88 Yugo GV Carb to EFI

Discussion in 'Front Wheel Drive Fiats' started by FAMICOMASTER, Mar 19, 2019.

  1. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    I'm sick and tired of this carburetor. It's been nothing but trouble since I got the car. I know it has ignition, compression, and air because it will run if I put gas directly down the intake. I know it has 5psi of fuel pressure (As recommended by the service manual), and I've cleaned the needles and jets several times.

    My remaining options include "fix carb again" or "convert to EFI"

    Does anybody have any suggestions for a more permanent carburetor repair or each (preferably cheap) EFI conversions? I considered pulling EFI components from a GVPlus, but I simply cannot find one to get parts from and it seems like an incredibly involved job, not to mention expensive.

    I've heard that some Fiat Unos / Pandas with EFI systems are easy to convert with, but I don't know any part numbers or anything to track down these parts with.

    Any thoughts? Comments? Car has just over 40,000 original miles on it and as much as I want to keep it completely stock, having such a nice looking car does me no good if it won't move without a winch.
     
  2. Kevin Channer

    Kevin Channer True Classic

    My two cents, seat of the pants suggestion sort of depends on your location and emissions laws; if possible I believe your easiest solution is to de smog the car. Most Yugo carb issues are due to the compromised add on emissions stuff. I would think a used or NOS weber carb from an X 19 or 128 without the complex recirculation should run smoother. Fuel injection conversion is quite a bit more involved and parts for the Yugo version particularly scare. A Fiat sourced EFI made from used parts is possible but still a bit involved. Now hopefully a few of our technical minds will chime in :D
     
  3. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    I've been working towards removing emissions equipment as much as possible - While not legal to remove the cat there's nothing saying I can't remove the air pump and let the cat overheat and die a slow and painful death. There are no inspections around here to worry about.

    Smoothness is not the issue, and I'm not doing this to get more power out of the little engine... It refuses to start. This carburetor was brand new less than a year ago, and I still have the original. Both have the same issue, which is that they work incredibly intermittently.

    The newer carb will occasionally let the car start and run consistently, but once you shut it off it will not start back up. Sometimes it just won't start at all. Like I said, it's not an engine problem because if I pour fuel down the throat of the carb directly into the intake it will fire right up.

    Previous carb was original to the car, and the one that's on there right now is practically brand new (NOS) parts. I have a hard time believing that it's already gone bad after such a short time, so I'm going to disassemble it fully when I get the time, but at this point I'm tired of rebuilding and replacing this stupid thing.

    Is there a more reliable option available, if not an EFI conversion?
     
  4. Kevin Channer

    Kevin Channer True Classic

    Given that the carbs are new or newer, my guess is the fuel source is contaminated ie rusty tank? or fuel line? clogged fuel filter? perhaps a pour in fuel cleaner and a see thru fuel filter (inline) to view if debris is coming thru to clog the carb.
     
  5. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    I haven't tried fuel cleaner but I already have a clear filter and a new pump - The mechanical pump on the engine failed long ago, I'm told. It's an electric pump mounted next to the radiator.

    The fuel filter *appears* clean, and when I tested the fuel pressure I also ran it into an old mason jar - It looked pretty similar to new gas to me.

    Is there a specific drain on the tank? The gauge reads full and I don't want to have to drop a tank with 9 gallons of gas in it.
     
  6. Kevin Channer

    Kevin Channer True Classic

    You mentioned what may be an important clue: the electric fuel pump and its location, maybe your intermittent running is a vapor lock brought on by the heat exposure. Because of the intermittent nature such a problem can be hard to diagnose. The good news is that the mechanical pumps are cheap and usually reliable, since you are running everything else stock, I would go back to the mechanical pump. It maybe safer too.
     
  7. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    I'll consider this. Any idea where I can get a replacement mechanical pump for cheap?

    The mechanical pump being on the front of the engine seems like it would get more heat than above the AC condenser or near the radiator.

