AMC Eagle

[MIPS]

And today's challenge: refoam the heater box!




Okay, this was more the other part of the weekend, but things went so sideways I was not able to actually start cutting out the new foam bits until today. Initially I enjoyed how easily the dash moves out of the way and the hater box drops out but as soon as the core was removed it was apparent that small leaks were developing and that it might be a better idea to just replace the core now instead of a few years down the line. My options were one that Saturday afternoon locally for $170, or one from Rock Auto next Monday for $60 shipped. I chose the latter, so the car is all levels of dismantled as I wait for the core to arrive.
While I was doing that I decided to run a fluid check and found that there was fluid layering in the brake reservoir. I think what happened was that while the lid and the mechanics book says to use DOT3, at some point the car had its brake system flushed and refilled with DOT5. So when the car had the brakes done during the rear diff rebuild they topped it up as per book spec and it was just floating on the top layer.




With the system now contaminated (which is VERY bad in this case as it can destroy everything) I had to pump out the reservoir (my hand vacuum pump comes with a nice kit for this so), fill it with new DOT3 and then bleed any remaining DOT 5 out of the master cylinder, lines and brake cylinders by bleeding each wheel and topping up the reservoir as new fluid was pumped in.

[MadMan]

Ew dot5 sucks. Dot 3 or 4 are better, and more available. Plus, really? dot5 in a 1982? Come on. Anyway good thing you noticed.

[MIPS]

[dishdude]

A power passenger seat! Zipties holding the switches on?

[Electronic M]

Let me guess: it is much harder to install than remove.

[bgadow]

Originally Posted by dishdude

A power passenger seat!

Wow, guess AMC really was loading them up with options!

For the last few years I've been noticing a Hornet Sportabout sitting in a driveway. The last time I rode by there it had sprouted a for sale sign. Ah, but the dear Mrs. dislikes wagons...

[MIPS]

Originally Posted by dishdude

A power passenger seat! Zipties holding the switches on?

I've actually not yet inspected that. Supposedly there are two long screws which are in place that secure it to the metal frame of the seat. I'll check on that eventually that and repair it.

It's more frustrating that getting the thing requires lining up the oval defroster plenum port while not scraping the passenger door wall and dumping insulation into the box. Other than that it's a lot less painful than it looks. I got power seats but no Air conditioning, so I get heavy and slow moving seats but at least the dash comes out without a bunch of extra plumbing and a tray package.

[MadMan]

Power seats?

LUXURY!

But no A/C and no power locks/windows. If AMC keeps this shit up, they'll be out of business. Oh wait...

[MIPS]

The configuration for this car is odd. It has power seats, heated rear window, hitch kit and the two-tone horn but no AC, lower tray package, dual map light dome lamp, or either the naturally aspirated or air pump air injection system for emissions control.

The more I look at this car and AMC's history, the more I realize how painfully obvious they were hurting for money. Look at the photos near the beginning of the thread, now look at a '72 model Hornet wagon from a decade earlier.



There's a FEW trim upgrades but otherwise there was pretty much nothing spent on modernizing the frame and body.

[MadMan]

Originally Posted by MIPS

There's a FEW trim upgrades but otherwise there was pretty much nothing spent on modernizing the frame and body.

Probably one of the few things Chrysler kept after acquiring AMC (besides Jeep) was all their engineers. Who had basically been in the business of cost-cutting the whole time they'd worked for AMC.

[MIPS]

Today the last part of the feedback system was replaced. The O2 sensor.


This has almost certainly not been changed in a long, long time. It was completely dead and basically welded into the exhaust manifold. It had to be cut in half before a socket could be put over it and a lot of swearing, pulling and work with an impact driver could get it out. While installing the new sensor the harness side connector also broke off. I didn't have a replacement on hand so for now I crimped on a spade connector and glued the two halves together with RTV. In the future I'll come back and redo it properly once I find the proper replacement one-wire harness plug. The new sensor was reinstalled with a stainless steel plate stamped with the odometer reading and date of installation. In future I need to track down the emissions service light timer form a Jeep and install that.



With the O2 sensor now working the engine warmed up and settled down to a SOLID idle. No more surging and sputtering and I was able to finally set the 500RPM curb as before I could not go below 600 before it would stall at stops.



New problem though: during the carb rebuild we reset a number of adjustments to spec and this in turn nullified the factory set idle jet screw positioning, so the engine runs too lean. The above multimeter should read between .6 and .4v with an oscillation and constant stepper motor action. This will be another upcoming adjustment but otherwise all prerequisites required BEFORE you EVER touch the jet adjustments have been completed so it is now safe to perform this final tweak and not have any variables.

Edited: Wait no, there's one last variable. An exhaust leak can cause a lean condition. Right now the entire length from the manifold to the back is a bit of a disaster or clamps, welds and whistling. It might be advisable to fix that first before proceeding.

[MadMan]

Originally Posted by MIPS

Edited: Wait no, there's one last variable. An exhaust leak can cause a lean condition. Right now the entire length from the manifold to the back is a bit of a disaster or clamps, welds and whistling. It might be advisable to fix that first before proceeding.

Only an exhaust leak up to, and only a little bit past the O2 sensor can cause the sensor to *read* lean. However, I will say that even a pinhole leak can throw off the O2 sensor reading, especially close to it. Also, that any significant exhaust leak will kill the engine power, strange as that sounds, you would normally think a leak would create less backpressure to hinder the engine, but it's kinda the other way around. A big enough leak will create a blockage with its own air currents.

Also, an analog meter might be better for reading the oscillating O2 sensor output, but obviously yours is quite a bit off. But there's also that thing where DVOMs don't necessarily read oscillating DC voltage that well.

Also also, I feel like I suggested replacing the O2 sensor before, but I can't be fucked to go back and look :P

Also also also, nobody ever replaces O2 sensors on pre-OBDII cars, because there's really no way that the driver would be informed of its failure.

[MIPS]

I blew up the gas tank.

The EVAP system has been gradually repaired as when I got the car it didn't work at all and on Saturday I finally replaced the gas cap and the system pressurized normally again.
However in the past at some point after it had failed the tank had developed leaks and was patched with putty and now that everything was under pressure again it promptly began weeping fuel out around the patches. Tank rebuild is $450, but a new OEM tank is $155 plus shipping. Guess what I'm doing.

[MadMan]

Originally Posted by MIPS

Tank rebuild is $450, but a new OEM tank is $155 plus shipping. Guess what I'm doing.

I wouldn't trust a 'rebuild' anyway. It's literally gonna be some drunk bastard taking a mig welder to it.

Here's the thing though (I mean obviously you need a new tank anyway, but) the tank really shouldn't BE under pressure. It should either be vented to atmosphere or under a slight vacuum. Granted, I'm not familiar with the evap system on that particular car - or older cars in general - but a pressurized gas tank is like a bomb, I can't really think of any practical reason for it to be under pressure at any point in time.

[MIPS]

EVAP system on the eagle allows the tank to pressurize and forces vapor through a steel line to the charcoal canister up front. From there it's burned whenever ported vacuum is present (opens the purge valve during acceleration).
Well I guess with the tank out I can verify the vent line isn't restricted. I did check it before when I rebuilt the rollover check valve.