7 replies to this topic

[theunderlord]

Ok, I have a 1994 850 Turbo that doesn't seem to have much power these days....Looking at the boost gauge, it is pretty much at 12 o'clock all the time and barely moves if any at any speed. 

Where do I start?  I saw a thread somewhere about the wastegate rod to see if it has broken free, but it is solidly mounted.  Other than that, I don't know where to go. 

Any help would be appreciated!

Check all boost/vac lines. These cars are highly prone to boost leaks, and if they've never been changed on your almost 11 year old car... that's a really good place to begin lookin. The OE gauge in the car isn't really worth shiz.

[ziddey]

hmm that sounds like my car. open up your hood. you'll see a little plastic cover with a screw on it (throttle body cover). it's a torx screw but you shoulkd be able to take it off with a flathead

after it's off, you'll see a vacuum tree (you'll know when you see it) and there's a bunch of rubber elbows connecting tubes to it. most likely, one of the elbows will be killed on the inside, so the pressure is leaking out.

this was the case for me, because even if you don't boost, it should go into the negative pressure (vacuum), but my gauge would stick at 12o'clock and move slightly to the right under boost.

now after i spend the 50c or something for the elbow, it swings left and right

[b52murph]

Check the lines running under the battery as well. How's the cruise working? The previous owner of my `96 855 Turbo had a battery that leaked acid over the side and ate through the vac lines for both the turbo gauge and the cruise. After $5.25 at AutoZone and about a half hour of tinkering, both were working perfectly.

[ziddey]

Check the lines running under the battery as well.  How's the cruise working?  The previous owner of my `96 855 Turbo had a battery that leaked acid over the side and ate through the vac lines for both the turbo gauge and the cruise.  After $5.25 at AutoZone and about a half hour of tinkering, both were working perfectly.

oo this is interesting

because when i got my 94 855t, the cruise didnt work (still doesnt) and the boost gauge was shot

after that elbow, the boost gauge is good but cruise is still a dud

is there supposed to be a light for cruise on the dash anywhere? because i don't see anything when i turn it on. the last owner said the module is dead, but it woulkd be a lot cheaper if it were vacuum related

[b52murph]

Ziddy

No light on the dash; I found out what mine was the easy way. When I took the battery box out, the lines were both sitting there with holes it them. I took the hose off the vac pump (mounted on the battery box) and blew into it....no resistance. The simple splice in the vac lines was all that was required; 5/16ths vacuum hose does the trick.