    I should also mention that the engine turns freely when you turn the key - it just rarely "catches," as they say and actually starts.

    I follow the starting instructions in the owner's manual: Turn key to run, fasten belt, check for neutral, double clutch and pump accelerator once when cold or halfway for warm, turn to run. Never run the starter more than 5 seconds at a time and wait 20-30 seconds between cranking.

    Following this procedure, however... The engine will spin over just fine, maybe fire once or twice but nothing. Sometimes the engine will start and die, and the following attempt to start it, it will fire once or twice and stall, after which it won't fire again unless I pour gas down the carb, and even then it will idle incredibly high for a few seconds and die again. No tach so I'm going by ear - This is what happens:


    The fuel gauge was not working when I shot this video, but it shows pretty well what is happening, as do other videos on the channel. It runs and drives once it's started - 10 to 15 minutes of driving it around to charge the battery and it was totally fine, aside from a clunk in the suspension I've since fixed.

    It has an exhaust leak, too, if that is of any importance:
     
  8. Kevin Channer

    Kevin Channer True Classic

  9. ghostdancing

    ghostdancing True Classic

    Location:
    italy
    did you checked that electrics (distributor, powerleads, spark plugs) are all working fine? electric fuel pump works better if installed close to the tank, and not higher than the fluid level in the tank itself
     
  10. kmead

    kmead Old enough to know better

    Location:
    Michigan
    First, I would suggest not going down the EFI route as it requires significant work and parts that will be hard to source. It adds a myriad of variables to the problem

    Secondly, like all things its important to go back to the basics.

    How old is the fuel in the car? If it is a year or older, I would pump it out and replace it with fresh gas. Once the car runs properly you can put the fuel back in along with fresh fuel to use it up. The car won’t run the best on it but it will be fine with primarily new gas with old gas mixed in. Assuming the fuel pump pumps gas you can use it to pump the fuel out into a safe container.

    As you state, the car will run if fuel is poured down the throat of the carb. This tells us that the ignition system is working properly. If you pour fuel down the throat of the carb it will run until it exhausts the quantity of fuel you have puddled into the intake. So it is getting spark and things are timed properly to run.

    This suggests the problem is around fuel supply. The things to check are the fuel pump itself, the electrical supply to the fuel pump and the fuel lines, valves and filters.

    Is the fuel pump getting electricity when it should? Have you removed the hose off the carburetor and then turned the key to ON to verify the pump is actually outputting fuel at the carburetor? Does it do the same when you turn the key to the starting position? Meaning when the starter is running is the fuel pump running and delivering fuel? If yes to these then the problem is in the carburetor. If no then you need to change the fuel pump wiring to ensure the pump runs when the starter is running and runs when the key is in the on position.

    For the fuel supply, start at the back of the system and trace the fuel supply forward to verify it has not been compressed or damaged. Generally if you break the rubber line loose at the tank, fuel should come out of either the hose to the engine or the tank itself so carefully loosen each hose connection and verify that there is fuel available. I would replace the short sections of fuel hose that link hard lines as you go, they are old and deserve replacement. Verify that the inline valves in the lines are oriented in the correct direction, these are small plastic or cast metal parts usually inline in the gas line that help prevent fuel going backwards in the system after the car is shut off, they could be before or after the fuel pump. Work your way to the fuel pump testing periodically until you get a consistent flow of fuel in the start and run positions of the ignition switch. Once this is achieved the car should start and run reliably assuming there is no other issue in the carburetor.

    Personally, I would return it to an OE mechanical fuel pump. They are cheap, they are reliable and the fuel stops flowing when the engine stops. It will also get rid of several safety issues an electric pump has.

    If one does keep the electric pump, it should be next to the gas tank as electric pumps push well but they don’t pull fuel well. This would neccessitate moving the pump to a safe position under the car and running wiring and preferably adding some safety systems to ensure the pump stops running if there is an accident but we won’t cover that here.

