The Stovebolt Site Forums The Shop Area Engine Shop replaced the vacuum advance but...

is this coincidence or what? i replaced the vacuum advance but in the process broke the fitting off on the carburetor intake and also the oil pressure gauge won't work now!
i assume having the vacuum line not connected to the distributor vacuum advance unit wouldn't affect the oil pressure gauge, but i'll know after i go to the hardware store and get some copper to fix it.
i removed the plastic line from the block sensor unit and blew into it and my wife says the oil pressure gauge don't move. i blew pretty hard so i guess it's the actual gauge, not the sensor.
i hate replacing gauges because i have to remove everything on the dashboard almost to get to this one as it's the gauge cluster closest to the drivers door!
oh well, pretty much par for me; fix one thing and break a couple others in the process.

what type of engine are you trying to tear up

a gmc 228 6 cylinder. the stupid oil pressure gauge was working perfect until today, sits right at 45 pounds when driving it.

Hey old_blue-

This is a coincidence. The vacuum advance and oil pressure guage don't have anything to do with each other.

As far as the gauge goes, there isn't much of any way you could get it to register by blowing in it. It takes quite a bit more than that. But, I would agree that it is probably the gauge unit. I'm assuming it's the original mechanical unit. If it is, there is no sensor, just a piece of capilary tubing that connects the gauge with the main oil galley. Nothing more than a leak can happen to that end of things.

I doubt if it,s the gauge itself. Seldom do they go bad. You can suck on that vacuum advance & move it but I dont think you can blow hard enough to move that gauge needle. If you had the dist. out to replace the vacuum unit you probably have not got it down far enough to engauge the oil pump. You may want to spin the oil pump with a long screwdriver bit in a drill before starting it.

wrenchbender, please explain more.
this seems that it might be the answer.
i didn't know the dist turned the oil pump.
i did raise the dist a little to make it seat because the book said to raise it 1/16 of an inch i believe it says. do i need to shove the dist in further? seems to make a vibratiion if i push it in further.
also, i put my finger over the hole in the block where the plastic tubing goes into for the oil pressure gauge and don't feel any pressure. if it takes that much pressure to move the gaugue, wouln't i feel some of that pressure?
please advise and thanks much
tony

whoaaaaaa wrenchbender is right.. the dist should bottom out on the oil pump.. i dont remember what the drive connection is... the newer ones are just a slot..like a screwdriver slot... some were hex...some were offcentered slot,,,only go one way... if ya got the timing right then sometimes ya hafta push down a little while its cranking to get it to pickup the oil pump..inothere words it will engage the cam gear...but not on the oil pump yet... and ya cant check a gauge by blowin on it... ive tried blowin on a fuel pump tester and ya cant even blow one PSI of pressure...

wrenchbender, i owe you a cold one next time you're in southern california. i think you kept me from blowing up my motor! it was indeed the dist not far enuf down. i did like fatweed said (thanks to you 2) and pushed down while cranking the engine and it slipped down just a notch. now i got oil pressure! i still might need to touch up the timing, but its at 5degrees before dead center like the book says but i forgot to take loose the new vacuum advance i just put on, so it's probably off.
worry about that later; it's 100 degrees.
thanks again to all on this great forum for your help.
tony

Good news,, that is what this site is all about..Fred