opus Posted June 21, 2007 Share Posted June 21, 2007 Heres whats going on........... I changed plugs, which were real bad. The gap was burned out to about 1/8", they were worn!! Put plugs in, gapped them to whatever they should be .044 I think it was. The thing has a horribly rough idle now. It feels like a vacuum leak but I have checked everywhere and found nothing. I bumped the timing up a little bit too, to see how that would work. The thing runs great and plenty of snap [for what it is]. What am I missing?? Its something that you would cure on a normal carb by adjusting the idle screw. Link to comment Share on other sites More sharing options...
DaveAP Posted June 21, 2007 Share Posted June 21, 2007 Did you take the air cleaner off when working on it? May have not reconnected all the vac lines. Link to comment Share on other sites More sharing options...
daeron Posted June 21, 2007 Share Posted June 21, 2007 I presume that its an SPFI, since you said "Its something that you would cure on a normal carb by adjusting the idle screw." Check all spark plug wires, double check the rotor retaining screw, make sure none of the plugs are loose, and MAYBE try gapping them a LITTLE bit tighter. 0.44 is the top side of the range specified, the bottom end is I believe 0.36" (whatever the decimal point is) Link to comment Share on other sites More sharing options...
misledxcracker Posted June 21, 2007 Share Posted June 21, 2007 .044 is OK on the plugs from what i can tell... i run NGK's with a .044 gap. When my car had a rough idle and even started to misfire after awhile, it was a vacuum leak. I'd check around the intake for hissing noises... Link to comment Share on other sites More sharing options...
opus Posted June 21, 2007 Author Share Posted June 21, 2007 Its carbed. There are only 3 vacuum hoses on this thing. All the others are plugged. I replugged the dead one and the others are hooked up. I think I was told there is an idle mixture screw, but it is of no effect if you adjust it. Doesnt make sense, so I never persued it. It is running rich, but no idea how to lean it out. Choke is fully opened. It is the Hitachi carb. Link to comment Share on other sites More sharing options...
Gloyale Posted June 21, 2007 Share Posted June 21, 2007 Try replacing the wires, cap, and rotor as well. The mixture screw is dead center bottom of carb, capped by a rubbery plug. You have to dig out the material before you can see the screw. Clockwise=lean, couterclockwise=rich. Doesn't help much if any from my experience. Once you ditch the vaccum setups on these carbs you are shooting in the dark as they were designed with a fair amount of vaccuum regulated items in the system. Probably running rich because of the bowl vent being scewed up with no vaccum to control it. Link to comment Share on other sites More sharing options...
opus Posted June 21, 2007 Author Share Posted June 21, 2007 I've had this car for 7 years with no hoses on it, and it has run great, never an issue. If the screw is of no use, it is there..........why? Can you point me to the bowl vent?? I'd glady stick a hose on it to see what happens. Link to comment Share on other sites More sharing options...
Gloyale Posted June 21, 2007 Share Posted June 21, 2007 I've had this car for 7 years with no hoses on it, and it has run great, never an issue. If the screw is of no use, it is there..........why? I think on a perfectly sealed, new carb, it works to make a fine adjustment to match the carb to the engine,fuel ratio wise. But when these carbs get old they get leaks around the throttle shaft bushing. This is has a big affect on the mixture, and the screw isn't designed to compenstate for such a big change. It just doesn't have the range. Bowl vent. Well the bowl vent vaccum valve is (or was) clipped onto the upper drivers side of the air cleaner. One hose goes to vent on carb, the other goes to the vented solenoid, mounted on the intake, near the air temp switch. The solenoid is supplied with vaccum form the intake, with a check valve in it before the solenoid. Now there is also the air control vaccum valve. Similar looking to the bowl vent, but with 4 hoses and a cap on the 5th. Mounted to a bracket very near the thermostat housing, under the aircleaner a bit. The bottom/thinnest tube be T'd into the same line from the solenoid just mentioned. 2 larger lines going into the sides should be coming from near the base of the carb and returning there. The line straight out the top goes to the aircleaner. The same vaccum line that supplies vac to the carb choke pulloff and the secondary diagphrams, should T and have a line going up to the aircleaner to the idle compensator (note the small orifice plug needed in this line) There are several other systems (anti afterburn, EGR, Intake air temp control) that are all vacuum dependant. Hard to say what effects removing some or all systems had. As for running rich I'm sure vaccum issues are to blame, but I think you're rough idle may just be plugwires. Link to comment Share on other sites More sharing options...
opus Posted June 21, 2007 Author Share Posted June 21, 2007 I'll do wires and such today. As far as all those other things and "t's" and such, they are all gone. If the throttle shaft was leaking, it would give me lean. I'll find that screw and see what it does. What I had to do in the meanwhile was to turn the idle screw up about 1 turn, so it would idle. It seems to be worse when it is cool out. I manually played with the choke and that has no effect. I sure wish someone would come up with a carb switch for these. You know, a basic simple carb, like a Carter YF. The Weber doesnt impress me. Maybe a carb off a Pinto or something. If someone had a spare Hitachi they didnt need, I'd rebuild it and go from there. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 21, 2007 Share Posted June 21, 2007 The Weber doesnt impress me. Maybe a carb off a Pinto or something. Funny you should use that analogy - the Pinto carb IS a weber. It's a Holley/Weber 5200 which is a licensed copy of the Weber DFV series (which itself is a mirror image of the DGV we all know and love). The Weber DGEV is simpler than the Pinto version by a pretty wide margin. I highly doubt you have seriously looked at a DGV if you are impressed with a Pinto version and not a straight DGV series. As carbs go they are nearly as simple as you can get for a two barrel. For the reccord you probably have a vac leak. Spray around with carb cleaner before you mess with the carb any. The idle mixture is factory set and should not require changing ever. I haven't run across many Hitachi's with worn throttle shafts - found a few Weber's with that problem but the Hitachi's don't seem to exhibit that deficiency too often. At 210,000 my sedan's Hitachi still ran *ok*. Startup was like waking the dead, but once it warmed it was fine. The biggest complaint I have about them is the low-end grunt - there isn't any. I'll take a Weber over a Hitachi (owned half a dozen of each), and SPFI over both of them. Incidentally have you considered the SPFI swap? If you have any kind of decent yards around you SPFI is cheaper than a new Weber. It seems daunting at first but after you have done a few it's not such a huge deal anymore. GD Link to comment Share on other sites More sharing options...
