Couple of questions

[GTSilver944]

I have a few questions:

1. My coupe (1970 2800CS with the stock carbs) is somewhat hard to start. It hasn't been running for the last two years. I have to push the gas pedal down 10-20 times then turn the key and give it a little more gas to get it to start. It idles fine, though the idle is a little high (1,400 rpm). At idle, if you try to give it a little gas the engine will either miss (around 2k rpm) or almost die. When you push the gas pedal to the floor it will rev up as it should. I'm guessing the air fuel ratio is way off. Does the AFR sound like the problem, or is there something else I should be looking for?

2. The clutch has absolutely no feel when depressed and does not work. I'm guessing there is no fluid in the slave cylinder. Where is the slave cylinder located?

3. On the bottom of the carb cover snorkle, there is a large diameter hose that goes to a lower part of the engine. What does this do? Attached to the bottom of the carb cover, there is a smaller rubber hose that attaches to the valve cover. What is this for? Also, should there be a hose connecting the end of the carb cover snorkle to the air inlet pipe in the front right corner of the frame?

4. I just changed the oil on the car. It was black and sludgey (I just bought the car - the nasty oil was the PO's doing). Are there any additives I should add to help clean the gunk out?

Also, it sounds like there is an excessive valve tapping type noise (during the entire two minutes the car has been running so far). I'm not sure what these engines sound like normaly. Any ideas?


Thanks,
Max

 

[x_atlas0]

If the car hadn't been run in 2 years, all the fluids needs to be changed. (diff, engine oil, power steering, gas, coolant, brake, trans, the whole sheebang)

1. That sounds like a carb problem. You may as well rebuild the carbs first, since I imagine fuel stabilizer was not used.

2. The clutch slave cylinder is located on the transmission bellhousing, at about the 7 o'clock position. (if looking at it from the back of the car to the front) The clutch master and slave cylinders ( If I remember right, I haven't had to mess with this in a while) use the brake fluid as the working fluid, so start by checking that.

3. Yes, there should be a hose connecting the intake box to the air inlet pipe in the front clip. I think the hose you are describing is for the crank breathing apparatus. It is to prevent crankcase pressure from building up.

4. I've heard of a few, like Auto RX, which people say helps a lot. Expect to change the oil and filter several times within the next 1000 miles.

A valve adjustment sounds like it is in order, along with a replacement chain tensioner kit. Those combined will help the engine run better and significantly reduce the noise. Also, they are both very cheap jobs.

 

[Honolulu]

my take, the longer version

1. Hard starting after a long sleep is to be expected. Things gunk up. Coupes seem to lose the gas from the carb bowls if left to sit for more than a few days, you have to crank a bit so the pump draws fuel from the tank again.

Cold idle is supposed to 1400 to 1700 rpm. Since it idles fine, I guess the carb is not much out of whack. A stumble when getting off idle, I think, is a result of the idle mix being a little lean. Stomping the pedal from idle give s shot of gas from the accel pump so this can overcome the transition. You may somewhat richen the idle mixture, say 1/2 turn, and see if it makes a difference. Also check ignition timing.

AFR ... you sound like you've been reading too much about fuel injection. See idle mix comment above.

2. Your clutch symptom sounds like either (a) there is no fluid in the combined brake/clutch reservoir, or (b) the hose to the slave cylinder is rotted or blocked, or (c) the slave is bad internally (rubber cup is failed, possibly the bore is pitted.

If (a), you may have no fluid in the reservoir, no brakes and the red brake warning light on the dash should be illuminated.

If (b) hose blocked, disconnect at slave and see if anything comes out by gravity. Warning all the fluid reservoir contents want to flow out, be ready. If hose rotted internally nothing will come out and you'll need to replace hose.

If (c), you need to disassemble slave cylinder and inspect. It's on the left side of the bell housing, jack up car, set on stands, crawl under. There are rebuild kits, but only if your slave cylinder bore is not pitted.

3. The large hose from the bottom of the carb cover snorkle is supposed to go to a mating stug on top the forward exhaust header head shield. It is intended to draw warm air when starting, or when it's cold out.

The hose from the valve cover to bottom of the carb cover routes crankcase blowby into the carbs to be burned, rather than polluting your neighborhood. There should be a "corrugated" large diameter rubber hose about a foot long to the corresponding metal at top right front of the engine compartment to draw cool "outside" air into the engine.

4. There are all sorts of oil additives. B&G makes a good one, also there is Seafoam. I would run either of these for a month or so, with a fill of cheap oil, then change oil again to the good stuff.

For your "tapping" noise as long as it is in the top of the engine, you should adjust the valve tappets. M30 engines (what you have) rarely need this once it has been properly set, but after a long layover you should be checking everything to make sure you know where you are. ALSO while you have the valve cover off, make sure the forward bolt securing the oil spray bar is tight. They are known to come loose, and lack of oil at the front of the cylinder head causes nasty wear on the fron two cam lobes. This will be obvious if it has happened, there are two solutions: live with it or replace the cam.

There is a later type bolt that comes with a little threadlocker on it, which you should implement if yours is/was loose. I'm not saying go buy one, just "implement" that idea. Be sure to well clean the threaded hole first.