Vacuum looks pretty good on this 88...

[jimdigs]

I am using the right hose to check this with right? Have the red arrow showing which one I used. I also added a pic of the cross bar right under the radiator (its fuzzy) but just wanted to show how intact it is, nice and solid. This car really needs to be saved from this Michigan weather.

[WmWatt]

I don't know but I use the top hose and that works. Also don't know if the top hose is the best to one. I do know I have to pull the hose off and stick it on the guage quickly or the engine dies.

[jimdigs]

I don't know but I use the top hose and that works. Also don't know if the top hose is the best to one. I do know I have to pull the hose off and stick it on the guage quickly or the engine dies.

When I tried the top hose the gage read in the red zone around 15. When I put it on the bottom hose I get the reading you see. Also, I could pull either hose off and it would not die. It slowed down a little. I hope I was on the right hose?? Otherwise I have horrible vacuum. What do you think Wm?

[WmWatt]

Sorry, I'm no engine expert. Your difference probably relates to where the ports at the other ends of the hoses enter the carburettor or manifold. Have you cleaned the carburettor with carb cleaner recently? I do mine anually as part of a minor tuneup.

[jimdigs]

Sorry, I'm no engine expert. Your difference probably relates to where the ports at the other ends of the hoses enter the carburettor or manifold. Have you cleaned the carburettor with carb cleaner recently? I do mine anually as part of a minor tuneup.

I'll do that this weekend. Supposed to get up into the 50s this weekend.

[tooldude]

jimdigs, the vacuum line on the top port of the distr. vacuum advance should trace back to a port on the intake manifold below the carb base (driver's side). That's the hose to test with because it's manifold vacuum. The side port of the dist. vacuum advance should trace back to ported vacuum at the rear of the carb; however, it first routes through a metal vacuum line beneath the intake manifold. Make sure the vac hoses are not reversed.

[jimdigs]

jimdigs, the vacuum line on the top port of the distr. vacuum advance should trace back to a port on the intake manifold below the carb base (driver's side). That's the hose to test with because it's manifold vacuum. The side port of the dist. vacuum advance should trace back to ported vacuum at the rear of the carb; however, it first routes through a metal vacuum line beneath the intake manifold. Make sure the vac hoses are not reversed.

Well, I hope they are reversed otherwise my engine has terrible vacuum. I'll check it out. Thanks

[jimdigs]

So I checked my vacuum hoses and they seem to be connected where they should be. Here is a photo of the bottom hose and it is color coded red as is the metal tube it goes to. If I do have to use the top port of the vacuum advance to check my vacuum, then I have issues.

[WmWatt]

See what happens after cleaning the carburettor this weekend. You might want to try blowing into that top hose to see if it's blocked and that could remove the blockage as well, if any.

[jimdigs]

See what happens after cleaning the carburettor this weekend. You might want to try blowing into that top hose to see if it's blocked and that could remove the blockage as well, if any.

I will tomorrow. Thanks for the reply. Appreciate it.

[jimdigs]

Well, I sprayed the carburetor down real good. Put the gauge on the top post and now I got absolutely no reading at all. I put it on the bottom one and get the same good reading I have in my original post. I did a compression test and found low compression on my two center pistons. This may be my problem?

[WmWatt]

Compression test depends on how low. I've read that low compression on neighbouring cylinders can indicate head gasket leak between the two.
Just curious. Were you able to blow any air through that top tube?

[jimdigs]

Compression test depends on how low. I've read that low compression on neighbouring cylinders can indicate head gasket leak between the two.
Just curious. Were you able to blow any air through that top tube?

My readings from left to right were 140, 110, 110, 170. No I never did blow through that top tube.

[FestYboy]

Cyl 1, 2, & 3 are all low. You should see at least 150 on a good running but well worn engine. Mid 180s to 190s is a healthy engine, and several members here have see low 200s...