Countach Technical Thread & Questions

I like to start with the simple things first, with the car off, have you tried rotating the fans by hand? Do they turn easily? Old grease sometimes gets gummy and puts a drag on the fan motor. This can cause the fan to run slow which will make the car run hot at idle and it will pull more current causing the fuse to blow. A little oil on the fan motor bearings could fix the system.

Cheers Jim

 

What has be completely baffled is the radiator fans being tied to the fusebox under the glovebox. With Raymonds car (now Joe’s), being a downdraft and mine being fuel injected, the radiator fans and relays are located in the box in the trunk. The schematic for the 25th anniversary cars (which is similar to ours) shows the lower glovebox fusebox, but the fuses are only for the interior climate/defroster fans as well as the A/C condensor fans in the front trunk.

I’ll be real interested to see what you discover! Keep us posted......

Mike

 

Just looking at the 25th wiring schematic again, I do see a relay that controls the disconnecting of the radiator fans..... that relay could be bad and might be causing a fuse to blow. It is relay “R” on the drawing.

Mike
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Mine is a Swiss Downdraft like Joe's, however looking at the heater panel it has the 5000S heater controls on the center console, so maybe that's why? I expect my wiring has more in common with a 5000S than a 25th.

 

Got it. Yes, they changed the controls beginning with Joe Swiss downdraft (GLA12997). My car is about 4 cars later (GLA12002) so it has the same controls.

Mike

 

Guys does anybody know the timing advance for the LP400 engine (dual distributor)?

Thanks!

 

18 degrees static timing. There should be marks on the flywheel, S and D. See page 30 on the lp406 manual. Note I seem to remember the actual marking was different than what the manual said. The key thing is TDC is marked for the number one cylinder. The other two marks are for timing the distributors.

Cheers Jim

 

I started a conversation with you

 

Question on gears not engaging.
Today I tried to get the car out. The car started fine but When I tried to engage the gears, the lever would not go in any gears. Clutch pedal felt as a "2 stages push", harder than usual, then the "2nd stage" feeling softened but still would not engage.
The gears lever engage fine in every position with no difficulties when engine stopped and clutch pedal left to rest.

I experienced this a very few times before then the gear would engage after a few mn with no further issue. This time the issue does not fix itself after 4 to 5mn try and nothing predicted this.

Gears engagement was fine last last month. Any idea of simple things to look for? thks

 

I’d look into the clutch slave cylinder first (sometimes the clutch master cylinder, you have both). Small leak losing pressure.

 

thks. I took a look at my slave clutch cylinder. I noticed that I have a broken screen and a black "plug" floating inside. See pict.
Where can I find a screen like this? and what is this black plug restrictor for? where does it go?
On the pict you can see the 4 small holes on top of that plug.
Finally what is the clutch fluid bleed procedure? I changed the fluid in the reservoir but I am sure there is some other way to bleed this. I should know how to change all the fluids by myself. This should be an easy process and the clutch fluid is the only thing I don't know how to do.
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The screen might be hard, probably nos or used if you can find one. The black float is just that, a float to make it easier to see the fluid level. Neither of these are necessary, just nice. I top the master cylinder off, and loosen the bleeder screw on the clutch slave back in the engine compartment. You can let it drip until a drip comes out steady (keep a rag under to catch fluid) , or better use a mity vac ( https://www.amazon.com/MV8000-Automotive-Tune-up-Brake-Bleeding/dp/B00265M9SS/ref=sr_1_13?keywords=Mityvac+Brake+Bleeder&qid=1693828312&sr=8-13 ) and suck the fluid out. That's just a quick link, you can find them made of metal and different prices. Both versions work fine. If you have not changed the fluid in sometime, I would use the tool, adding fluid in the reservoir ever so often. You won't need to pump the pedal, so no help is needed. On the mity vac, pump up the pressure, release the bleeder screw, when the suction stops, tighten screw & repeat until the bad fluid (looks black) and air bubbles are gone.

 

Thanks! This is very helpful. I got a similar tool for brakes minus the gauge on top, so basically doing the clutch is the same process as brakes. I just need to identify where the bleeder is in the engine bay. Now I can do all my fluids. Saves lots of car down time and money and you know it is done right.
Everytime I get anything done, regardless of simplicity, the car is out for at least a week to a month. What good is it to have the car in a shop instead of your garage? lol.

 

The bleed should be just above the cylinder heads on the rear bulkhead - looks like a brake pipe

 

Possible your clutch disc it stuck to the flywheel.

 

Hi all off anyone have Gallardo repair manual

 

Hi everybody,

I’m hoping somebody on here can give some advice as my Anniversary Countach is spraying fuel out of the tops of the carburetors.

Here’s the background:

The car starts OK, it idles perfectly, it pulls very well and it has plenty of power. It sounds great too.

For a while I’ve been getting a fuel smell, especially after hard acceleration. I thought this was possibly carburetor related so I had them all rebuilt by a reputable Countach specialist. They rebuilt the distributor at the same time. It ran a little smoother afterwards but the fuel smell was still there.

