quickstang87 Posted April 30, 2011 Share Posted April 30, 2011 I've got a carbed '88 Justly and it's giving me fits. It sat for a year or two and now it seems to be running really rich. If I take the air cleaner off and rev the engine to wide open throttle, fuel actually sprays out of the top of the carb! It's a real dog on the street too. It won't go over about 4500 rpm and 50 mph even at wide open throttle. I have checked the timing and adjusted the valves. The fuel filter is new. Also, before I aquired the car, the carb was rebuilt a few years ago and never solved the problem. Does anybody have any suggestions? Thanks Link to comment Share on other sites More sharing options...
naru Posted April 30, 2011 Share Posted April 30, 2011 Might be a valve problem. Run the motor w/a vacuum gauge on the intake manifold. Link to comment Share on other sites More sharing options...
quickstang87 Posted May 3, 2011 Author Share Posted May 3, 2011 Vacuum is within spec. I don't think it's a valve problem Anybody else? Link to comment Share on other sites More sharing options...
kanurys Posted May 5, 2011 Share Posted May 5, 2011 Not sure about the fuel spitting out the intake, but maybe a semi-clogged exhaust? Though, it sounds like you covered all the other bases except having a working carburetor. Link to comment Share on other sites More sharing options...
quickstang87 Posted May 6, 2011 Author Share Posted May 6, 2011 I thought exhaust too so I cut it off before the cat. It didn't make any difference. Link to comment Share on other sites More sharing options...
naru Posted May 6, 2011 Share Posted May 6, 2011 Vacuum is within spec. I don't think it's a valve problem Anybody else? Even while fuel is spraying out of the carb? Gauge may not show high pressure transients from combustion pressure leaks. A bit of a "fuel fog" above the carb is normal sometimes,but,it sounds like you are talking about something more serious. I know it is not what you want to hear,but,you have engine problems. Think about it,what else is going to make fuel spray out of the carb? Try disabling one cyl. at a time. Link to comment Share on other sites More sharing options...
ferox Posted May 7, 2011 Share Posted May 7, 2011 The Justy carb has an integral duty solenoid. Check the condition of the two wires that go to it. They come out of the top of the carb. What condition is your O2 sensor? Could you be more specific about the fuel spraying out of the top of the carb? Link to comment Share on other sites More sharing options...
nipper Posted May 7, 2011 Share Posted May 7, 2011 I had this and I had to get a rebuilt carb. The float was stuck. Mine sat for 3-4 years. Between the (vile) old gas and other stuff, it had to be rebuilt. I have a source if needed. Link to comment Share on other sites More sharing options...
Quidam Posted May 7, 2011 Share Posted May 7, 2011 I thought exhaust too so I cut it off before the cat. It didn't make any difference. The large canister that bolts to your exhaust manifold is the primary cat. Is this what you cut off? doug Link to comment Share on other sites More sharing options...
quickstang87 Posted May 7, 2011 Author Share Posted May 7, 2011 Does this have 2 cats? When I cut the exhaust, I did it under the car behind the engine. Also, I noticed when the exhaust was cut, the sound of the engine didn't get any louder. I thought that was wierd since I got rid of most of the exhaust. I tore down, cleaned up, and "rebuilt" the carb last night. Good news is it still runs! The bad news is it still doesn't run any better. The solenoid in the carb works on and off okay and the resistance is 42 ohms. Nothing inside the carb was out of the ordinary or excessivly dirty. Now, anywhere from idle to 3/4 throttle the engine revs freely and will go up to about 5000 RPM. As soon as you go wide open throttle, it falls on it's face and fuel vapor comes up out of the carb. We got it up to 55mph in 4th gear last night! So I guess we are making progress. It seems like a problem with the secondary butterfly. Link to comment Share on other sites More sharing options...
Quidam Posted May 7, 2011 Share Posted May 7, 2011 Hi, The one cut off is a resonator, pretty sure. Remove the few bolts that hold the heat shield to the exhaust manifold. The cat is held on by 5 or 6 bolts and is large in diameter. Whe you have it off, you're looking directly at the cat material. Doug Link to comment Share on other sites More sharing options...
nipper Posted May 7, 2011 Share Posted May 7, 2011 There is one huge cat right under the exhaust manifold, that is the only cat. What you may have cut off was the resonator. There is really no replacement exhausts system for this car (do NOT beleive what they advertise as OE replacements). The system has to be fabricated and the rear muffle pipes are weak. How did you "rebuild" the carb. Without a rebuild kit all you did was cleab up the carb. I havent heard of these ever clogging up so i doubt it is the cat. The engine revs freely so it is not the cat. Did you flush out the fuel system by draining the tank, adding good fuel, and runnning the pump and driuaing it at the carb feed line? Have you heard of Dusty's Justy's ? the site does have quite a few diagrams. Also there is the Justy proboard. a little justy community. Link to comment Share on other sites More sharing options...
ferox Posted May 7, 2011 Share Posted May 7, 2011 (edited) How did you "rebuild" the carb. Without a rebuild kit all you did was cleab up the carb. Did you flush out the fuel system by draining the tank, adding good fuel, and runnning the pump and driuaing it at the carb feed line? +1 Seems like your fuel system might still be a little crusty. If your secondary butterfly is binding or you have clogging in the fuel circuits you will have to break the carb down again. I have a used '88 carb assembled and an '88 disassembled carb. I also have a carb rebuild kit NIB for an '88 Justy if you want anything. I am going to Megasquirt my '88. I suggest you check your vacuum advances (there are two) on the distributor. If one of the vac. advance pots isn't working it may cause your problem at WOT. This is not necessarily related to this problem and you probably already changed it, but if you haven't switched out the fuel filter you should do so immediately. Edited May 7, 2011 by ferox Link to comment Share on other sites More sharing options...
quickstang87 Posted May 7, 2011 Author Share Posted May 7, 2011 I did use a rebuild kit on the carb, though it didn't come with a whole lot other than seals and gaskets. I changed the metering valve with a new one and switched a few other things that were in the kit. The carb was cleaned very well and wasn't dirty to begin with, since it had been rebuilt a few years ago. The secondary isn't binding physically, but I'm not sure if the vacuum diaphram that controls it is operating properly. I have to double check. The distributor is advancing per my timing light but I don't remeber what it does when I hit WOT. I did change the fuel filter but it does still have some old gas in it. I'm trying to burn the old crap out before putting fresh stuff in it. It actually has about 50/50 old and new gas in it right now. Just for fun I'll try and pull the cat off and test it again. Thanks a ton for the help! Link to comment Share on other sites More sharing options...
nipper Posted May 8, 2011 Share Posted May 8, 2011 How many miles on this. Have you looked for a vacume leak, eiyher a line valve, or maybe a shaft through the carb? Link to comment Share on other sites More sharing options...
ferox Posted May 8, 2011 Share Posted May 8, 2011 The distributor is advancing per my timing light but I don't remeber what it does when I hit WOT. Sounds like you have the fuel system sorted. Definitely check the distributor vacuum advance pots manually by applying vacuum to them and checking for back and forth action of the linkage. Also check the ditributor wiring...the Justy is somewhat notorious for brittle and broken distributor wire insulation creating running problems. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now