting with about a 3/4" wrench flat. Under it is a tube type screen that picks up any small dirt that gets through the main filter. It has small disk magnets in the center of the screen. Once removed the filter can be unscrewed from the cap. "WARINING IT IS A LEFT HAND THREAD".

Adjustments: Other then minor adjustments to the idle screw to compensate for dirt in the idle orifice it is best to leave the adjustments alone. Seeing as how you have to prime additional times you could try opening your idle screw 1/2 turn to 1 turn.

The problem with your gas is easy to figure out. Even though the solenoid was not working properly you probably got some gas into the carburetor bowl. Once you do this you must get it all out by starting on gas if possible or the minute you turn on the propane the engine floods.. In this case either turn off both the propane and gas if your switch is wired with a center off position or unplug both the main solenoid and idle solenoid and crank the engine until it fires and burns off the excess fuel. Then plug the solenoids back in and restart. In this case the small amount of gas either evaporated or the engine needed sufficient fuel to start cold that it managed to start and quickly burn off the extra gas.

Should you get a repair kit? If the system has more then 100,000K it would be a good idea. Kits are available for Vialle from Proquip at 1-866-692-8132, The kit has instructions including basic set up instructions. As long as the reg is not saturated with oil or the coolant diaphragm is not leaking the reg is probably fine. You will know if there is a coolant leak. When the plug(s) are removed coolant would come out with the oil. Be careful with the plugs as there is a third smaller plug that drains the coolant section of the reg and it is located between the two plugs for draining the oil.

C3H8
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Re: Vialle Type F

Post by C3H8 » Mon Jun 16, 2014 11:23 pm

One clarification. The brass cap I referred to is a normal right hand thread. The tube filter is held in place by a plastic retainer and this is the piece I have indicated is a left hand thread. It is easy to strip the retainer thread if you turn it the wrong way.

C3H8
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Re: Vialle Type F

Post by C3H8 » Mon Jun 16, 2014 11:35 pm

Further to maintenance, There is a filter and magnet system located in the main lockoff. The lockoff is an integral part of the regulator on an F% but the base is removable. Shut off the valve at the tank and run the engine on propane until it stalls. Let it sit for a minute or two and try to start it again. If it starts let it run again until it quits. try one more. If it starts again your valve at the tank is leaking. If it does not start you can remove the filter cap and clean the filter. It is a metal flat disk and can be cleaned in solvent. The magnets are on a special plastic holder with posts and any dirt can be blown off with compressed air. Careful you don't lose the magnets as they do come off the posts. The screws holding the cap on the F5 are normally of the Allen key design. Might be metric. Once cleaned check the O'ring and reinstall the filter and magnets. Slowly turn on the tank valve and check for leaks with soap and water.

Warning. If you have never worked with liquid propane before be careful. You can get a sever frostbite burn. Also work outdoors if possible for ventilation purposes. Propane is heavier then air and sinks to the lowest location where it can pool and be accidentally ignited.

Retroracer
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Re: Vialle Type F

Post by Retroracer » Wed Jun 18, 2014 12:07 pm

Great info, thank you C3H8!

Update: I decided to concentrate on the gasoline side of things yesterday (which I will get into shortly) but I did remove one of the 10mm drain bolts from the bottom of the converter and... no sludge. Today I'll carefully have a look at the idle solenoid and piston to make sure everything's clean.

Back to yesterday. I installed a new Carter fuel pump, a new AFC Model 111 gasoline lockoff (identical to the old one), a new Fram fuel filter between the lockoff and (new) Holley regulator and the regulator itself between the fuel filter and the carb, about 10" from the carb itself. I wired the lockoff exactly like the old one: ground to the engine block, Pos. to a wire that, I assume, goes to the control module behind the converter to get a 12v pulse when you turn the key (haven't checked it for sure as I ran out of time). To add, my fuel selector switch in the cab is a three-way with center position shutting all fuels off.