    So what if it is the carb that is the problem? Time to open it up and verify there is fuel in the bowl, verify there is not crud in the bowl and all the associate orifices. Clean it all. Then set the float level which should have been set at the factory but there is no guarantee it was done properly. An improperly adjusted float will keep fuel from entering the carbs float bowl. Put some fuel in the bowl, close it up and see if it runs using the fuel in the bowl without the fuel pump running (meaning pull the electrical supply to the pump). It should start and run until it exhausts the fuel in the bowl. Assuming that all went well reapply power to the pump and let it prime the bowl by turning the ignition to on and letting it run for 30 seconds.

    With any luck you are all set. Report back after chasing through all of this.
     
  11. carl

    carl True Classic

    Location:
    Virginia
    How long has the gas been in the car? I ask because when I was rebirthing a 124 spider that had sat for years I got the same symptoms you had, gas flow was good from tank, car would not start or on rare occasions when it did it would not stay running and it always ran when I poured gas in the carb (this is the key symptom). Turns out there was a nice layer of water in the tank which is heavier than gas and is all that the gas tank pickup provides to the motor. No matter how much new gas you put in the tank, the water always keeps it away from the pickup. Get a small container of gas (I usually use a one quart oil bottle or a 2 gallon lawn mower gas can) and run a hose from the pump to that container and see if the motor starts and runs OK.

    The nice thing about an electric fuel pump is you can use it to drain your gas tank by running a hose from the pump to a container and just turn on the ignition and let it pump the tank dry.

    Stick with the electric pump. Don't go to EFI, when things all work correctly a carb is fine, I ran all my 128s and X1/9s with carbs even when the Xs came with FI.
     
  12. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    The negative terminal was loose but considering the engine would spin over fine I can't see that being an issue. I tightened it anyways, no change.

    I checked for spark, the distributor has spark at all four contacts to ground. Spark plugs look a bit on the old side, but otherwise they were all in-spec gap wise and they all still produced a good spark out of the engine.

    The electric pump was installed here by the previous owner when the mechanical pump failed, and I'm probably not going to move it. There's convenient access to everything and I don't have to cut any hoses to mount it here, so I'll leave it where it is until it becomes a problem, at which point I'll probably switch back to the mechanical pump as mentioned earlier.
     
  13. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    This is a good point, I'm not exactly sure how long the gas has been in it.

    I'll drain the tank this weekend or whenever I can and see what comes out, the battery is totally shot for now but I think I should be fine running it on the 10 amp charger I was using. Battery won't even take a charge anymore, and it leaked all over the floor in my garage last night... It was a 2-year Wal*Mart battery and it ended up lasting over 5 years... I think I can live with a new one at this point.

    Like I said earlier I'll probably stick with the electric pump until something goes wrong, in which case I'll attempt to repair the mechanical pump on the engine or replace it, whichever is cheaper and easier at the time.

    When all things work correctly a carb is fine, yes, but now that things aren't working fine... It becomes a serious culprit.
     
  14. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    Fair enough, that's what I figured. I have a second car (and drivetrain as a result), so I figure though that if I'm not going to put the work into this engine, I'll rebuild and set up the other engine (also a 1.1) with EFI as a replacement in case this one fails for some reason. It has no carb on it anyways, so I might as well try and find something for this engine to get it to run without starting fluid.

    I'll do this, other guy suggested it. I think I might dispose of the old gas instead, though, since I'm not terribly concerned about keeping it around.

    Yes, it's a tiny Chinese pump and it makes a ticking sound when it's running, I can hear it run when the ignition is on and when turning the engine over.
    Yep, already did this too. Previous owner told me that it wouldn't run for more than a minute or two because the fuel pump wasn't running right - This turned out to be a connection issue and now it pumps the pressure required as long as the key is in the ignition, starting or not.
    Pretty sure it is

    Opening the choke and throttle blades, I can definitely see some sort of fluid inside the carburetor when you gently rock the car - I can see the waves. I'll take it apart later if draining the fuel and replacing it with new gas doesn't work. If the problem is actually old fuel / water in the fuel, then I can't see reason to disassemble and essentially rebuild the carburetor for nothing.
     