opus Posted June 21, 2007 Author Share Posted June 21, 2007 I'll give that a go too, thanks. Nothing around for 120 miles. I have no interest in an injected engine. I like carbs....except for this one. :/ I like simple carbs. 1 vacuum hose and no wires. Didnt know about the Pinto being a Weber. Whats it like to rebuild a Hitachi? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 21, 2007 Share Posted June 21, 2007 I'll give that a go too, thanks. Nothing around for 120 miles. I have no interest in an injected engine. I like carbs....except for this one. :/ The SPFI is far and away the best fuel system for the EA series engines. Better econemy, power, and reliability. I like simple carbs. 1 vacuum hose and no wires. Unless you run a water choke, you'll need a power wire for the choke (and possibly for the idle-cut solenoid as well which is nice to have), and there's going to be two vac hoses - one for the distributor (ported), and another for the EGR (late ported). Didnt know about the Pinto being a Weber. Whats it like to rebuild a Hitachi? Excersize in futility for most people. They are complex, and it's difficult to find quality rebuild parts for them. Took me 8 attempts before I was proficient (I mean really proficient - such that it runs as new) at rebuilding the Hitachi's - even then they don't have the power and are finiky because of the crappy chinese rebuild parts (sticking floats, etc). I got fed up with the Hitachi's and threw the dozen or so that I had in a dumpster one day and haven't looked back. I have two SPFI and two Weber's and........ no more problems :-p. GD Link to comment Share on other sites More sharing options...
opus Posted June 21, 2007 Author Share Posted June 21, 2007 SPFI is more reliable than a carb??? There is no room for breaking down in this country, its a long, lonely, dark, cold walk if you break down. EGR valve is gone, so its down to 1 vacuum hose for the distributor. I forget about the choke wire. The surely dont want you to be able to adjust the choke on these, do they? Interesting about the Hitachi. Glad I found out before I tried it. Link to comment Share on other sites More sharing options...
opus Posted June 22, 2007 Author Share Posted June 22, 2007 Nope, it wasnt the wires or anything ignition related. I think you are yanking my chain, there is no idle mix screw on the front. At the bottom center there is a aluminum piece with a threaded plug in it [that you cant get out]. It kinda flops around a little, whats that? Used carb cleaner and didnt find much that way either. Carb is plenty clean now though. :/ Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 22, 2007 Share Posted June 22, 2007 There is an idle mix screw on all Hitachi's - it's blocked by a factory installed roll-pin in the front of the carb base. You need to spray around the whole engine to look for leaks. Not just the carb. GD Link to comment Share on other sites More sharing options...
opus Posted June 22, 2007 Author Share Posted June 22, 2007 I did the intake, nothing. I looked at the front for a while. How do you get that thing off? Its right between 2 vacuum hose fittings, right? Interesting post: http://www.ultimatesubaru.org/forum/showthread.php?t=57524&highlight=adjust+carb Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 22, 2007 Share Posted June 22, 2007 I did the intake, nothing. You may indeed not have a vac leak then. Start pulling plug wires one at a time as it idles and see which cylinder isn't firing. You may have an ignition problem. It just happens that many times when folks are messing with plug wires and such they knock loose an existing vacuum line. I looked at the front for a while. How do you get that thing off? Its right between 2 vacuum hose fittings, right? Actually I think it's well below those - IIRC it's in the "throttle base" of the carb - which is made of cast or sintered iron, and the roll pin is generally rusted in place. Those that I have seen removed were done so with a die grinder. Incidentally, the iron throttle base is the reason why the Hitachi's rarely suffer from primary throttle shaft wear. The Weber's are all-aluminium and as a result wear much faster. Bronze bushings or small pin bearings are often installed in the Weber's upon being professionally rebuilt - if the pin bearings are used they are basically indestructible, and for this reason rebuilt Weber's are often better than their (ostensibly) "new" bretheren which are now made in Mexico. The Mexican versions also sometimes aren't put together correctly as the quality control seems to have fallen. Still an excelent carb though as the quality issues, while being somewhat annoying, are generally easily rectified. At any rate, you should NOT have to adjust the idle mixture. Look elsewhere for your problem. I can't stress this enough. Interesting post: http://www.ultimatesubaru.org/forum/showthread.php?t=57524&highlight=adjust+carb There's lots of good info in older posts. It's just wading through the thousands of threads, and 10's of thousands of posts (gawd - I still have a hard time accepting that I've got over 8,000...) on here. GD Link to comment Share on other sites More sharing options...
opus Posted June 23, 2007 Author Share Posted June 23, 2007 So far, it seems to have been the anti-diesel thingy. Link to comment Share on other sites More sharing options...
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