510 Wagon carb issues

[davmoha]

I recently purchased a 72 510 wagon that has the stock carb. The previous owner drove it daily until about 5 months ago. The car will start and idle great but when you push on the gas it bogs down. You either have to go WOT or feather the pedal. Driving it as long as the gas pedal is down as a constant point it runs great. If you let off the gas and push it again it starts to bog down and possibly cut out again. I have changed the fuel filter, plugs, and wires. Have a new cap and rotor coming as well. I bought a carb rebuild kit but figured I would get some advice on possible issues before taking the carb apart. Any ideas or suggestions are appreciated.

 

David M.

[banzai510(hainz)]

look inside the carb. look inside the left barrel of the carb. Now when you cycle the linkage you should see gas squit in the hole from the top. This is the carb accellerator pump.. This enriches the circut while the carb butterfly opens. Maybe the accel pump has a hole in it or the linkgae is stuck in the IN mode.

Think of it as a cup of Soda at McDonalds. You have a full drink with a lid and straw out the top. If you sqeeze the cup the soda will come out the straw. Same operation here

 

I guess you will notice the window in fron of the carb . make sure the fuel is at the line. PS I cant rebuild a stock carb. those carb kits have a million pcs in them. maybe you could just replace the accel pump part w/o taking the whole thing apart.

 

Im sure you didnt need the cap rotor or plugs but make sure the distributor is timmed correctly. Use a timming light. set it about 7-12BTDC. sometimes the distributor bolt can get loose and the dist clocks itself to one side.

 

You say its been sitting for a few months. real question has he FUCKed with it!!!!!!!!

 

 

olddatsuns.com

[davmoha]

There is fuel in the window in the front. I will check to see if it is squirting fuel when I press the throttle when I get home. I know the car will idle fine, had it running for 25 minutes like that. When I first go to press the gas it starts to bog down and I either have to feather the pedal in and out until it runs or press my foot all the way down. The previous owner drove it daily until he bought a new car 4-5 months ago. He hasn't messed with anything under the hood. Although he is very capable of working on the L series motors, he has 3 240Z which are flawlessly maintained. I am just not familiar with the Hitachi carb. Will let you know about the fuel squirting later today.

 

David.

[datzenmike]

Idle circuit has it's own supply of fuel and so does the secondary jet. The primary jet may be partially plugged so this is why it runs WOT but not so well below.

[banzai510(hainz)]

Mike is correct also. I had this happen onece to a weber DGV.

 

maybe cut open the old fuel filter and see if there is alot of rust/dirt in there

[hang_510]

also check the lines, possible clog there as well... esp at the tank.

 

 

 

 

is there a (screen) filter on the carb itself???

[davmoha]

I have finally had some time to work on the car. I can see fuel in the window. I can also see fuel in the carb shooting out when I activate the throttle. I barely see any at idle but the car will idle fine. The issue I am experience is I can drive the car out at a steady speed but when I let off the gas and press it again I have to press it all the way to the floor in order for the car to continue. I also experience the car bogging down when I come to a stop after driving. I can try to feather the peddle during the bogging time but it still cuts off. It will then start back up. I tried adjusting the idle screw between the carb and block and that made it run smoother. I just need to figure out the stalling issue. Is there a way to get the more fuel going in during idle?

[banzai510(hainz)]

ck the timming using a light. should be close to 7-12 deg BTDC

 

was a distributor changed in its RECENT PAST?? oil pump off a tooth? motor reassembled wrong

 

But if you can time it and idles fine I think more of a carb issue.

[davmoha]

Ok will check the timing tonight. I know the previous owner and nothing has been done to the car. He was driving it everyday until he got a new car 5 months ago. After that he only drove it sporadically. I spoke with him and the only he did was change the fuel pump in the last year.

 

David

[banzai510(hainz)]

I assume he put a stock type fuel pump back in.

 

Im thinking its a carb proplem.

 

I worked on Tanas 521 and she had a stock carb. It would squirt gas like it should with the accell pu p but I couldnt figure it out. It would run then soemtimes just do like you said die out. I said Hell with it and got a weber DGV and fixed the proplem.

 

maybe give it a Mexican tune up. Get motor to Rev up almost to max rpm and put a rag over it and hopfuffl it will clear out the jets. Not dirty rag to suck the dirt in (haha)