mark105 Posted March 6, 2009 Share Posted March 6, 2009 i have a twin choke down draft carb on my 240k and it is very hesitant to pick up from idle, if you put your foot down too much when its idling it will just kill the car, you have to baby it up to 1000rpm and its fine (car idles at about 850rpm), once above 1000rpm its all good runs fine. If i run choke on all the time a little bit it does improve alot but you dont want to drive every where with the choke on. So dad thought it might be something to do with the pump jet? as it would seem its starving its self trying to pick up from idle but im not sure. Seems weird as it seems to run quite rich (only judging this on fuel consumption and all the soot in the exhaust really tho). Thoughts? Stuff to look at? im not very clued up with carbs. Quote Link to comment Share on other sites More sharing options...
Unclejake Posted March 6, 2009 Share Posted March 6, 2009 Is the carb correct for the motor? It sounds a bit like it is over carbed (too much air flow but not enough airspeed) but it could be as you suggest a split diaphram in the pump circuit or heaps of other things such as the idle mixture is wrong (that should be adjustable). I would be keen for you to take a look at the plugs to get an idea if it is too lean or rich right now and if so fiddle with the idle mixture screw. Engine progression away from idle is hugely influenced by that setting. Is the secondary choke vacuum operated or mechanical? Does the ignition have vacuum advance? Got a picture? Quote Link to comment Share on other sites More sharing options...
sheepers Posted March 6, 2009 Share Posted March 6, 2009 id like to buy "throttle pump is fucked" for 10$. i reckon you'll find the throttle pump is fucked, (as UJ said) then once you fix that you'll find that almost everything else is fucked too (worn throttle shaft seals, float needle not sealing/not there, EVERY setting for the linkages worn/set incorrectly) and it will continue to trouble you for years to come. may i suggest you spend approx 300$ and get your carb professionally rebuilt? i know it sounds like allot of money but you will get that money back in petrol savings in six months. find a place that you can drive to, leave the car there and pick it up latter. Ask them to tune the car once they have done the carb. the place in Auckland to go to is "Carburetor Specialists Ltd, 09 3071773. Its a special feeling when you get in your car at 5.30 in the morning, there is ice on the windshield, and your car starts and idles perfectly, and your car is 35 years old. Live the dream!!!!!!!! sheepers. Quote Link to comment Share on other sites More sharing options...
Hemi Posted March 6, 2009 Share Posted March 6, 2009 id like to buy "throttle pump is fucked" for 10$.i reckon you'll find the throttle pump is fucked, (as UJ said) then once you fix that you'll find that almost everything else is fucked too (worn throttle shaft seals, float needle not sealing/not there, EVERY setting for the linkages worn/set incorrectly) and it will continue to trouble you for years to come. may i suggest you spend approx 300$ and get your carb professionally rebuilt? i know it sounds like allot of money but you will get that money back in petrol savings in six months. find a place that you can drive to, leave the car there and pick it up latter. Ask them to tune the car once they have done the carb. the place in Auckland to go to is "Carburetor Specialists Ltd, 09 3071773. Its a special feeling when you get in your car at 5.30 in the morning, there is ice on the windshield, and your car starts and idles perfectly, and your car is 35 years old. Live the dream!!!!!!!! sheepers. this man speaks the truth ( the starting and idling part) Quote Link to comment Share on other sites More sharing options...
sholdowa Posted March 6, 2009 Share Posted March 6, 2009 I'm with sheepers too. Throttle pump diaphragms always fuck out... Quote Link to comment Share on other sites More sharing options...
BIG-AL Posted March 6, 2009 Share Posted March 6, 2009 Try adjusting your float level it may be low and starving for gas. Al. Quote Link to comment Share on other sites More sharing options...
mark105 Posted March 6, 2009 Author Share Posted March 6, 2009 here is said carb, said carb has been rebuilt by previous owner. i have been over every single jet in this carb and they all correct to factory spec. i have check the float bowl and is all good at idle any ways, sits on the little line in the glass. alot of the seals were replaced also but im unsure about every one. Ignition is vacuum advanced and the second throttle butterfly is vacuum operated also. this is after a little cruise back from the windscreen shop yesturday (yes i has windscreens now ), tiz a shit photo but the electrode? and the earth loop are quite clean and white but the outside thread ring is quite sooty so it looks to be running not awesomely shit. Quote Link to comment Share on other sites More sharing options...
Rusty Posted March 7, 2009 Share Posted March 7, 2009 float level looks a bit low Quote Link to comment Share on other sites More sharing options...
mark105 Posted March 7, 2009 Author Share Posted March 7, 2009 i wonder if thats because its not full??? Quote Link to comment Share on other sites More sharing options...
Unclejake Posted March 9, 2009 Share Posted March 9, 2009 here is said carb, said carb has been rebuilt by previous owner. i have been over every single jet in this carb and they all correct to factory spec. i have check the float bowl and is all good at idle any ways, sits on the little line in the glass. alot of the seals were replaced also but im unsure about every one.Ignition is vacuum advanced and the second throttle butterfly is vacuum operated also. this is after a little cruise back from the windscreen shop yesturday (yes i has windscreens now ), tiz a shit photo but the electrode? and the earth loop are quite clean and white but the outside thread ring is quite sooty so it looks to be running not awesomely shit. Yeah - that plug doesn't look retardedly rich, but it might be a bit rich (hard to say from photo as you already pointed out). I can't offer much more advice sorry but pump diaphram, idle mixture setting, some fuck up with the vacuum advance or worn spindles would be my guesses. It sounds like it is getting a shot of fuel just off idle that the motor can't swallow I assume the fuel isn't stale and that this a new problem\.? I wonder if pulling off the linkage to the pump and driving it around the block will tell you more? It looks like it comes off pretty easily Quote Link to comment Share on other sites More sharing options...
mark105 Posted March 9, 2009 Author Share Posted March 9, 2009 seemed to have fixed it now, played heaps with the idle mixture and needs a lot of choke till it gets quite warm and set the tappets. couldn't believe how shit a so called mechanic i brought the car off who did up the head did the tappets. most were heaps to tight although it was very nice and clean under the rocker cover. seems to be running quite good now. Quote Link to comment Share on other sites More sharing options...
forced Posted March 9, 2009 Share Posted March 9, 2009 seemed to have fixed it now, played heaps with the idle mixture and needs a lot of choke till it gets quite warm and set the tappets. couldn't believe how shit a so called mechanic i brought the car off who did up the head did the tappets. most were heaps to tight although it was very nice and clean under the rocker cover.seems to be running quite good now. That's a trick with old cars. The rockers get slots worn in them where they push on the valve stems. You need a feeler gauge that's narrower than the valve stem otherwise you'll set them too loose. Easy to check the accelerator pump. Just open the throtttle and you'll see fuel squirt out. Don't even need to start it up. Steve Quote Link to comment Share on other sites More sharing options...
Unclejake Posted March 9, 2009 Share Posted March 9, 2009 seemed to have fixed it now, . Fucking choice! Quote Link to comment Share on other sites More sharing options...
mikuni Posted March 9, 2009 Share Posted March 9, 2009 this is after a little cruise back from the windscreen shop yesturday (yes i has windscreens now ), tiz a shit photo but the electrode? and the earth loop are quite clean and white but the outside thread ring is quite sooty so it looks to be running not awesomely shit. Macro = the little button on the camera that looks like a flower. Will focus closer and make it so we can see the plug. Quote Link to comment Share on other sites More sharing options...
cubastreet Posted March 17, 2009 Share Posted March 17, 2009 Beautiful shot of the cement. Quote Link to comment Share on other sites More sharing options...
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