Guest iskone Posted June 1, 2005 Share Posted June 1, 2005 Let just start by saying AAAARRRRGGGGHHHHHHH So after the fire the parts store didn't have all my parts and I rigged up some fuel line. Now 2 & 3 pour fuel when I turn on the fuel pump. I didn't put the base plate on but I don't see what difference that would make. Anyway heres a pic showing where the fuel pours out. Why does my car hate me? I always treat her right. I think we might need to take a break. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 1, 2005 Share Posted June 1, 2005 Ok that was weird. I tighten the screws on the carb cover before I even put on the new fuel line and they were all very tight. So I pulled the covers off and basically all I did was wipe off the surface of the carb and the gasket and now they don't leak. Lesson: carbs catch on fire check gaskets sounds like a given but the o-rings were ok. Isk Quote Link to comment Share on other sites More sharing options...
mark Posted June 1, 2005 Share Posted June 1, 2005 My webers did that one time. The float was hung open and the bowl would overfill and run out the side of the carb. Take the tops off and make sure the floats can move freely and are not gunked up. Mark Quote Link to comment Share on other sites More sharing options...
preith Posted June 1, 2005 Share Posted June 1, 2005 Iskone, why isn't this continued on your other thread? You probably had this condition when the carb caught on fire. Regardless of the gasket on top sealing very well, when the car's at a stand still the fuel should NEVER be high enough to flood the jet chamber. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 1, 2005 Share Posted June 1, 2005 Mark, I check the floats when I pulled off the covers and they seemed fine I might spray them with carb cleaner just to be safe. Preith, I kind of thought it was a different topic. Now that I think about it I should have posted in the fire thread. See this is way we can't ban the dumb guys I got all the leaking to stop last night but since my header wrap was now soaked in gasoline and the carbs had some fuel on them I decided not to turn over the motor. I don't think I had this problem when they caught on fire becuse only the thrid carb was the culprit. When the 3rd carb was on fire it caused the 2nd to burn too. I think it would have burned alot more then it did if they were pouring fuel like last night then again I did shut the fuel off as soon as the fire started. Isk Quote Link to comment Share on other sites More sharing options...
mark Posted June 1, 2005 Share Posted June 1, 2005 Also make sure the floats, float. Another culprit could be the valve on the float is bad and not closing all the way when the floats are up. Quote Link to comment Share on other sites More sharing options...
preith Posted June 1, 2005 Share Posted June 1, 2005 Also make sure the floats, float. Another culprit could be the valve on the float is bad and not closing all the way when the floats are up. Refered to as the needle/seat assembly, which could be the culprit, I didn't think of that. I don't know if this is a common item to wear or give you problems, but could be. Also, Honsowetz specifies running 2mm seats. I think mine had 1.7 or something to begin with. Maybe I'm being anal, but I don't know if just a visual check is sufficient to check the floats. I happened to have a spare and swapped it, but I suppose you could remove it and submerse it in water just to make sure it doesn't sink. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 1, 2005 Share Posted June 1, 2005 Anybody else worried about header wrap soaked in gas? The wrap might not be flammable, but the gas is, and now you have a gigantic wick soaked in fuel attached to the hottest part of the car. Not good IMO. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 1, 2005 Share Posted June 1, 2005 Anybody else worried about header wrap soaked in gas? The wrap might not be flammable, but the gas is, and now you have a gigantic wick soaked in fuel attached to the hottest part of the car. Not good IMO. Oh, I'm worried about it allright. That's why I didn't turn it over last night. I'm hoping when I get home it will be evaporated but today is not very warm. I read about the seats I need to run and I'd check what size they are tonight if I could but one of my roomates split beer on my digital mic. When I looked at the ball and needle valve last night they did not look worn, if yoou can even tell by looking. But I'm thinking it was tuned before all this so nothing should have changed. If I need to go richer I could always take out several discs from my mufflers I don't know how dramatic that is. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 1, 2005 Share Posted June 1, 2005 I agree, and it still makes me think that your timing is the culprit. As to the wrap it seems to me that there was a thread about a WRX that burned to the ground as a result of fuel soaked wrap maybe a year or more back. I may be overly cautious on this one but I'd remove the wrap. Quote Link to comment Share on other sites More sharing options...
