lpraun

Problems solved. Basically it was incorrect float level setting, that was the cause of the problem. With competent guidance and advice from Bruce Palmer from ztherapy and a little time in the garage, the car now drives like a dream. It is now again my favorite car:love:

Yep – I think I have to contact Bruce – I’m sure he can lead me in the right direction. Chris, I did not bring the car to Copenhagen – I need a place to park the car and that needs some planning!

In desperation and because I ran out of ideas, I changed back to the old carburetors – and it drove beautifully. It felt rock solid all the way up to 6500 – and beyond! So this IS a carburetor issue – and I’m empty for ideas!

Okay – float level set at 14mm exactly and fuel mixture setting is set so, when I lift the piston in one of the carburetors using the little pin on the underside, the rpm goes down and the idle get rough. Sparkplugs etc. cleaned and timing set to 15 deg BTDC. The car will rev all the way to redline when standing still – and it seems like it gets worse up through the gears – the engine sounds troubled – it’s like a deep rumbling sound while the willingness to increase the engine rpm goes down. What does it sounds like when the car pings – I know it is difficult to describe a sound, but give it a try!

Okay – a quick update! This morning I switched the float cover from the old carburetors to the new on the car – this did little to nothing on fixing my problem. Then after a little bit of thinking and a cup of coffee I needed something else to do than messing around with the carburetors and decided to look into spark delivery and timing – even though I cleaned the sparkplugs – that where quite black (rich mixture??) – the points in the distributer cap and the distributer pointy thing that goes round and round inside the distributer. I left the timing at 10 deg BTDC. And that helped to a degree – now it will rev to 5000-6000 rpm but it sounds sick and without a lot of power. When I started it up the idle settled on 1000 rpm even though I had tuned to around 600 before I cleaned the sparkplugs etc.

Hi Chris – long time no hear! I’m at my parents place on Fyn, but maybe I will bring The Datsun to Copenhagen sometime during May if I can make the car run properly – then we can meet up and… you know – look at it! I’m positive that the pistons is not sticking – they move freely but it take a lot of force like if I there is a very heavy grade oil in the damping thing – but I have used standard ATF. Well – it’s getting late and I’m off to bed. I will adjust the float level tomorrow and let you know how it goes!

Okay – the float level then! The 14 mm distance you mention – is that from the underside of the “roof” of the lid or is that from the underside of the edge of the lid that protrude about 3 mm further down? I hope it make sense.

Last year I swopped to a later z-car electronic ignition distributer with the E12-80 ignition module, so points and vacuum advance is not an issue. The linkage is assembled correct. It idles fine and starts with little choke and pulls fine until about 4000 rpm. The fuel filter is also quite new and I had no problem with it before. Everything was working fine (I know it sounds stupid) before I switched to the new carburetors! Therefore am I fairly convinced that this is a problem with the setting of the carburetors – the question is what! Could this be a classic problem regarding incorrect float level setting – the new carburetors is right out of the box from ztherapy so I trusted the level setting to be correct?

Hi, as the headline states my car will not rev past approx. 4000 rpm. My car is a 1973 240z converted to 3-screw SU carburetors (long time ago) and electronic ignition (recently) no emission control – everything is the original setup. The carburetors are worn with air- and fuel leaks etc. – bottom line is that they were in pretty bad shape! Despite of that the car ran quite well – revving all the way to 7000 rpm. Anyway I decided to fight the recession by spending some money on a refurbished set from ztherapy – and I was very happy when they arrived this week – they look great! Now I have switched to the new set (4-screw) and tuned them according to my workshop manuals and numerous write-ups on this forum and elsewhere on the net – which basically tell the same. Now – does anybody have any idea about what could be wrong – the ONY thing I have done is to switch over from the old to the new carburetors. I mean – these SU carburetors is freaking simple – float level, fuel mixture, idle, fast idle – make sure they are balanced – what else is there? What could be my problem – please help! I have searched, found and read a lot of other threads about the same problem but have not been able to solve the problem. Another thing I have noted is that the pistons in the carburetors is quite difficult to push up – I am using ATF in the dampers. Also, they do not go up very high when I rev the engine – only around 5 to 10 mm. Help me! Lars Peter

Yeah.. I have driven the Lamborghini Miura – in my dreams A list like this is always debatable and it will never be final – I don’t know if you have the Citroen Berlingo in the US - I hope not. See picture below. But this car should be recognized as the first car to nonsurgically remove the balls of any male owner!