  15. carl

    carl True Classic

    Location:
    Virginia
    When I pumped the gas out of my spider tank, I first pumped some into a clear container and was shocked to see that maybe 1/3 of the "gas" was something else, the fluid separate line was pretty clear and then realized that other stuff, the bottom layer, was water. I know it's sad, but I would toss all nine gallons of gas in that tank, your local recycler should be able to take it. If there is a drain plug on the bottom of the tank, open it up after sucking out all you can with the pump to make sure everything is out, water will always be the lowest level and you want it all out....keeps your gas tank from rusting out too.
     
    kmead likes this.
  16. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    Not that sad, the gas was effectively free with the car when I got it. I'm going to attempt to drain most of it out tomorrow, and I've got about 4 gallons of gas in cans in my garage to put in the tank to try and start it with. Is there an easy way to drain the carburetor's bowl without disassembling it?
     
  17. kmead

    kmead Old enough to know better

    Location:
    Michigan
    Popping the top of the carb is a pretty simple circumstance. Beyond that your other choice is just running it through the engine...
     
  18. carl

    carl True Classic

    Location:
    Virginia
    Agree with K, remove the top of the carb and use a turkey baster to suck out the gas in there. Don't forget to replace any fuel filter.
     
    kmead likes this.
  19. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    I emptied the entire contents of the gas tank into some 5 gallon gas cans and had it recycled, after which the fuel gauge still read full. Ouch.

    Put a few gallons of new gas into the tank and let the pump prime - Saw gas inside the filter and there was fuel coming out the end of the tube the pump was attached to. All good here.

    Attach the fuel line back to the carburetor and try to start it. Nothing. Still fires with carb cleaner. Took the screws out and pried the top of the carburetor off, expecting the worst...

    Empty. Dry as a bone, not a drop of fluid of any kind in the bowl. Absolutely nothing and it looked to have been that way for a while. There's 5-6PSI at the end of the fuel line before the carb, and there's free flow from the carb's fitting to the seat of the float when the floats are low, and the fuel flow stops when the floats are high.

    What could be causing this? I don't even have a clue anymore. The carburetor is definitely the issue, but I haven't got a single clue as to how this could happen.
     
  20. kmead

    kmead Old enough to know better

    Location:
    Michigan
    Something is keeping the float up and the needle valve is closing the opening and forcing the fuel to return to the tank or the needle valve is stuck with the bore
    • Is the needle valve freely moving when the float moves? Have you removed the float and the needle to verify the orifices that feed fuel in are clear and allow fuel to flow?
    • When holding the top of the carburetor vertically with float pivot hinge above the float, the float hanging downward on its pivot, the tang should be contacting the needle valve and the float arm should be basically vertical and parallel with the carb top. The gap from the float to the carb top should be 5-6mm and the needle valve should be fully closed on its seat, is it? If not then the float is improperly adjusted. Bend the tang that engages the needle valve until you have the right gap and position of the float and the top of the needle valve is against the stop in the bore.
    • When holding the top of the carb horizontally, does they float now drop 15-20mm so there is an approximate 30°angle of the float arm to the carb top? Does the needle valve follow the float downward freely? If no then the float stop is improperly adjusted, adjust the stop tang until you have plenty of downward angle and the needle valve is no longer on the stop in the top of the bore.
    • Did you pour fuel into the bowl and see if it will start and run that way? It should start and run for a while. If not then the carb should be cleaned completely.
    • As an aside, the fuel entry to the carb I would assume has an entry and a return to the tank. The return to the tank is usually a smaller restricted opening even though it may use the same size hose, which may not be obvious. Is the supply on the correct side?
    At an event we had a carved X running poorly. Took the top of the carb off and there was a bug in the float bowl, dead but in there. How did it get in there?
     

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