bjhines Posted June 1, 2005 Share Posted June 1, 2005 ok...engine fires are caused by fuel....fuel needs to get OUTSIDE the carby to get enough air to burn. YOU HAVE A LEAK...or an overflowing carby.... Were the aircleaners soaked with fuel when you had the fire??? This is common and could be the result of sticky floats...overly high fuel pressure, bad inlet needle valves.... If you have "performance" carbys...a common "upgrade" was "Grose jets"...Grose jets HATE gunk and trash in the fuel...They are great...until they see dirt or varnish. A common newbie mistake is cutting new rubber lines and failing to clean the little bits of rubber off the cut ends...another common mistake is removing and reinstalling hoses on BARBED nipples...the sharp edges of the barbs lift little slivers of rubber off the inside of the fuel lines...when you push the hose back on....the slivers are scraped off and end up sticking the inlet jets open. Soo many people miss the little things and screw up their cars.... A good mechanic is not just able to follow assembly manuals...he is also an expert at proper handling and assembly of individual parts...there is a lot more to it than the manuals explain... As far as your car is concerned....A complete fuel system rebuild is MANDITORY!!!!!! You absolutely MUST determine what caused the malfunction. You must also treat the other carbys as if they were exposed or prone to the same problem. Even if you find that the original problem was unique to only one carby....YOU MUST REBUILD ALL OF THE CARBYS NOW that they have been exposed to heat of the fire....All engine parts get hot....but the fire could have heated things far above their failing point. If you brought the car to me to fix...THE FIRST THING I would do is check fuel pressure...It does not need to be more than 1.5 PSI at any time....to ensure flow through undersized fuel lines you may hear of people running as high as 4 PSI...but this is unnecessary with a well thought out fuel delivery system...raising the fuel pressure will not make MORE POWER....It just makes your car burn. In any case...Fire is one of the most painful ways to die....It will also completely destroy your car...do not dick around with this problem...take it to someone who knows how to work on performance carbys on older cars...A Ferrari dealership would be the PERFECT place to find folks who know how to properly work on the siamesed sidedraft types. On occasion.... an improperly set spark advance will cause a backfire into the intake manifold while attempting to start the engine....with the extra fuel pooling/wetting in the manifold at cold startup...a fire can occur.....A carby/manifold fire of this type is easy to extinguish by contiuing to crank over the engine..... It may startle you....but simply continue cranking until it starts....once the engine starts...blip the throttle to draw the flames into the engine...the fire will almost instantly go out... Of course...if your aircleaner is on fire...you better break out the extinguisher...you dont want ashes and bits of paper or foam going into the engine. A little list for you to check.... 1. fuel pressure 2. inlet screens on each carby....functional and in good condition as well. 3. proper handling and assembly of all hoses and fittings....from tank to carbys..This also involves flushing the system into a clear closed container and checking for bits of trash...even one little spec can cause you problems. 4. check condition of fuel filter...look for bits of trash or sludge that may require draining and cleaning the fuel tank. 5. test flow through feed and return lines....a plugged return line can cause overpressure. 6. dissassemble each carby and check condition and operation of float and needle valves...in case you dont know...this involves blowing through a tube attached to the inlet and moving the float until it closes the inlet valve...stopping the flow of your breath though the tube...check float height at the point it actually stops flow...not where it "feels" like it is closed...you must actually test this while blowing air through the inlet....Something like aftermarket "Grose jets" will render the dimensions in the manual useless unless you actually test the jets while blowing air through them. 7. check the condition of the engine mounts and tranny mounts...A bucking engine can literally shake the floats loose in the carbys...although this is more of a problem with off road/all terrain engines. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted June 1, 2005 Share Posted June 1, 2005 With all of the information on Webers on the internet I would do a search and down load the weber manual and other information on the carbs. You can find complete cut sheets and everything you wanted an evan didn't want to know about Webers. Quote Link to comment Share on other sites More sharing options...