Once again, no problems starting or running on propane - truck runs great. On the gasoline side though, I can't seem to get a consistent supply of fuel to the regulator. So I began testing the gasoline supply line segment by segment: the fuel pump squirts lots of fuel from its 'Out' port; when I first hooked up a fuel pressure gauge to the exit of the fuel filter (just beyond the lockoff) I was getting 7-8 PSI. I figured, great, I'll knock that down to 4.5-5 PSI with the regulator so the carb doesn't flood and I should be on my way... However, since I couldn't quite set the fuel pressure gauge up on the 'Out' port of the regulator and crank the engine by myself very easily, I decided to just hook it up and try to start the truck (probably a mistake I think!) Well it spluttered a bit but didn't start - I figure I probably flooded it. So I shut the fuel switch off and cranked the engine a few times to get rid of any unburned fuel, turned the regulator pressure down by a turn and tried again - no dice. I finally rigged up something to allow me to hook up the fuel pressure gauge to the regulator and see it while I crank the engine but got NO fuel pressure. So I worked backwards again and, now, I have no fuel pressure coming from the 'Out' port of the lockoff even when the lockoff should be open via the fuel selector switch. Truck still runs good on propane though.

I figure I somehow 'upset' the control module by flooding the engine twice and it just shut off the lockoff for safety. I'll try to start the truck on gasoline from cold this morning to see if there's a difference and keep the propane out of the equation altogether. Am I even close to figuring out what the heck happened??

I'm going to owe you at least ONE bottle of Scotch!!
RetroRacer

C3H8
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Re: Vialle Type F

Post by C3H8 » Wed Jun 18, 2014 5:39 pm

OK. You have the gasoline wiring pictured wrong. The gasoline system is not wired in any way to the control module on the back of the F reg. Your 111AFC can be grounded to the block assuming you engine has a good ground. I would actually run the 111 ground to the body ground or straight to battery. The power wire for the 111 comes directly from the dash switch. It will either be a 3 or 6 terminal switch. The original Vialle switches were black square toggle switches. The center terminals were for the 12 volt power "in" to operate the system. Placed in the center position power came to the switch and did not leave. The outer terminal was used for power to the gas lock off directly and the other went to pin 5 of the propane module. I have to run for now. More later tonight.

C3H8
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Re: Vialle Type F

Post by C3H8 » Wed Jun 18, 2014 7:37 pm

I'm back. Where was I? Oh yeah, the switch. So, to sum up. 12 volt "cranking and run" into the center terminal. 12 volts out on the gasoline terminal to the 111AFC and the fuel pump. 12 volts out to the propane module from the propane terminal. One reminder. These switches are designed internally in an "X" fashion. This means the propane terminal is on the opposite side of the switch from the marking on the front. Same for the gasoline terminal. First test is to ensure there is power on the gasoline terminal. We know the propane is good because it runs on propane. Test right at the rear of the switch to eliminate a faulty switch.

Second item. You might see a second set of wires on the back of the switch. Two horizontal sets of 3. One set is to operate the system. The other is to change fuel tank senders if your system uses the OEM gauge for both fuels. Very common in the 70's and 80's.

Next step. Once you have confirmed power at the "gasoline out" terminal check for power at the 111AFC. If you have power there jump a ground wire to the battery to ensure a proper ground. Change the power switch from neutral to gasoline and back a couple of times and you should hear the 111 click. If so you can now move onto your pump, etc.

You might ask why the propane has a safety shutoff module. Propane is under pressure and in the event of stalling regulations require the fuel to be shut off. Because of this the module senses RPM and cuts power to the propane lock off if the engine stalls.

On gasoline you have a manual shutoff built into the carb. The carb float system will keep the gasoline from flooding the engine so whether you have a mechanical or electrical pump it doesn't matter. All that matters is to ensure the pump is working and the pressure is correct even if the engine is not running. The carb float will stop the flow of gasoline into the bowl as long as the pressure is correct even if the engine is not running.

