I hooked a vacuum gauge up to my Camaro, I am getting 15" of vacuum with a slight needle movement between 15-16". Where is all my vacuum going...uh..

 

2.8s make less vacuum then typical sbc, looks like your reading is close to stock.

 

yeah thats pretty much right on, iirc my old 2.8 made 18inches of vacum when it was stock

 

I thought stock was between 17-21" vacuum? Isn't 15" too low, and a needle movement between 15-16" a bad thing?

I was curious so I performed a compression test in PSI,
1-160
2-170
3-165
4-160
5-170
6-170

This is a dry test. Didn't do a wet test (Didn't have any oil on hand)

 

the needle moves from the pulses in the intake thats normal, with normal wear and tear over the last 20 years 15/16" is quite an acceptable number

a much better test would be to do a compresison check and a leakdown test on all 6 cyls and see what u come up with

 

Really? Car only has 80K on it. Huh...I believe I am getting poor gas mileage around 11-12 or so in city. I put 5.19 gallons in, and with the fuel needle were it was previously (before 5.19 gallons added) on flat ground engine running, I drove about 65 miles. Which is low, compared to the stock mileage at around 17 according to others.

 

recent tune up?
is the cat on the car starting to get cloged?
have u ran seafoam threw the engine ever?

seafoam is about 9 bucks a can and u get 2 uses out of it, i personally love seafoam as ive torn down an engine after using the seafoam and seeing how well it cleaned everything up inside

so if u have recently done a tuneup and all that and everything is in good shape i would do a half can of seafoam in the engine and the other half in the gastank to clean out the fuel lines and injectors and i bet ur milage will go up a good bit

 

More then a tune-up...New timing chain, new cap, rotor, distributor, new spark plug wires, new plugs, new carbon filter, new MAF, new air filters, new oil/filter, new EGR, new ignition coil.

I just ran seafoam through it last week, both gas tank and brake booster hose.

I don't think the cat is clogged, it was recently changed within 3 years or so. I would have to check (Real PITA without an oxy torch).

One thing I do notice is an occasional code 32 but I believe it is being caused by gasket material getting into the vacuum lines from my stupid old EGR. I did run compressed air in the vacuum lines, hoping that will fix it.

 

try changing ur driving habbits, most ppl forget that driving habbits have the biggest impact on fuel milage

 

Make sure you have a good 195* t stat, a cooler running efi engine will use more fuel then a hot running one.

 

I have a 160° thermo in mine and it still gets way over 220 almost pegged. While running dual fans, new water pump, new radiator and timing set at 10°.
I wanna get a fuel pressure gauge, and vacuum gauge. I already have an air/fuel ratio gauge and it where it's supposed to be.
I can Only imagine how hot it would get with a 190° thermo.

And yes there is antifreeze in the radiator and half way up in the resevior.

 

I guess this is off topic but how is your car putting out 220+f coolent temps with a 160* t-stat and dual fans? Do the fans come on??
My car for example has a 180* t-stat and if I leave the single fan on it will never see 190 degrees even on a 85 degree day and beating on it in town or outta town.

Im thinking your fans are coming on at the stock tempeture?? IIRC 225 or so was in the stock bin file?? You might wana change that or piggy back the relay on the fire wall so that you can override the relay and turn it on when you want to, if you want it to run cooler.

 

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If your vacuum gauge is reading too low, and your engine compression is good in all cylinders, either your idle RPM is set too high, you have a vacuum leak after where the vacuum gauge is connected, or your air/fuel mixture is bad (needle movement). Being that your saying that your getting bad fuel mileage, it very well might be the latter. Check your fast idle screw and IAC and make sure they are set to where they need to be, check for small vacuum leaks after the vacuum gauge port, and check your BLM's...