preith Posted June 1, 2005 Share Posted June 1, 2005 Soo many people miss the little things and screw up their cars.... A good mechanic is not just able to follow assembly manuals...he is also an expert at proper handling and assembly of individual parts...there is a lot more to it than the manuals explain... If I followed this advice' date=' I'd never be able to afford my car. For the most part, I'm self taught, and am tired of hearing this. There's so many "professionals" that aren't much further ahead than the average guy who's willing to put some time in and learn. As far as your car is concerned....A complete fuel system rebuild is MANDITORY!!!!!! You absolutely MUST determine what caused the malfunction. You must also treat the other carbys as if they were exposed or prone to the same problem. Even if you find that the original problem was unique to only one carby....YOU MUST REBUILD ALL OF THE CARBYS NOW that they have been exposed to heat of the fire....All engine parts get hot....but the fire could have heated things far above their failing point. I agree, partially. I wouldn't think twice about putting on used carbs that I have no idea what condition they're in an haven't had a rebuild, but only Isk knows the serverity of the fire. If they have been rebuilt, and the fire a quick flash, this might be an over reaction. If you brought the car to me to fix...THE FIRST THING I would do is check fuel pressure...It does not need to be more than 1.5 PSI at any time....to ensure flow through undersized fuel lines you may hear of people running as high as 4 PSI...but this is unnecessary with a well thought out fuel delivery system...raising the fuel pressure will not make MORE POWER....It just makes your car burn. The goal is not more power, it's to prevent the carb from curtting out under hard cornering. It is a common among the Datsun racing crowd to run about 4 PSI with a lower float bowl level to compensate for this. Quote Link to comment Share on other sites More sharing options...
bjhines Posted June 1, 2005 Share Posted June 1, 2005 ...hmmm...^^^^ I run my current 240Z at HPDE and TT events once a month...I run autocrosses about once amonth also. I use factory 4 screw Hitachi carbys with no mods... the car puts out 138HP at the wheels..It pulls great all the way to 6500 RPMs...for as long as needed..well over 120MPH...I have absolutely no issues with cut out in corners...Roebling, VIR, CMP, Rockingham...brakes are my biggest issue..not fuel delivery. I used to guess at mixture settings until some dyno runs with an AF meter showed me that the mixture varied GREATLY under different conditions...I installed dual AF meters with twin displays....this took ALL of the mystery out of tuning my car...It runs reliably,cleanly, and powerfully. I must say that a lot of the "advice" I had received over the years about alternate fuel pressure and float levels was a bunch of BS. If you have everything up to factory spec..and tuned properly you will not have cut out problems under any conditions...with Hitachi or the siamesed/triple carbys.... I just went through this with a fella who had the same high RPM cut out you describe...It turns out that the cut out was not related to RPM as much as it was engine load and duration...it just happened to show up around 5k RPM under most circumstances...The problem was fuel flow rate...the steel lines had rusted around the battery tray area...a small pinhole had allowed rust to penetrate inside the line and apparently plugged the hole behind it...rust built up inside the line and almost closed it off...When I performed a pressure test on the lines the rusty area blew out and the problem became evident...once the steel line was replaced the fuel flow was back to normal and factory settings performed wonderfully.... If you want to do yourself a favor...get some time on a dyno..with a working AF meter in the exhaust....It will tell you exactly what is happening under various loads and RPMs. A note about air cleaners....The factory air cleaner is fantastic...there is nothing but noise to be gained by removing it and going with "pop" cleaners...or open element filters....I tried several different common filters and found that none of them made more than a 2 HP difference from stock... The stock filter housing covers and contains the element...it is much less likely to catch fire and burn in that steel box than when it is exposed to the free flowing air in the engine compartment...besides...when the hood is buttoned up and heat builds up...the factory cleaner will draw cooler air in from the front of the car...the "pop" filters just suck hot air off the headers... Triple carbys obviously cannot use the stock air cleaner...but "TWM" makes an airbox to fit them that uses a single cone filter on the snorkel tube.... Apparently Prieth took my comment about professionals the wrong way....I will not vouch for the average mechanic...HS education with some community college does not count as an experienced mechanic... but the manuals assume you know what you are doing..they are not written to cover all the bases for a home tinkerer.... If you have not done it before...get help from someone who has...there are soo many finer points to doing any job correctly that a newbie cannot hope to get it all right the first time...unfortunately...the fuel system is not very forgiving..and it is very dangerous if you do it wrong. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 2, 2005 Share Posted June 2, 2005 Like I said earlier I think timing is the main problem but I started to go through the list of things to do anyways. I bought some hokey little fuel pressure gauge at CSK and on all of my inlets to the carbs it is a hair over 5psi. I'm not confident in the accuracy of this peice o' crap gauge so I think I'm gonna see if I can use anything from my work. So I went on to the fuel filter and a whole bunch of crap was in there. Mainly in the area outside of the filter but there was still some grit inside of the filter area. Bad part is it is reddish brown, DAMN. I'm gonna move to the inlet filters next. I don't like the rebuild idea but depending on how the rest of the inspection goes I might go that route for maintanence sake. I don't have a return line. The assembly of the hoses looked to be good. My carbs do weep a little bit when they are in operation, from what I understand this is normal. Isk Quote Link to comment Share on other sites More sharing options...
