If anyone knows where to find a vaccum diagram, can you post a link, or email it to me? tlp48@hotmail.com, just be sure to put this message board in the subject so we dont delete it...We are having problems with the speedometer, and A/C, the car will run great and normal, then all of a sudden the speedometer will drop to 0, the A/C won't work and the car doesn't want to run right, cuts out, sometimes stalls

If you can help with this, we appreciate it!

There should be an emmisions sticker on the car that will give you an idea of where the Vac. lines go. My 89 Sunbird had one on the Hood.... Showed Vac. lines comming off the throttle body, going to various stuff.

If you don't have that, I'll see if I still have my Haynes manuel for it... Try to post some pics.

Can't help with the speedo... It should be electrically controlled.... Maybe having electrical problems with the ECM... that would explain alot with the car's behaviour. Have you checked the ECM for any trouble codes??

when we first got this car a month ago we hooked up the code reader and it came up with #12 system ok, but it still acts up, so we change the ox sensor and plugs and maf. unhooked batt so i would reprogram itself again and now we can't get no codes out of it, i will check under the hood for the vacc diagram, we can drive maybe 5 miles and it cuts out stop running like it's out of gas sit a bit then it starts again,when it runs crappy there is black smoke coming out of the exhaust, but when the speedometer is working it runs great no smoke alot of power, wondering if it aint the main brain box, thank you for your help

on this 1991 Buick Skylark 3300 V6, where(if equiped) would I find the MAP sensor? My manual doesn't clearly point it out...Any help is appreciated! Thanks!

on this 1991 Buick Skylark 3300 V6, where(if equiped) would I find the MAP sensor? My manual doesn't clearly point it out...Any help is appreciated! Thanks!

Since the 3.3L is a early version of the 3.8L, There probably isn't a MAP sensor... There should be a MAF sensor insead.... Located right infront of the throttle body, or in my Haynes manuel... Right above the upper rad. hose on the block.


But if I'm wrong, check for a 3in long, 1in wide box with 1 vac hose and a 3 wire harness somewhere on the pass shock tower, firewall, or rear valve cover.

But I'm pretty sure it doesn't have one.

Also... If you're scanning your puter and its not flashing the code 12... there's definatley something wrong with that. Are you using a scanning tool, or shorting out the two pins in the Diag. terminal??