New to the w116 and M117.. need a little help gauging value

[mabbonizio]

Checked the chain tensioner yesterday after the car had sat for a few days and presumed it would have bled down.  It was rock solid.  I ordered all new guides and will install them when I check the chain stretch on sat for peace of mind.

In the mean time I adjusted the mixture about as good as I can get it.  The starts a little rough when cold and needs about 3-4 mins of time to run before I can touch the throttle. Then it will take off nice and smooth and is pretty quick til just about 2 - 2.5k, when it basically hits a flat zone of not acceleration. 

I pulled the plugs and they are white so I'm thinking its running lean?

I'm thinking this might be due to vacuum leaks? I ordered new injector seals as well as air delivery hoses since the existing ones are cracked.  Hoping this solves the issue.

[ptashek]

One very often omitted item is the air filter box to throttle body seal. It gets hard with time, and deforms from the heat around it, allowing false air getting into the intake manifold.

[mabbonizio]

Thought I'd post an update with some photos after I gave it a good wash today. Adjusted the mixture a bit more and got it running a bit better. I am thinking there is enough slop in the gas pedal so that I can not achieve full throttle. If i press the pedal all the way past kick down the car will kick down but will upshift between 3-4k rpm.  If I shift it manually it will wind all the way out and is much quicker. Testing from a dead stop today I got to 50mph in about 13 seconds. I had my wife push the gas pedal all the way down while I examined the throttle linkage and found that there was still a good 1/2" of travel til the throttle was wide open.









After about 20 miles and multiple fuel mixture adjustments I pulled the plugs. Wondering if anyone can give me some guidance on if this plug looks normal?

[daantjie]

With the pedal to the floor the vertical linkage at the throttle butterfly must be down tight. The adjustment to achieve this is in the linkage at the firewall close to the brake booster.

[mabbonizio]

Whew.. after adjusting the throttle linkage I feel a major improvement in response and power. Car drives great. Only nagging issue I have left is the faint surging/lack of power when I'm light on the throttle cruising at 40-60 mph around 2k rpm.  Has me a bit stumped.

[UTn_boy]

You likely have vacuum leaks, especially at the round seals between the upper and lower intake manifold plenums.  Adjusting the mixture with leaks present will cause this problem you're describing. 

[mabbonizio]

I'll be installing new injectors, and seals tomorrow.. thinking these are leaking as the car runs on for a second or two after I shut the key off.

Question: Does my motor have adjustable valve lash? I have a nice ticking coming from the passenger side of the motor that gets louder with increased throttle.
I'm thinking its an exhaust leak but it curious if it could be valve related.

[daantjie]

I'll be installing new injectors, and seals tomorrow.. thinking these are leaking as the car runs on for a second or two after I shut the key off.

Question: Does my motor have adjustable valve lash? I have a nice ticking coming from the passenger side of the motor that gets louder with increased throttle.
I'm thinking its an exhaust leak but it curious if it could be valve related.

The preload is adusted by way of "thrust pieces". You need a "go no go" gauge to measure the tolerance.

[rumb]

The trans kickdown is controlled by a rod at right rear of engine going down to trans.  Adjust that to change shift rpms.

If you decide to adjust your valves, I can rent you my gauge and I also have .7 mm stainless shims that can be used instead of spending $20 per thrust piece.

[UTn_boy]

Also make sure that the nylon bushing at the transmission end of the throttle lever is in good nick.  Part number 110-277-05-50. 

Regarding the engine run on upon shut off, this could be one of a few problems or a combination of several.  Make sure that your ignition and camshaft timing are in check.  If your idle is above 700-800 RPM, then that'll cause run-on, as well. 

The injector seals may or may not make a difference, but are never a bad idea to replace all these years later.  The ones I'm making reference to are further underneath, and are always leaky if original. 

[mabbonizio]

Thought I would update this... I replaced all the injectors, seals and holders today. The old holders were very cracked, o-rings trashed, and seals eroded.

This made a HUGE difference in driving.  I suspect the car still has some minor vacuum leaks but the general hesitation while cruising has gone away about 90%.

I played with the transmission linkage and adjusted it a TINY but since I figured small increments would be better.  This made a very minor effect on the shift timing.  In general I do not think the transmission is shifting as it should. with maximum throttle (kick down) it shifts right before 4k rpm.

[rumb]

Move the trans linkage a lot more.

[ptashek]

Maybe this'll be of some help, or at least an audible aid of how the trans should shift. That's my 450 doing 0-70mph when pulling out of a petrol station, without kick-down.
https://www.youtube.com/watch?v=voSgTwfES_A

When I first bought it, the control pressure rod was disconnected, and while it was still shifting OK, it was way early in the RPM range. It takes some experimentation to set it up.
This is how it was setup before the restoration, and it's near identical afterwards (top-left corner in the pic, click for full-size version).