A day of testing

[ll77]

I have a 76 280z that runs rough, lacks power, and is quite gas-inefficient. I checked my air temp sensor and water temp sensor w/ a multimeter, and they read acceptably. I hooked up a vacuum gauge with a T at the FPR vac line, and these were the results:

 

~10.5 in Hg @ 800 rpm (not jumpy, but twitchy)

(I don't have a tachometer yet, sorry)

drops to ~4.5 in as throttle is applied

raises back to ~10 in to WOT

up to ~20 in @ throttle release

 

Fuel pressure (gauge is not very accurate)

39 psi (idle)- 42/43 psi (throttle applied)

 

I tried messing with the AFM (PO put wrong one on the car)- gave it more fuel while also decreasing idle back to 800 rpm (my dad was screaming the tach reading to me over the exhaust hahaha) and my vacuum started drifting steadily between 15-17 inches, which would be more acceptable.

 

I don't have any big irregularities except for the fact that the vacuum is SO LOW, and I understand that is causing my very high fuel pressure.

 

I checked my valve timing, I cranked the crank pulley till the timing mark was at 0 deg BTDC, so TDC.

 

Weird side note: my intake/exhaust cam lobes were making 11:15, if the intake were the hour hand and exhaust was the minute hand (relative to timing chain). Also the dizzy was pointing underneath the upper radiator hose, looked as if it were already touching the #1 plug wire contact. That don't seem right.

 

So anyways, I looked to the marks on the cam sprocket, and the triangle was waaaay to the EDIT**right of the mark. So I'm too advanced, I wonder how that happened.

 

Then I decided to look at my PCV valve, so I popped off the hose under the BCDD going to the intake manifold, nothing there! Just a bunch of carbon. Whaatt? I need a PCV valve.

 

SOO, I've gathered I need to adjust my valve timing, and the right model AFM would help too, yeah? What do you guys gather from this? Thanks a bunch for any input!

Edited August 17, 2011 by ll77

[AtlantaZ]

Yep, you definitely need a PCV!