I took it to another good Lamborghini specialist I’ve used many times before. He couldn’t find any leaks in the fuel system, but he could smell fuel. Then noticed after driving the car that under the airbox the tops of the carburetors were wet with fuel. If he revved the car while stationary the problem didn’t seem to happen, but driving out on the road the tops of the carbs were getting wet. So he checked the carbs, checked the float adjustment, tried adjusting the carbs, took one off and investigated it, but nothing seems wrong with the carbs.

So he left the airbox off used a GoPro camera on the side of the engine bay to video the carbs. Everything was normal until he accelerated hard. Under hard acceleration fuel sprays up out of the barrels of all 6 carbs. You can really see it on the video when the car accelerates. But the car still pulls really hard as if there is nothing wrong.

Next he checked the timing. He tells me the timing seems good. He took off a cam cover and did a leak-down test along one bank. He says the inlet valves are leaking around 5%, and one cylinder maybe has a tiny exhaust valve leak. Around 5% doesn’t sound much to me but I’m no expert. Surely if the valves were bad or the timing was bad then the car would run rough? But it runs really well. There are no symptoms except for the fuel spraying out.

His next step is to pull the engine out, take the heads off and investigate the valves. I’d like to avoid this if possible!

What do you guys think? Can something else cause pressure in the carbs and make fuel spray out of the barrels? Are there breather pipes somewhere that could be blocked? Is there a balancing breather pipe between the 2 banks?

Bearing in mind it only seems to spray fuel under hard acceleration, not all the time, is there something else going on here?

Any ideas would be greatly appreciated.

Thanks,

TSS

 

Check the fuel pressure. IIRC, the setting is very low, like 2.5. There is a turn button on the fuel filter that controls this. A cheap fuel pressure gauge will confirm. I don't think this is it, just something I'd verify.

Second, because it's all 6 carbs, the float level on every one is set too high. I realize that's been checked. Were the floats & needles replaced? Use Weber & not off brand parts. In short someone else needs to rebuild the carbs. A fresh set of eyes.

 

Thanks EarlyCat.

My mechanic doesn't think it's fuel pressure either, but I agree with you, I will get him to check it just in case.

The mechanic working on it now is from a different shop to the guy who rebuilt the carbs. I don't know if the floats and needles were replaced by the previous shop, but if they did replace them I'm fairly confident they would have used Weber parts. I'll discuss this with the current mechanic. It might be worth him rebuilding just one carb and seeing if that one stops spraying fuel.

I don't know much about carburetors, but if the floats or needles have a problem and fuel is leaking past, wouldn't it spray fuel all the time rather than just under high load?

 

Normally when a carb leaks, it is due to a float sticking, as in wide open (float position). Sometimes tapping on the side of the carb will unsettle a sticking float, (thats a roadside fix, not a permeant cure). Until you put a load on the engine, the floats just sit there. Once volatility happens in the float bowl, the fuel pump has open reign to fill. I suspect that something centering around the floats, the setting, the needles is the problem.

Wrong needles & 4 psi of fuel pressure will do it.

 

Thanks EarlyCat. That's definitely worth investigating.

 

Are you seeing a small cloud of fuel just above the barrel? It sounds like you are seeing fuel stand-off. At full throttle when the inlet valve closes you can get a pressure reversal that results in a small cloud of fuel hovering over the inlet/ram pipe until the inlet valve opens again. This is not unusual. In period if the inlet was in the air stream racers would simply put a longer air horn on the carb to stop the cloud from being blow away which would alter their mixture settings. Anyway, take a look into fuel standoff and see if that is what you are seeing. If it is fuel stand-off it is normally sucked back into the carb so it is unlikely to be the issue unless there is something else going on. If the stand-off is a cloud mixed with some larger droplets, the droplets are unlikely to get re-ingested. Droplets would suggest there is something incorrect in the carb.

A 5% leakage on the inlet valves will not cause the issue you are seeing. I would not let them pull the engine at this point.

Cheers Jim

 

Thanks Jim.

Yes, I think it is some sort of stand off. However it's worse than just mist, it's more of a misty spray that sprays a foot or more above the barrels.

I think if it was just mist it would get sucked back in like you say and the smell wouldn't be so noticable.

If I can hold of the video I will post it on here.

 

That is definitely more than normal fuel stand-off. I have not come across your issue before. I tend to think the vibrations at full throttle are causing the needle and seats to leak or the fuel to froth up. Things I would look at are: do they make a spring loaded needle for the needle and seat? These types of needle and seats are commonly used in conditions that are subject to a lot of shocks like off roading. The other thing I would look at is lowering the float level a mm or two. The fuel level should be 2 to 3 mm below the spill port in the main jet bore if the level is correct. On a 45 DCOE you can take the wing nut cover off and pull out a main jet. Using a flash light you can use a dial caliper and measure the fuel height relative to the bottom of the spill port. Note it is tricky to get a good measurement. Sometimes you can eyeball it. I’m not sure if you can do that on a down draft. Frankly the fuel level is the most likely issue. Since you have double checked it I wonder if the floats have been replaced and are heavier than the originals. Anyway if you can check the fuel level relative to the spill port it will correct for that issue.

Cheers Jim

 

All good stuff, thank you. I will pass this on to my mechanic. I spoke to him yesterday and he is sure the carbs are fine, but I am going to ask him to check this anyway.