engine and drivetrain Rough running, low idle, and questions

[pisgahlvr]

Hello all, 

 

First of all, let me say that I have done a ton of searching on this forum in past threads. I feel like what I am experiencing is pretty common. I took some pictures and shot some video to share with you in the hopes that maybe you can help me pinpoint what exactly is going on with my car. Perhaps it's an easy fix? 

 

My car is a 1976 base model 02 with a 4spd manual and has approximately 119,000 miles on it. Prior to me owning it, it sat around for about 2 years, but previous to that it ran fine and was a daily driver. 

 

First of all, I have questions about my distributor. Does this look like a fairly new distributor to you guys? Do I still have a "points" setup, or did a previous owner upgrade me to the pertronix setup? 

 

 

I'm assuming the contacts in the distributor cap need to be cleaned up as they have corrosion all over them. What is the best way to go about that? And also, dumb question here, do I need to disconnect electrical power in order to touch them? 

 

 

What are these rings around the shock tower? 

 

 

Is this the electric choke? 

 

 

What is this thing and should I replace it because of that extremely rusty bolt? 

 

 

Also, how do you disassemble and "clean" a carb? Also, that small inline fuel filter, is that the cars actual fuel filter? Or is there another one in another part of the car? Can I take that apart and clean/replace that small filter? 

 

 

As soon as they are finished uploading, I'm going to add some links for some videos I shot of the car running. Thanks in advance! 

 

Here is a video of a cold start. I began by depressing the accelerator several times to get the electric choke to close. The electric choke appears to be operating correctly. 

 

https://vimeo.com/115659687

 

Here is after running for a few minutes. At the end I manually move the throttle linkage with my hand and the engine dies. 

 

https://vimeo.com/115659688

 

And here is after it's warmed up and the choke is fully open. I don't know, but it sounds to me like the idle is way too low. Also when I hit the gas the idle drops down really low and almost dies. 

 

https://vimeo.com/115659689

Edited December 30, 2014 by pisgahlvr

[Chamoix]

- That looks like an original distributor, and it has points, not an electronic ignitor.

- You don't need to disconnect the cap to clean the contacts. Just make sure the ignition is off and use some fine sandpaper.

-The ring on the top of the front struts was originally under the fender to raise the height of the car to meet federal standards for bumper height. Very common to move them to the top to improve the stance of the car.

-Your choke is not electric. It is a water choke. As the coolant temp running through it rises it opens the choke plates.

-The rusty bolt on the water block doesn't hurt anything but the fact that it is rusty probably means something nearby is leaking. You can change it if the appearance bothers you.

- To clean a carb remove it from the car, disassemble, get some carb cleaner from an auto parts store and make sure everything inside is gunk free. Run a fine wire through all of the jets. Make sure the floats are in good shape. Might as well get a rebuild kit with new gaskets. Yours is an original Solex carb. A common upgrade is to replace it with a Webber 32/36. New they are about $200 and you can find them used on this Forum's parts for sale section from time to time. Some folks run two fuel filters, but one where yours is located is more common. They are disposable, so don't bother with trying to clean, just pick up a new one at the parts store.

[esty]

i'd replace the points, plugs & wires, get a new dizzy cap and rotor before i removed the carb...the problem is most likely old, worn ignition parts

[DRedman]

What's that plastic nozzle cap plugging up?  Before I would do anything I would check all vacuum hoses and their respective orifices to make sure hoses are connected and not leaking.  Vacuum is highest at idle and a leak will cause low idle.  It appears that some maintenance is needed on all water/fuel/vacuum hoses as some deterioration and cracking is evident in your pics.   

 

[Mark92131]

That carb is a Weber, Water Choke variety, not the original Solex.  That plastic nozzle is plugging up one of the smog ports on the intake manifold and should be capped off with a rubber nipple to avoid a vacuum leak.  It looks like that some of the smog equipment on your 1976 was removed when the previous owner added the Weber.  If some of the vacuum ports are still open, that could explain the poor running condition.  The distributor is a advance/retard model and should two vacuum ports on the diaphram.  I only see one vacuum line to the distributor and it should be connected directly to the carb, not one of the electro-magnetic valves on the firewall.