The next question is, how is your pump wired. It should have a constant 12 volts as soon as you select gasoline. Power should be routed directly from the dash switch to the 111 and the carter fuel pump. If the amperage required is too high use a relay triggered by the propane switch to send power to the lockoff and pump. Other then that you should only have to select gas, wait 5 to ten seconds for the pump to fill the carb bowl and then start the engine. I think if you trace your gasoline lockoff wire you will find they just routed all the wires the same route and your gasoline lockoff wire is not attached to the module.

I reiterate once more. Your Propane module should have nothing to do with the gasoline system. It controls the propane only!

Retroracer
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Re: Vialle Type F

Post by Retroracer » Wed Jun 18, 2014 9:16 pm

Ok, points taken. One thing I forgot to mention is that my fuel pump is mechanical so there's no wiring to worry about. As for my fuel selector switch, I didn't check it but it used to work perfectly before I did all this work to the gasoline system. I know things can just go but I have no reason to believe it's faulty at this point. I'll check it tomorrow anyway.

As for today, here's how it went: I started the truck on gasoline this morning as per my idea mentioned in my previous post and it fired up! Ran for a few seconds then got really rough, as if it was richening up, so I quickly shut off the fuel selector switch to close the AFC 111 and stem fuel flow and... she cleaned up and ran smoothly until the float bowls emptied. That starts to point towards a carburation issue in my book... So, I went to the shop, tore the top off the carb again, checked float height and drop - all good and according to the Edelbrock manual. Put it all back together, tried to start it and she just flooded again! I let it sit for a bit then checked for fuel pressure at the regulator, thinking I needed to turn it down even more - there was no pressure! Checked fuel flow out of the pump again, it was fine so I started thinking that maybe the AFC 111 was stuck closed... I bypassed it and went straight from the pump to the regulator and she just flooded again, even though I had the regulator set at the lowest pressure before the spring falls out of it!

I'm thinking I screwed something up when I rebuilt the carb - I just can't come up with any other explanation at the moment.

In other news, I removed the idle solenoid off the Vialle, and the brass barb that it slides over, and cleaned everything out with Q-tips and WD-40. The spring-loaded piston that slid into the brass barb was a bit sticky but nothing major. I could not find any .030 orifice anywhere though... I figured it should be in bottom of the brass barb, where the piston sits but there's no hole in there to clean. I checked with a good light and magnifying glass: the only hole in the barb is on the top end, where the solenoid housing screw goes. The solenoid itself is just a hollow plastic cylinder that slides over the barb so no .030 hole there either. Then I went to adjust the idle screw. I always screw things like that in at first and count the turns so I know where I started. I barely got half a turn in on the adjustment screw; it wouldn't go any further in and I didn't want to force it (I made sure the 13mm lock nut was backed right up and I had maximum length to work with). I found that strange. Anyway, I didn't want to get too crazy with it so I put it all back together - clean - and, again, the truck runs fine so I don't really think I have any major propane-related issues.

Now I just have to think about that Edelbrock, do some research and see where I might've gone wrong. After all this fudging with switches and relays, I think the main problem is that she's just not swallowing the gasoline but spitting it out instead... might even be a vaccuum leak, who knows at this point. If there are any Edelbrockers out there, I don't mind buying TWO bottles of Scotch :D
RetroRacer

C3H8
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Re: Vialle Type F

Post by C3H8 » Thu Jun 19, 2014 12:21 am

First. Thanks for clearing up the fuel pump. When you mentioned pump and regulator I just presumed you meant electric pump as I have never seen a regulator on a mechanical pump for gasoline but I guess there is no reason one could not be used. From your description I believe you are correct to expect something is still wrong with the carb. One possibility is a hole in the float or a leaky needle valve that the float closes.

