vacuum troubles

I have an 83 300SD that has a vacuum problem. It shifts harshly and jerks alot when I mash the pedal. The problem seems to do better when the engine is warmed up, so I was wondering if anyone knew what part could be the problem without having to do all the vacuum testing.

Reply to
anahataray via CarKB.com
Loading thread data ...

I had a similar problem with my car recently after an engine swap. A mechanic made an error in the vacuum connections. After an adjustment of the vacuum control valve at the rear end and on top of the injection pump (the white plastic device with a lever) it was a 30 second fix,

In your case there really is no substitute for a check of the vacuum system. The procedure is not difficult, but you need to buy (or borrow) a simple vacuum tester (for about $15). Courtesy of Richard Sexton here is just the link that gives you the test procedure:

formatting link
You will find the problem fairly quickly.

Reply to
jch

There's a bunchof parts that can leak. Some you can test without a tester if you're brave enough to take pieves of tubing (and connectors) off one at a time, suck on the with your finger over the end and see what leaks (and tastes bad).

Have a look here:

formatting link

Reply to
Richard Sexton

Too bad they don't seem to cover the Auto tranny in the 124 gas model. Mine has zero slip, and practically give you whiplash sometimes. IT will even bark the tires every now and then when shifting from first to second on hard acceleration.

Reply to
Thom

The shifts' harshness IS vacuum controlled. The MORE vacuum to the transmission's shift modulator the SOFTER the shift will be, Conversely, at wide open throttle NO vacuum is supplied, by design, so WOT shifts are quick and crisp.

You need to check that the vacuum line to the modulator is intact. If so, then there's a leak somewhere, probably in a door lock.

There's no shortcut, that's what needs to be investigated.

Reply to
T.G. Lambach

Cool, I'll attack it. I have to find out what happened to my backup lights anyway. When I replaced the Shift Lever bushings, I think I popped the connection off.

My door locks seem to work f> The shifts' harshness IS vacuum controlled. The MORE vacuum to the

Reply to
Thom

Find Dave Meimann and write to him. When you get an answer lemme nkow and I'll add it to that section.

Reply to
Richard Sexton

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.