 

Also, put a clamp on the inlet side of your fuel pump line, you don't want it popping off and starting an engine fire.

 

Good luck,

 

 

Mark92131

[pisgahlvr]

That carb is a Weber, Water Choke variety, not the original Solex.  That plastic nozzle is plugging up one of the smog ports on the intake manifold and should be capped off with a rubber nipple to avoid a vacuum leak.  It looks like that some of the smog equipment on your 1976 was removed when the previous owner added the Weber.  If some of the vacuum ports are still open, that could explain the poor running condition.  The distributor is a advance/retard model and should two vacuum ports on the diaphram.  I only see one vacuum line to the distributor and it should be connected directly to the carb, not one of the electro-magnetic valves on the firewall.

 

Also, put a clamp on the inlet side of your fuel pump line, you don't want it popping off and starting an engine fire.

 

Good luck,

 

 

Mark92131

 

Do you have a picture available showing what ports are supposed to be plugged? Also where is the nipple located for the second vacuum line coming off of the distributor. also where does that vacuum line plug in on carb manifold? I only see one vacuum line coming off of the distributor. 

[Hans]

I would replace that cracked bit of hose, and the old fabric coated fuel line, plus the items  listed above and the fuel filter and then see how things are working. 

[Mike Self]

One more thing...check the center contact on you distributor cap--it's supposed to be spring loaded so when you push on it, it should move inwards and then pop out when you release it.   Those little carbon contacts have been known to get stuck in their bores.  If it doesn't move, then you'll get inconsistent contact with the rotor, and that can cause misfiring/rough running.

 

mike

[pisgahlvr]

Ok, 

 

Well so far today I have replaced the distributor cap, the rotor, and all 4 spark plugs. 

 

The old plugs look fine, and exactly like they are supposed to. 

 

The engine is still doing the same thing. So at this point I'm leaning towards the problem being with the carb itself or a vacuum leak. The problem is, since I am not familiar with how a weber carb is supposed to be installed in addition to all the emissions gear being removed, I have no idea what is supposed to be plugged or not plugged. The books I have don't really cover this. So if anyone has any pictures of what is supposed to be plugged that would be extremely helpful. Also if anyone has any step by step pictures of how to remove the weber 32/36 water choke carb, I would be most grateful. Including how to disassemble and clean it and reassemble it. 

[GoFaSSter]

What did you do about the points?  Replace? Clean? Are the points properly gapped?  What about the condenser? Did you replace plug wires?  Ohm them out? Before tearing into the carb, you really need to check all the ignition components.

 

EDIT:  Have you checked the timing is correct.  If I retard my timing it runs very close to yours.

Edited December 31, 2014 by GoFaSSter

['76mintgrün'02]

What is this thing and should I replace it because of that extremely rusty bolt?

 

Looking at that photo, it looks like the nut is not tight, which could cause a leak and explain the rusty bolt.  Is that a gap under the nut?

 

I would like to second what GoFaSSter said, thoroughly freshen up the electrical before opening up the carburetor.  I would however give it a washing, as it sits.  A clean carb is a happy carb... even on the outside.  Do replace the fuel lines and pick up some fresh clamps as well.  It doesn't look like there is a clamp on the line where it connects to the carb...  You can take a wrench and make sure the four nuts at the base of the carb are snug.  The gasket can dry out and shrink, causing air leaks.  

 

In the photo of the underside of your distributor cap, I can see cracks in the rubber boot on the end of your spark plug cable.  It makes me think that they are pretty old and I'd suggest replacing them with a set from Kingsborne.  I went with the 8mm set in black and am happy with them.  Bosch wires do not have such a good reputation any more. 

