88 Yugo GV Will not warm start, etc

Discussion in 'Front Wheel Drive Fiats' started by FAMICOMASTER, Apr 25, 2019.

  1. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    Car starts first crank cold every time. Car runs for an hour. Shut car off. Car will sputter when trying to restart and then stop firing entirely until the next day. Any ideas?

    Also, the car will not accelerate in third gear at all. It won't go any faster than about 40, which is achieved in second and held in third but nothing more, even on flat land. Downhill it will get to about 50 or so but once the ground levels out it falls back. I'm suspecting ignition advance or electric choke.

    Carburetor is freshly rebuilt, it's barely done 10 miles since being fully rebuilt.

    It will overheat sometimes but I get the feeling it needs a coolant flush and a new expansion tank, which I already have.

    40,397 miles.
     
  2. beezee

    beezee True Classic

    My guess is that the choke is staying on, at least partly.

    Brian
     
  3. carl

    carl True Classic

    Location:
    Virginia
    Don't get target fixation on the carb, check you ignition timing at idle and make sure the timing advances with revved motor.
     
  4. ghostdancing

    ghostdancing True Classic

    Location:
    italy
    did you already checked the fuel pump?
     
  5. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    How do I check this?

    Timing seems good, but it doesn't feel like it's advancing. Vacuum switch might be bad, I'll try bypassing it later.

    Fuel pump puts around 5psi consistently, warm or cold irregardless of engine speed.
     
  6. carl

    carl True Classic

    Location:
    Virginia
    Easy to check the choke, take air cleaner lid off and determine the choke plate is fully open (vertical) when engine is warm.
    When you say timing seems good, does that mean you checked it with a timing light?
     
  7. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    No, I don't even have access to a timing light, but the engine will start and continue to run just fine until you shut it off - At which point it won't start back up. It doesn't feel like it's missing or rough, and it doesn't make any odd sounds (besides the exhaust leak).

    The timing is obviously not the problem, if the timing was off it wouldn't start at all and it wouldn't run very well.
     
  8. ghostdancing

    ghostdancing True Classic

    Location:
    italy
    anyway i would be sure that spark plugs, leads, distributor and coil are spot on..
     
  9. gene cooley

    gene cooley Autocrosser

    Location:
    Henrico, Va
    Return fuel line may be plugged causing a vapor lock when hot. BUT, that shouldn't cause any long term starting problem. It should clear up as soon as the engine cools.
    Half hour maybe.
     
  10. carl

    carl True Classic

    Location:
    Virginia
    I hate to harp on a single issue but an engine will start and run over a very wide range of ignition timing. Basis timing lights are pretty cheap and if you work on old cars it should be part of your tool collection.
     
  11. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    Would this affect float bowl pressure? This seems like the most likely problem to me right now - When I first disconnected the fuel line to rebuild the carburetor there was quite a lot of pressure released from the carburetor's side - No fluid, but it was obviously not venting.
     
  12. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    This is the only old car I work on. I have a parts car but that doesn't really count. My other two cars are both Cadillacs, and they both have electronic ignition and port fuel injection.
     
  13. gene cooley

    gene cooley Autocrosser

    Location:
    Henrico, Va
    Yes, "it could affect the pressure". What you are seeing could also be normal for a carbed Yugo with then current emission controls.
     
  14. carl

    carl True Classic

    Location:
    Virginia
    I have always removed the return lines on my Fiats with no issues.
     
  15. gene cooley

    gene cooley Autocrosser

    Location:
    Henrico, Va
    Same here but I don't remember if I ever pulled one with the engine hot or having run within an hour or so. Probably did, don't remember. There was always pressure at the gas cap, (not for long after the car was shut off) not sure it extended to the carb but it was a closed system so it most likely did.
    My "bought new" '72 128SL had a similar problem with hot starting and the return line was plugged in the return port. This was after it was a couple of years old. The Yugo carb has been cleaned, if there is a blockage it's probably in the line.
    Someone has already mentioned this, but it's still kind of strange. The blockage in my 128SL was a very dead fly jammed head first into the return port. It couldn't have come through the strainer screen at the carb and I doubt it could have made it through the centrifugal vane pump intact. Removing it solved the hot start problem.
     
  16. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    New discoveries:

    The vacuum advance on the distributor was not even attached - I disconnected the plug wires to connect it and must have gotten them mixed up, since the car wouldn't start when I first cranked it, though I swapped two of the wires and it fired up just fine. I really should have taken a picture, does anyone have a firing order and what orientation the distributor should be in?

    Once it started, it seemed fine and the idle dropped a bit. I assumed this was because I had connected the vacuum advance and the PCV valve (the hose was torn and disintegrating, so I replaced it, but it wasn't on the engine for a few weeks). Backed out of my driveway and went halfway around the block, but when I took it out of gear to reverse and turn around, it started to die. Gave it some gas and it stayed running for a few more seconds, but eventually sputtered to a halt, and it wouldn't fire when cranked.

    Swapped some of the plug wires again because I had doubts about my (admittedly poor) memory, and it still would not fire. Accelerator wide open it seemed like it was firing, no abnormal sounds... It just didn't want to run. Eventually with blind luck it got started and ran for a minute or two at idle with the accelerator on the floor, enough for me to turn around and crest the hill to coast back home after it died again. Pushed it into the garage and haven't checked anything since, but this problem was nonexistant until I acted the fool and swapped around plug wires by accident.

    Thoughts, comments, help?
     
  17. ghostdancing

    ghostdancing True Classic

    Location:
    italy
    firing order is 1342, the distributor rotor turns clockwise
     
  18. carl

    carl True Classic

    Location:
    Virginia
    Sounds like you might have a restricted fuel supply and the car is running out of gas after a few minutes.
     
  19. gene cooley

    gene cooley Autocrosser

    Location:
    Henrico, Va
    Also, your small Chinese fuel pump mounted up high where it's "convenient" may not be up to the job.
    Also again, you may have a leak on the suction side of the pump and it's pulling air not fuel. This could be at the fuel pickup line.
    Plugged return.
     
  20. FAMICOMASTER

    FAMICOMASTER Yugo owner

    Location:
    United States
    It's almost certainly NOT a fuel problem. It's not running out of gas, even if I pour good fuel down the throat of the carburetor it will still refuse to start.

    These recent problems were nonexistent until I started messing with the distributor - The car ran pretty well on it's own beforehand, albeit a bit rough and it would not warm start. I think I can justify those in part by pointing out that one of the cylinders was disconnected from the distributor completely and that the vacuum advance was unplugged and open - No plug in the port.

    How can I check a plugged return line? I can't exactly take the whole line off the car, it's a decently difficult job since the metal hardline goes from the interior underneath the floor and into the engine before it becomes a very short piece of rubber hose connected to the carb.

    Where else can I mount this electric fuel pump where it will have power and will not require drilling holes in things? I'm not going to go back to the mechanical pump, it'd be such an insane amount of work for potentially no change at all other than maybe causing it to crank longer before starting.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice