1982 w123 euro model 250- VACUUM / TRANNY weirdness

[blankenship]

hey all-
so, i bought this baby (the 1982 euro model 250) a couple weeks ago, and am trying to diagnose some stuff. there's some weirdnesses with starting, shifting, and running that i'm guessing (?) may be vacuum related, and i could really use some help. (Note the attached photo of current vacuum routing).

FYI, she's got the 123.921 inline 6 cylinder motor, a 4A1 carb, an automatic transmission, and 261k on the clock (no idea about history).

Issues:

1) When shifting into Drive or Reverse there's a good 4-5 second delay before she'll engage. (transmission fluid level's full and bright red).

2) She will not start when in Park (just clicks). She'll start great in Neutral.

3) She'll do a weird short engine rev in 2nd gear sometimes.

4) Upon accelleration, she'll do a big hesitation/stumble before engine rev.

There are a few missing vac lines, and I have NO IDEA where they are meant to go. Please see photo! (In the green square, there's a 'capped' switch i'm guessing is a thermo time switch(?) that I have no idea of the proper routing. In the blue square, there's a couple lines heading into the firewall which don't have mates.)

If anyone's got advice, or a diagram, or a photo of the routing on their own 250 or similar, I'd sure love to hear!

[david s poole]

don't worry about one with green square just a vacuum temp sensor during epa mods.the check valve with the yellow vac line is for door locks and vacuum reservoir.i don't see vac line going to trans ?

[blankenship]

hey david-

that line in the photo (going up to the manifold) joins a fitting on the manifold with a line heading straight back over the top of the tranny. i've pulled vacuum on both lines and they DO hold vacuum. hmmm.

where's that door lock/check valve/reservoir set coming out of the firewall supposed to draw it's vacuum from? could it be affecting my problem, or no?

i'm adding another photo showing more of the compartment, as there's also a line missing from the bottom of the fuel pump...

ideas?

[david s poole]

i think that if you run a good clean intake manifold vac line to the modulator on the trans things should improve considerably.

[blankenship]

thanks david- i'll swap that modulator line and hope for an effect.

meanwhile, anybody out there got answers for the vacuum routing and other symptoms?

[blankenship]

well, i swapped the modulator vacuum line and connectors with no effect: still get a 3-4 second pause when shifting into Drive. any other ideas? i put the vacuum gauge on the on the modulator/manifold port, and it's pulling 15-16 in. hg at idle and holds vacuum the other direction (at the modulator.) does all that that sound right?

also, this stumble at acceleration's gettin' dangerous. the light turns green, i push on the gas, and the engine goes quiet while i sit still. i let off the gas, or sometimes even stomp on it, and things even out or she revs up and takes off... ideas?

oh, and what's this port in the photo i'm attaching? (it's on the manifold right behind the carb. doesn't appear to be sucking air or anything while car idles). what is it and what should be connected there?

[david s poole]

that is another one of the temp vac valves that was used to pass thru epa test.don't worry about it.hesitation sounds like something wrong with accelerator pump.it shouls spray fuel as soon as the linkage is moved.have you checked the bushings on the trans shift rod under the car?

[blankenship]

i'm lost on this thing! anybody got guidance for some of the continuing questions?

1. there's two vacuum ports on the bottom of the fuel pump, as shown here
and here
.

one of them was sucking air, so i capped it, but with no change in performance. do you know what it's supposed to be attached to?

2. do you have any idea where the door lock vacuum stuff shown here: is supposed to draw it's vacuum from?

3. i greased all the accelerator linkages, and noticed that one of them, shown here:
has a wierd thing where one end (in the pink square) moves about 3/4" in the shaft (allowing for some slack) upon acceleration. is that normal, or is it broken?

4. how do you check an accelerator pump?

[david s poole]

i think the ports below that valve are for fuel shut-off.the door lock stuff needs just a good vacuum supply,but they prob leak so be aware.that slack is supposed to be there as freeplay.if you look down in the carb primaries [small throats] and blip the linkage with engine off you should see fuel squirt from acc jets down the bore.see how this works and adjust so that small movement of linkage begins to squirt.

[blankenship]

hey david + all:

well, i checked the accelerator pump by looking down the carbs, and when i moved the linkage, both sides seemed to squirt pretty immediately.

SO, i'm guessing that's not the cause.

to be more specific about the hesitation, it's almost as if there's a specific dead spot, starting at maybe 1/8th throttle, where she just waits, stumbles, and tries to die. if you hold it there, she'll continue to gasp and sputter, whereas if you let off the throttle she'll clear up pretty immediately. if you hammer down on the throttle, she'll complain, but seems to slowly coax back and rev. (and, except for that spot, she seems great...flies down the highway and whatnot...)

does that help?
any other thoughts would be greatly appreciated!

[david s poole]

sounds like you will either need to adjust float level or clean dirt out of the jets BUT seeing as that is the infamous four barrel boat anchor where the aluminum parts will warp and suck air around the gaskets [always at an inconv time].company in cal developed holley carb for easy bolt on .jam engineering think they have web site.

[blankenship]

well, i've found some diagrams that might be helpful to resolving the problem, and may be useful to other euro gasser owners:
check out this post!

[blankenship]

my 'givens' are:
1. i've got (2) ports that pull vacuum from the carb/throttle body:
one pulls vacuum all the time, and varies with RPM's.
one doesn't pull vacuum at idle, but begins pulling vacuum upon acceleration.
2. i have NO retard port on my distributor or and no vacuum ports on my fuel pump.
3. i have a 'thermovalve' mounted in the block whose ports are capped.

from what this thread had told me, and the parts diagrams i posted above this reply, my best guess on vacuum routing is:

1. i connect idle governor to the carb port that pulls constant vacuum.
2. i connect the accelerator-actuated vacuum port on carb to the vacuum advance on the distributor.
3. i connect the top vac port on the fuel return valve to the accelerator pump suction port.
4. i connect the two bottom ports on the fuel return valve to each of the little ports on the bottom of the air cleaner housing.
5. i imagine i can just leave the capped 'thermovalve' alone. i'd guess it's supposed to get routed in between the carb and the distributor vac advance, to open up at 58º and start the advance (?), but it's okay to leave as is.

anybody with a better conceptual understanding wanna check the diagrams, car, or memory and see if any of that makes any sense?