 

Which plugs did you buy?  What did you set the gap to?  Your points look pretty new in the photo, but it would be wise to check the gap.  

 

A dwell meter is a very useful tune up tool, as is a timing light.  Necessary tools, in my opinion.  I like the units that combine both tools in one. 

[pisgahlvr]

What did you do about the points?  Replace? Clean? Are the points properly gapped?  What about the condenser? Did you replace plug wires?  Ohm them out? Before tearing into the carb, you really need to check all the ignition components.

 

EDIT:  Have you checked the timing is correct.  If I retard my timing it runs very close to yours.

 

I didn't look at the points, but they look fairly clean. And I have not checked the timing yet or replaced the plug wires. 

 

Looking at that photo, it looks like the nut is not tight, which could cause a leak and explain the rusty bolt.  Is that a gap under the nut?

 

I would like to second what GoFaSSter said, thoroughly freshen up the electrical before opening up the carburetor.  I would however give it a washing, as it sits.  A clean carb is a happy carb... even on the outside.  Do replace the fuel lines and pick up some fresh clamps as well.  It doesn't look like there is a clamp on the line where it connects to the carb...  You can take a wrench and make sure the four nuts at the base of the carb are snug.  The gasket can dry out and shrink, causing air leaks.  

 

In the photo of the underside of your distributor cap, I can see cracks in the rubber boot on the end of your spark plug cable.  It makes me think that they are pretty old and I'd suggest replacing them with a set from Kingsborne.  I went with the 8mm set in black and am happy with them.  Bosch wires do not have such a good reputation any more. 

 

Which plugs did you buy?  What did you set the gap to?  Your points look pretty new in the photo, but it would be wise to check the gap.  

 

A dwell meter is a very useful tune up tool, as is a timing light.  Necessary tools, in my opinion.  I like the units that combine both tools in one. 

 

I used NGK plugs. I will replace the wires next and purchase a dwell/timing light tool to check that. 

['76mintgrün'02]

While watching your first video (at 42 seconds) I noticed that you are missing two of the four socket head screws that secure the air cleaner adapter to the top of the carb.  I have not installed one of these, but I am guessing these screws might replace the ones that secure the top of the carb...?  In either case you need to install them.  

 

The air cleaner bracket is vibrating to such an extent that it appears to be loose as well.  

 

That plastic caulking cap acting as a plug in the piece of hose on the intake manifold should be replaced with a rubber cap on the metal nipple on the manifold.  If you look under your fuel pump, you will see another nipple with a similar short piece of hose that does not have a plug (caulk cap) in it.  That is a vacuum leak.  Get three rubber caps and seal both of those.  There is another under the base of the carb, which should be capped as well.  Actually there are two there, on the passenger side; the upper should have the vacuum line that goes to the distributor attached to it and the lower one should be capped.

[Buckeye]

Here is link to rebuilding carburator. I recommend that you do not rebuild the Carburator at this time. LEAVE IT ALONE. Others suggested it as well.

http://www.mk3supra.org/topic/561-guide-rebuilding-a-weber-3236-dgav-carb/

As others recommended to you, get your ignition components replaced/cleaned. Get all unused ports capped off first. Get your timing light and dwell meter and set the engine at 25 deg. BTD @ 1400 rpm, but first the dwell must be set at 59 deg. Spec range is 59-64 deg. Closer to low end of the range is better.

[DRedman]

Try this simple vacuum leak test.  Remove all vacuum hoses from any carb  or intake manifold ports. Mark them so you remember where they go.  Plug all the ports with hoses/screws or plastic caps.  Try starting the car and if idle speed increases one of those vacuum port hoses was leaking or the fixture it was going to was defective. If  it still doesn't idle correctly after warming up then spray carb cleaner around the carb base.  If idle increases then you may have a carb gasket leak or carb throttle shaft leak. If still no improvement then spray a little carb cleaner into the carb.  If the idle increases then your carb needs to be cleaned or replaced.