Less Power??

[Ara T.]

I took my car in for an oil change (at Mission Plaza for anyone that lives in Santa Rosa) and afterwards it seems as if I have a lot less power. It seems as if the throttle won't open up as much! As in I have to mash the pedal way more than i ever did, at least after ALDA adjustments. They seemed like a decent bunch of guys, i watched em do the work but I suppose they coulda have kicked a couple vacuum hoses loose or something. I'm kinda angry cause I had my 300Dturbo running like a champ after ALDA adjustments and such.

Now, before I took it in there were 3 or 4 vacuum lines disconnected, i never figured em out. I found that vacuum diagram for my 1985 CA version but never figured out what all those fancy words like switchover valve, vacuum damper, vacuum transducer, control unit, etc were referring to But my car still ran ok so I never really bothered with them too much.

Anyways, today I found a loose vacuum line running from the turbocharger (its coupled with the EGR line) that doesn't lead anywhere. After a little bit of research i find this to be the air recirculator or something to that effect, could this disconnection be related to my power loss?

Now, before i researched this, I tried following the vacuum diagram and plugged it into...something... (what i thought was a switchover valve) and now my engine won't turn off, unless I pop the hood and push the stop lever (takes a good push, too). I disconnected this line but the engine will still run. Any ideas? D:

-Ara

[Fisherman]

Lack of power I would check the line from the back of the manifold to the overboost sensor, then check the overboost sensor to see if it got diconnected somehow. Then perhaps check the overboost switch on the top of the intake manifold to see if it shows an open circuit to the manifold. This means it is probably plugged up or has gone bad.

As for the shutoff it is most likely a massive vacuum leak. Bsed on all the disconnected hoses make sure that they are plugged and check to see if they accidentally broke an old one or knocked one loose.

I don't think the two things are necessarily related but they could be. I have seen the 85 turbo with the fitting on the front but I have no idea how this affects the car, sorry... Mine are all too old.

[Brian Carlton]

Originally Posted by Ara T.

Anyways, today I found a loose vacuum line running from the turbocharger (its coupled with the EGR line) that doesn't lead anywhere. After a little bit of research i find this to be the air recirculator or something to that effect, could this disconnection be related to my power loss?

Now, before i researched this, I tried following the vacuum diagram and plugged it into...something... (what i thought was a switchover valve) and now my engine won't turn off, unless I pop the hood and push the stop lever (takes a good push, too). I disconnected this line but the engine will still run. Any ideas? D:

-Ara

The loss of power is "probably" not related to the vacuum issues, but, I also don't know the '85 CA very well and from what I do know, it is unlike every other 300D out there, including the '85 Federal version.

You are correct regarding the vacuum hose to the air recirculation valve. This hose can "probably" be disconnected and plugged. The ARV is there for emission controls, primarily. But, you cannot leave the hose open because you will have a massive vacuum leak and the engine might not shut off because of this leak. Either connect the hose properly, or, plug it.

If the engine still will not shut off, search around under the hood for any vacuum line that is not connected. Put your finger over the line and feel for "vacuum" (I presume that you do not have a proper gauge). If you find any with vacuum pulling on your thumb, they must be plugged or connected to a device. Once all the vacuum leaks are fixed, the engine will shutoff like it should.

Regarding the power loss, please follow Fisherman's advice, above. If you are unsure of the terms that he has used, please post again.

A mityvac would be an indispensable tool for you with this vehicle (especially with this vehicle: "CA '85 300D"

[Ara T.]

So this overboost sensor, is it near the banjo bolt? I think i have read about it before, is it directly related to the banjo bolt? What's it look like?

[Brian Carlton]

Originally Posted by Ara T.

So this overboost sensor, is it near the banjo bolt? I think i have read about it before, is it directly related to the banjo bolt? What's it look like?

Follow the line from the banjo bolt across the back of the engine and it will terminate at the overboost protection valve, mounted to the firewall just in front of the driver. Make sure this line is clear. The valve should also be clear. You should get the same pressure readings both before and after the valve.