As for the orifice in the propane system it is there. It is under the seat the solenoid piston closes on. It is the brass ring in the opening. There is a spring under that seat that will send it flying so if you choose to investigate further make sure you don't let the parts fly across the shop and loose them. From what you describe though it sounds like the orifice is clean. I got your PM and I will send you a schematic of the vialle reg and refer to the part numbers for the orifice.

Lets talk about the adjustment on the idle screw. In previous posts I have described the vialle operation. One of the quirks of a vialle system is the idle screw can be closed too far but the engine will keep running. Vialle has two circuits. An idle circuit controlled by the idle coil, orifice and idle adjustment screw. The cruise and power is controlled by the in line power adjuster in the vapour line. When idling the regulator normally pits out a positive pressure. Once cruise conditions are reached the regulator tries to achieve zero pressure (virtually impossible), so it bounces back and forth between a slight negative and a slight positive pressure. When accelerating the regulator is in a negative pressure state and opens the secondary valve completely.

The quirk is that the idle circuit is supposed to be open enough to keep the regulator in a positive pressure state. Closing the idle screw leans the mixtures, opening richens them. Here's the quirky part. If the idle screw is closed too far it will cause the regulator to go negative pressure. This will cause the secondary valve to open and supply the fuel needed for the engine to keep running. The bad thing about this is the mixtures are richer then required usually resulting in a strong exhaust odour and the priming is impacted because the closed idle screw limits the fuel that is available for priming. You can actually tell when the regulator goes through this transition. Open the idle screw very slowly to check if it is set correctly (its not by the way if it is only 1/2 turn open). Because the idle screw is closed too far the mixtures will actually lean out as you open the idle screw and positive pressure is restored causing the secondary valve to close. If you open the idle screw slow enough the engine will actually shudder slightly and then smooth out as you open the screw a little more as it completes the transition from negative to positive pressure. A normal idle screw will be between 3 to 6 turns open depending on the engine size. As an experiment you can slowly close the idle screw and the RPM's will begin to drop but as soon as you go to far the idle will suddenly smooth out again as soon as the secondary valve is forced open due to a lack of fuel.

Retroracer
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Location: Vancouver Island

Re: Vialle Type F

Post by Retroracer » Thu Jun 19, 2014 8:52 pm

EPILOGUE!:

Well, after all that head-scratchin' and turmoil, it turns out the carb was flooding because the floats were set wrong after all. I found someone, by chance, who's worked with Edelbrocks and Holleys a lot and we tore the carb off again to have a look. It turns out I had done everything right except for the floats - which I set by following the instruction booklet to the letter (read: I overthunk it!) instead of stepping back and realizing that it couldn't BUT flood the way I'd set it up. The needles weren't closing all the way on the seats and gas just kept coming through. Since there was no resistance to that fuel flow, there was no pressure building up anywhere and therefore showing on the fuel pressure gauge! Silly mistake but, frankly, the damn instructions in the carb booklet need to be revised big-time!

She's now running comfortably on gasoline, at about 5 PSI, and I can switch back and forth between gas and propane without any issues, just like before. About bloody time!

On the propane side, I raised the idle a bit and am currently at 4.5 turns out from closed. She seems to like it there and I should be off the power circuit while idling now. It may change slightly again once I start fiddling around with timing a bit but at least the carburation part of the equation is under control. I've got a dual-timing-curve module I'd like to install that plumbs into the distributor wiring and is activated by flicking the fuel selector switch to LPG, and it will add advance based on how it's programmed. Right now, because the engine is slightly higher compression than stock (built for propane) I can't give it the advance it needs because it will knock when I switch to gasoline - even with premium. As a result, I have to run a compromised timing setting that doesn't allow me to take full advantage of the propane's higher octane. Stay tuned!...

C3H8, a HUGE thank you for all your help and info - couldn't have done it without it. I am still interested in that Vialle info you have - never hurts to get even more familiar with the equipment.
RetroRacer

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