bjhines Posted June 2, 2005 Share Posted June 2, 2005 Timing can be tricky if you have changed harmonic balancers from a different year...Some were marked for scales mounted on the left side of the front cover...others were marked on the right. You can check TDC easily enough with a paperclip in the #1 spark plug hole..... just dont get it jammed against the cylinder wall. You can make a new TDC mark with a file or dremel tool. sometimes the keyways in the end of the crankshaft have been "rebuilt"....they are rarely perfect after such a rebuild.... a partially sheared crank Key...or a damaged balancer can also screw up the marks... I have seen balancers that "tore"...the outer weight could twist around... The red stuff is bad...soo is the black stuff...You need to have the tank reconditioned...both colors of sludge will pass through fuel filters easily...right into the carbys....If you just can't wait to have the tank done...there is a drain plug...remove it and replace the copper gasket when you reassemble it....The upper vent lines are easy enough to replace....there is one odd sized section of hose that is very hard to find....there is also a line that passes through the right rear subframe into the rear Q-panel area(vapor tank line) ...use a soft string and a shop vac to pull the string through..attach hose to string and pull it through... As far as fuel return lines go...You should set your system up to use the fuel return system...It maintains constant flow of cooler fuel in the system...the return branch and restrictor should be the last thing in line...after the furthest carby..the individual carby branches should be as short as possible...(less than 6")..to keep the supply of cool refreshed fuel as close to the inlets as possible. You should insulate all of your lines in the engine compartment...feed and return should have fireproof insulation... You should have a heat shield mounted between the carbys and headers...a good heat shield design would also drain leaked fuel away from hot exhaust pipes....your brakes and clutch cylinders could use heat shielding as well. the lack of a fuel return system and heat shielding are not gonna keep the car from running...but when it is pushed to its limits.... they help keep it reliable and consistant.... Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 2, 2005 Share Posted June 2, 2005 here is the gunk that came out. Inside the filter housing Fuel pressurer regulator My fuel lines are all Earl's braided steel line or hard line. The stock lines in and out of the tank have been cut out. Isk Quote Link to comment Share on other sites More sharing options...
preith Posted June 2, 2005 Share Posted June 2, 2005 ...hmmm...^^^^ I run my current 240Z at HPDE and TT events once a month...I run autocrosses about once amonth also. I use factory 4 screw Hitachi carbys with no mods... the car puts out 138HP at the wheels..It pulls great all the way to 6500 RPMs...for as long as needed..well over 120MPH...I have absolutely no issues with cut out in corners...Roebling, VIR, CMP, Rockingham...brakes are my biggest issue..not fuel delivery. You're comparing apples to oranges. The cut out problem is only with webers and mikuni's. Apparently Prieth took my comment about professionals the wrong way....I will not vouch for the average mechanic...HS education with some community college does not count as an experienced mechanic... but the manuals assume you know what you are doing..they are not written to cover all the bases for a home tinkerer.... If you have not done it before...get help from someone who has...there are soo many finer points to doing any job correctly that a newbie cannot hope to get it all right the first time...unfortunately...the fuel system is not very forgiving..and it is very dangerous if you do it wrong. Sorry if I was a little testy. You have a valid point, but personally I've had too many bad experiences when going to a professional. More and more I find that a little patience and learning from my own mistakes will gets me further ahead in the long run. The less I have to depend on outside help the better. With that said, thanks for your input. Quote Link to comment Share on other sites More sharing options...
bjhines Posted June 3, 2005 Share Posted June 3, 2005 For god's sake....Is that a bumble bee on the plate.....Tell me that was not in your filter housing!!!! Mud wasps are skinnier than that bug...but they are a real problem in North Carolina....They will plugg up any hole 1/2" or less with their mud nests...They only way I can store anything in my garage is by oil fogging and bagging every part. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted June 3, 2005 Share Posted June 3, 2005 Yeah it's a bug, it just landed there. I took some carb cleaner to the carbs and realized how much gunk there was. I'm gonna do a rebuild just not right away. I can't find a replacment filter for my car anywhere, not from Russel (housing) or Purulator (filter) Isk Quote Link to comment Share on other sites More sharing options...
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