new fuel filter, rubber fuel lines, fuel pump, gas tank, carb was rebuilt less than a year ago, took the carb apart - cleaned it out and used a rebuild kit on anything that I took apart (if I didn't need to disassemble something to get into clean it I left it alone). The car will start on starter fluid and stay running if I keep my foot on the gas. Doesn't need to be at high rpms (sorry, no tach). I can just be touching the pedal and it stays on but as soon as I take my foot off it stalls as if the gas shuts off. Had a rusty gas tank, but I changed that and the gas is coming out clean. New coils, plugs, wires, dist cap, points. Vacuum lines are all hooked up correctly. Only thing really that's not new is sender unit and fuel sock... could this be the problem or maybe something else. It idled fine once it warmed up before I changed the gas tank. It would also start without starting fluid after it warmed up for the first time of the day. Had a mechanic look at it and he was stumped, but he's mainly a fuel injection dude. It's wierd. any thoughts?
Adjusted the idle screw like crazy with no luck. Same with mixture screw. Put back to stock settings and then messed with it again.
Vacuum leak at carb base...Float set too low or stuck partially shut...crummy fuel pump...(just cause its new dont mean its good) Gas filter isnt on backwards is it??? Turn mixture screws in till seated and open em 2 turns as for the Idle screw turn it till the throttle blades in the carb are just cracked open and go from there.Good luck.
hahah. typed a really long response this morning and then my buddy's comp died. no net at my house yet. I'll try and sum it up. Thanks for the quick response Mavman. How do I test for a vacuum leak at the carb base? Base has a new gasket and nuts are tight..... should I put some permatex on there to seal it? Float level is correct and i tried the screwdriver banging trick (had that problem once already)...any other way to tell if float is sticking? fuel pump worked for two hundred miles already before changing gas tank so I don't think it is that, unless it got hurt by driving those miles with two canister filters in line. It is working like a beast as far as I can tell without doing a compression test. I'm back to just the one new fuel filter that screws directly into the carb - Carter RBS - so it can't be backwards and it's brand new. Already tried that with regards to the idle and mixture screws, then changed them all sorts of ways and back again with no luck. This is perplexing (haha... college vocab at work) and doesn't make much sense to me. was working fine before changing the gas tank except that my fuel filters kept getting clogged and stopping the car from running. I did have to fabricate a way for the vent to attach to the top of my new tank (switched from a seventy-one tank to a 77) but I can't imagine that could cause this problem. It leaves me to think that it is the sender unit because that is the only thing I haven't changed and checked, but I don't know why that would cause THIS problem... I guess I could compression test my fuel pump when I track down a tester but I don't think that's the problem. anyone got any other ideas or tricks while I track down a tester??... Meeting with the mechanic tonight to brainstorm but he's pretty stumped too.
Spray water around the base of the carb.If the engine stumbles...You found your culprit.If the pickup sock has fallen off the tube in the tank and your fuel level is really low...That would cause a stall while accelerating/stopping or turning a corner since the length of the pickup is now shorter W/O the screen on it.If the tank is not venting properly,you caould have a fuel starvation problem(the pump will actually create negative pressure in the tank) this will act like vaporlock and stall the car due to lack of fuel.Let it run and quit...Then pull the gas cap off...If you hear a strong whoosh/sucking sound...tank aint venting.Fix that and see what happens.Good luck!
word. it is getting dark here now. I will definitely try those things in the light and get back to u. The sock had fallen off in the old tank... I fished it out, cleaned it with carb cleaner and then used two hose clamps to put it back on (auto stores wouldn't sell just the sock)... couldn't get a new filter for the sender unit as well, so that got cleaned with carb cleaner and put back on the same way it came off... Tank only has five gallons of gas in it. I'll get back to you when I try those tests. thanks man.
could it be something having to do with my fast idle screw? I feel like it's not sitting correctly on the cam.... it actually doesn't sit on the cam at all once it get's started.
fast idle screw only comes into play when the choke is on try bumping the idle up just a bit until you can get it to idle
this s mechanical pump correct a small pin hole in the diaphram could cause a low rpm drop in fuel pressure to nothing the fuel filter you cleaned and put back on can you by pass it to make sure it isnt the problem if you already have another inline filter and new tank this wont hurt anything espeically to diagonse the problem and make sure you hose clamps on the sock arent to tight were there restricting flow basically the mechanical fuel pump also works of gravity a bit to supply fuel to the engine so we know fuel is getting to it or it wouldnt run at all, we also know when the gas pedal is pushed it will run now this could be do to improper assembley of the carb or the above mentions hole in the pumps diaphram if you can get a known good fule pump and throw on there to make sure thats not it past all that i would assume the carb has issues
my other suggestion to anyone running a mechanical pump is to convert to a good quality electric as well but you need find this problem first then i would recomend that
it's wierd. when I take my foot off the gas it's like the fuel just stops. I can't get the rpm's down to where it used to idle at either. It shuts off at higher rpm's than that (no tach). Did the water test around the base of the carb and it wasn't that. No vacuum noise when I open the gas cap. when I'm holding the gas just at the point before it shuts off the engine pulses if that helps... can't figure this out. No problems with this before changing the gas tank. so confused, been searching the forum like crazy with no luck.
So what your saying is the engine will run as long as you keep a foot on the gas and keep the revs up??? When you dismanteled the carb to re-build it...Did you remove the throttle blade from the shaft??? (this is generally a no no).It sounds like the idle circuit in the carb is plugged up.You need to flush and blow out the passage where the mixture screw goes and then see if it will idle.You may have to pull the carb apart again to check it out/clean it thuroghly.Good luck!!
no, I left the throttle plate on. only took apart what I needed to get in and clean it. Didn't think of taking the screws out and cleaning out where they go in. I will try that in the morning. thanks.
k. did that. got another new fuel filter just in case. only 3 bucks. still no luck. was able to start it a couple of times without using starter fluid after it was warmed up.... i guess that's a good sign? new symptom is that it sounded like my gas was boiling in the carb after it stalls out. don't know if that's new or if I just didn't notice it before. this is making me think it's a vacuum issue or something having to do with that cam my fast idle screw rests on (don't know why that cam is stuck in my mind). Tempted to buy another carb and just upgrade to the 2bbl to be sure but i'd rather not.
