Bouyo

I've recently bought an '83 LM and, after spending a good number of hours under the hood using the FAQ page, I'm running out of ideas on where to go next. I'm also relatively inexperienced at car repairs although have spent some time on old Land Rovers - they're like Wankels right?

Here's a brief bit of info on the car and what I've done so far:

Engine is stock 12A with rats nest. Currently at ~140k. Carb is stock Nikki.
I bought the car from someone who'd just rebuilt the carb, said there was a vac leak after reinstalling it and that he didn't have time etc

Ok, so I go to looking the carb over. I noticed that the primaries weren't closing completely with the idle adjust screw -> adjusted the throttle cable forward and the idle came down (must have been high from hanging open on the cable).

Take the car down the road and the power bogs badly at about 4k -> I have an idea the secondaries aren't opening, check the secondary throttle assy and sure enough, they're seized. Unstick them and take the car back out, no change. Check the secondary diaphragm box - seems fine. Open the secondaries by hand and there's fuel coming out the jets into both venturi.

Read up on carb troubleshooting - thanks Sterling - and see that my fuel bowls are way overfilled. This, combined with the secondary assy that needs serious unsticking, prompts me to pull the carb.

Rebuild kit in hand I take the Nikki apart. Discover the floats are way way off, one needle/seat is sticking badly, and the Main Body/Throttle Body gasket is put on back to front (secondary vac channel didn't have a hope of functioning properly) -> Adjusted the floats, replaced needles and reassembled the carb with gaskets in correct orientation.

This evening I turned the key, started up fine, both fuel bowls perfectly filled to the line. Took her down the road, secondaries opening now but as soon as the engine builds to 5k I have a serious whine coming through to the cabin. On top of this the engine DOES NOT want to rev past 5500. Get back to home and rev the engine by hand with the hood up - can't see anything, or really hear anything over the noise of the engine. Get into the cabin and do the same with the pedal - now the whine is very audible.

I don't know if the loss of power and the whine are connected but I'd really some advice on the next step to take. I'm thinking maybe the engine is fuel starved at these high rpms, or the secondaries aren't opening enough. Neither of these problems would cause a whine though!

Any help that can be offered to a newbie like me is greatly appreciated, and if you live in Western Mass then you're welcome to come check her out

Humbly yours,

Joe Stearn

mazdaverx713b

iTrader: (91)

Rev the engine by hand and listen for the whine. More than likely there is a vacuum issue. Can you post pictures of your engine bay with the air cleaner housing removed? You were smart to remove and rebuild the carb. If someone gets in there that doesn't know what they're doing or doesn't know how to follow a service manual then a lot of damage can be done.

Bouyo

Ok, I've just performed a second smoke test on the carb/inlet in an attempt to find leaks. The first test I did was after I bought the car but was totally inconclusive as I didn't block things off properly (man that's a lot of smoke coming out the carb, so much I can't see much else).

This time I used a rubber glove/duct tape effort to seal the airhorn as best I could. Plumbed smoke into the secondary anti-afterburn vac line ...

As best I can tell I have 5 leaks, 2 of which are obvious direct leaks that I should fix right away. The other 3 I'm not really sure about. Here are the five leaks I found:

1. Cracked hose @ inlet manifold to #2 Anti-Afterburn valve
- I'm assuming this is a classic place for a cracked hose

2. AVC housing face plate
- Little leak off bottom (I'll replace the gasket I guess)

3. #2 Choke diaphragm
- Not sure about this one: there's a 1mm drilled hole on the underside of the diaphragm housing that was spewing smoke - should this be there? I can't think why it would but the hole is obviously drilled.

4. Blue (relief) solenoid valve air filter
- Steady little stream of smoke: this can't be right can it?

5. Air pump housing facing engine
- This is a strange one. It looks like there's a screw missing and there was smoke coming out of the housing, but only when I put smoke down through from the air cleaner hose. Even if the air pump was drawing through its housing, this isn't part of the vac system right? It should just go to the exhaust I think. I took a pic of it anyway rather than pull the pump off, incase one of you can shed some light on correct-looking airpumps!


Also I've included a quick shot with the airfilter off as was requested. Not sure how much info that will give anyone but there it is.

I really appreciate any help that can be given. Maybe some day I'll be able to return the favour!

Thanks,

- Joe

KansasCityREPU

iTrader: (9)

The air pump is suppose to be open there. That's normal.