My '85 MGM, "Maisa"

[Arquemann]

Did you give the new joints a whack with the hammer to set them after the clips went in? I seem to have forgotten that on the Continental and the front joint was tight in one direction. A couple love taps got it nicely un-bound and almost completely eliminated a vibration problem that it had at speed.

Yea I did, all new joints felt smooth and free after assembly and greasing.

The vibration I'm having is kind of a side-to-side wobble, which doesn't feel too awful, but I notice it well from the passenger seat really wobbling side to side if empty.
I can feel it the most around 70-80kmh, and it mostly disappears going above 90kmh.

[Arquemann]

Upon driving more after recent repairs, I have a few notes:

- It seems like the new U-joints didn't do quite nothing. When not trying to over-analyze the ride quality and just driving along, the car does seem to ride smoother. The vibration/wobble that I tried to get rid of seems more distinct, so it could be there's no more overlapping vibrations from different sources.

- The Fairchild 1001 window channel weatherstripping might not be any quieter than the Metro WC3396, but the wind noise is softer and more pleasant on the ears.

- The random O-ring I stuffed around the axle of the driver's wiper pivot axle might actually be doing something, I drove home in heavy-ish rain and around 80km/h the wiper blade did not contact the windshield trim and didn't get too close either.

[sly]

If a tire is out of round this can happen. If the drum brake has a dent to go on the hub in one specific place and it's not mounted that way it would cause the wheel to get mounted at an angle and cause this. My trailer (81 F150) has this issue. Drums only go on in one position. Any other position sets an angle to the wheel.

[Arquemann]

Yesterday I got the carb off and threads repaired, put it back together with a few new seals. Today I slapped the carb back on the engine, fired right up with no leaks, but a weird problem that's got me totally stumped:

The throttle is sticky, but only when running. The throttle linkages move nice and free when the engine is off.

[DerekTheGreat]

Hmm. Guessing the bind sets in as the engine moves a bit when the throttle is applied. Something to look into?

[Arquemann]

Hmm. Guessing the bind sets in as the engine moves a bit when the throttle is applied. Something to look into?

Dunno what you mean by that. The throttle becomes significantly stiffer to move to either direction, that's with all the throttle cables and other linkages off. The factory return spring isn't strong enough to pull it back to idle (which has been fine for the last 2 years).

But that's only when the engine is running. Engine off everything is as normal.

I'm guessing it could have something to do with vacuum causing a bind in the throttle blades somehow. But I didn't even touch any of that stuff when I had the carb off.

[sly]

That is a weird issue. I'd shoot some penetrating lube on the throttle shaft and see if that helps to lube to shaft in the throttle plate. Other than that, I can only think that something isn't lined up quite right after reassembly.

[DerekTheGreat]

Oh, didn't realize you meant without the cable/shaft connected. I assumed that stuff might be causing something to bind. In that case, yeah maybe the engine pulling at the throttle blades or something got dinked in reassembly like sly said.

[Arquemann]

Things got better and worse...

I found 2 problems:
- End of primary throttle shaft was rubbing slightly on the choke housing
- Baseplate is warped as shit

I ditched the electric choke mechanism, cleaned the throttle plates and bores thoroughly (not that they were particularly dirty) and squirted some PTFE lube around the throttle shafts, maybe it'll do something. (I found out why the electric choke was a total POS; the high idle cam is quite worn so the screw would easily slip off the cam and that's why it wouldn't engage reliably)

Plopped the carb back on and the throttle didn't seem to be sticking anymore, which is great! But now I had a big vacuum leak, it ran lean and wouldn't idle.
I replaced the thick insulator gasket with a new one (Edelbrock 9266), put it all back together, bolted down crisscross and torqued to spec, still a sizeable vacuum leak right under the carb...

So I decided to do a no-no and I siliconed the gasket to the intake and the carb.
Tomorrow once the RTV cures we get to find out if this absolute travesty works out, or do I get to buy a new base plate for the carb.

I'd love to replace this hunk of junk, but I'd be throwing all my tuning efforts away and new carbs are stupid expensive.


EDIT: To add, I have no idea when or how the carb baseplate has gotten so warped. I haven't had sealing issues before and I've always used a torque wrench to install the carb.

[kishy]

EDIT: To add, I have no idea when or how the carb baseplate has gotten so warped. I haven't had sealing issues before and I've always used a torque wrench to install the carb.

And then there's me, who probably does those things up to 80ft-lbs...whoops.

[Arquemann]

I let the rtv silicone cure overnight and today I fired her up. Starts and idles better, wideband gauge would indicate the afr to be around the same as usual, so if there's still a leak, it's not too big.
There's zero sticking in the linkages anymore, don't really know what I did to fix that, if anything.

Also it doesn't leak fuel anymore either, which was kinda the whole point, initially.

[sly]

Victory?

[gadget73]

I have spent too much time using a file or a piece of sandpaper on a flat surface because someone used all the torks to tighten a mushy aluminum part to the point where it absolutely would not seal.

[Arquemann]

Took a drive to make sure the TV adjustment is still alright and it is pretty good. Since I ditched the crappy carb mounted cable bracket I wasn't too worried about losing adjustment.

The throttle does have an itty bit of gumminess right above idle, but it wasn't really noticeable when driving. Dunno what I'd do about it, but I'll chock that up to the warped baseplate. Might try another return spring, but those make the pedal heavier, which I don't like at all. Maybe I'll put a spacer on the captive spring around the throttle cable?

A baseplate swap probably wouldn't hurt, but that'll be a thing for the future (unless this thing shits the bed again).
Or I could yeet the Holley and Lokar cable in the bin, and buy a reman 2150 and a 2bbl adapter

[DerekTheGreat]

I didn't realize how stiff my '85's linkage was until I drove one of these boxes with that new-fangled SEFI system on it. It was one of those things that once you're aware of it, you can't become unaware. It became such an annoyance that I tried all kinds of things to make it better. Futile efforts. Sure, there was some improvement, but I was elated when I replaced it with my '88. By comparison, it's not heavy at all.