Now when the snow is gone, the temperature in the garage have risen above 5° Celsius (41° F) and the cover is removed from the Datsun – it’s time to get it ready for a new season. During the winter I have collected some spare parts and upgrades to prepare the car for the summer! The list to do is as follows: • Install original looking mylar sunshade – many thanks to Arne for making this possible! • Replace the old rusty gas tank with an, equally old, but rust free tank – including new hoses. • Install the passenger side rear speaker – in order to eliminate the sound coming from the driver side speaker. • Repair a dent in the driver side door and line it up properly with the body. • Install rear sway bar. • Repair the broken driver side seat backrest – or replace the seat. • And as the icing on the cake – I cannot wait to install my newly purchased ztherapy carburettors. This concludes the cheep or already purchased repairs or upgrades for this spring. On the longer run and if the funds are available I would like to install the following to my car: • 5-speed gearbox • BRE style front spoiler, and maybe the rear spoiler – I cannot decide if I should go for the sleek look without the rear spoiler or the mini super car look with the rear spoiler – I like them both! On a hole other note I would like to show off my “new” baby. Last fall I bought this 1991 BMW E30 325iX Touring to replace my old faithful Morris 1000 Super as my daily driver. To expect an improvement over my Morris is obvious, but way this, 19 year old, machine drives is fantastic, even compared to modern cars – especially fun is the 4-wheel drive system in the snow! The body is rust free and the car is equipped with most of the bells and whistles of the time. Well, this ended up being much longer that intended – bear with me. Have a nice and productive Easter in the garage!

Okay guys – did what You sad, warmed up the engine and when I returned home it had a hint if the sound, when I manipulated the throttle. I tried to disconnect different hoses to the emission control systems with no result. I then took of the air cleaner box, and then the sound became much louder and I was able to locate the sound to the idle compensator positioned on the air box back plate. I disconnected the little hose hidden away inside the jungle of other hoses in order to see if I was right – and I was:) It’s nice to know nothing serious is wrong with the engine – now only my pride is subjected to excessive wear when I idle at a stoplight:embarrass: Thank You very much for the valued input. The next question is then how do I fix this or how do I test the idle compensator to se if it works properly – the sound from the idle compositor might still just be a symptom of something else wrong!

The fan clutch is good, and I installed a new water pump a couple of months ago. It sounds like the sounds comes from somewhere around the carburettors and the heap of emission control tubes. The car is not overheating, and I just changed oil and the level and pressure is good. My big worry is if somehow there is a problem with the lubrication of the camshaft or any other mechanical component, resulting in excessive wear or failure.

OK – This is the situation. The car starts fine with full choke and warms up nicely – choke gradually off and after 5 minutes it idles at about 700 rpm with no choke. After a good drive, when it returns to idle it makes a horrible wining sound and will stall or run at very low rpm. If the engine stops and I try to start it again it is very difficult to start. Choke does not help and if it starts it runs at very low rpm – and eventually stalls. I have made a video of the engine making the sound. I am the one who rev the engine in order for it not to stall – as it does in the end of the video. It’s a 73 car with 3-screw round top SU carbs. With all 73 emission control systems still installed. Does anybody have any idea of what is wrong and what I can do to fix it?

I ended up paying the DKK 13.650 (approx $2.350) because I already had a formal quote from the authorities I evaded the extra fuel tax! I can come by Thursday around 13 o’clock with the radio if you are home.