MDchanic

Hello, all.

I just bought this '73 88 convertible, just to drive, not to restore...

So I'm going over things to see what the previous owner(s) screwed up, and I figure out that the motor is a 260 from the late '70's / early '80's (I didn't even know they made a 260).
I'm trying to ID it as best I can, but it's got no numbers stamped on the little pad on the left side behind the PS pump, just a blank face.
The heads are 2A, which makes it a '76 to '81 260.
The block casting number is 557751 - 2H.

This motor has:

• a DualJet carb (brand-new, it looks like),
• on the correct intake manifold (no Quad secondary bores to use),
• EGR,
• a single 3-port temperature vacuum switch
  (in the left-hand-most hole, to the Left of the idiot light sensor),
• a 2-port disc, colored yellow and black, beneath a steel clip beside the oil fill neck on top of the timing chain case, which should be a low-temperature switch for the EGR,
• a 3-port, free-floating white plastic valve with a round aluminum top and a green button on the bottom,
• Evap., PCV, Trans. modulator line, Distributor vacuum advance, power brake take-off, and all that good stuff.

It also runs well, is smooth, doesn't smoke, and makes no bad noises (aside from a small exhaust manifold gasket leak on the Left, which I should be able to fix by replacing the gasket).

It is timed dead-on at 14°, which is stock for a '73, not sure what this should be.

HOWEVER, it does not like it when you press on the gas pedal -
it wants to stall every time, unless you sneak up on it.

In checking things out, I have discovered that both the EGR and the Vacuum advance diaphragms are holed, and both are nothing more than vacuum leaks. I have eliminated them, and all the other plumbing, but the problem is the same (of course, I've never seen it with a working vacuum advance).

So my questions are:

• The NAPA VC-1855 or Standard VC-225 (code AS7) are the vacuum advances that seem to be listed for this motor (remember, I don't really know what it came out of).
  Advance should start at 3-5" Hg with these and run to 15°@10-12" Hg.
  Does anybody know whether the advance on this engine is designed to run with full port vacuum, or with reduced port vacuum, through a reducer, due to the fact that it's also used by the EGR?
  And if it needs a reducer, does anyone know if either of these emissions thingies I have pictured is the one, and how it should be connected?
• Does anyone know the right initial idle advance setting for this motor?
  Is 14°BTDC correct?
• Does anyone know the maximum advance of the centrifugal unit on this motor, so I can be sure it's got the right distributor installed?
• Any tips on removing the exhaust manifold bolts?
  I plan to use 50/50 ATF/Acetone on them first.

Note that I have no intention of fixing the EGR, though I will put a new gasket on it, and maybe a drop of silicone sealant just to be sure it's dead.

Note also that I am not trying to rekindle a lengthy discussion of ported vs manifold vacuum for the advance can - I plan to try both and use whatever feels best.

Thanks for your help, and sorry for the long post!

- Eric

rocketraider

God help. Who put a weenie engine like a 260 in a car that heavy?

A faulty vac advance will cause hesitation like you describe. Any parts store piece you get now is going to be generic and not tailored to the engine.

Vacuum can plumbing on these engines is convoluted at best. No telling what route the vacuum supply takes before it gets to the diaphram. I'll have to look thru my late-70s stuff at home.

MDchanic

Someone in a big hurry to sell it, I'd bet.
But whoever it was was a decent number of years ago, based on the thickness of the grease layer. I'm sure he'd be amazed that the car had avoided the crusher this long.
And poor power doesn't matter that much to me, since I'm not towing anything, and I'm no longer a teenager.
Also, having owned a couple of 455's, I have a gut appreciation of the meaning of "six miles a gallon."
And it was cheap.


Thanks! I appreciate it.

- Eric