Jsonova99

So I had posted on this previously but I was able to make a few measurements (described below). Car need valve stem seals, I haven't pulled the covers but it exhibits typical symptom like blue smoke when starting shortly after running, when hitting the throttle after sitting in idle. Still smell oil in the exhaust, but only get smoke in those instances. So I'm pretty sure it's the valve stem seals (128k on the clock). Previous owner put a custom true dual exhaust on the car, only get the oil smell and smoke on driver side.

Vacuum:
COLD: vacuum reads very low, the idle is rough and needs to be feathered the first few seconds to run and it also hunts up and down for idle. Thinking a vacuum leak.
HOT: Once warmed up it runs at about 17mm right on the cusp of the green zone (using harbor freight vacuum gauge). It moves around some slowly but random. When you rev it, it drops to zero recovers and settles. If you slightly increase throttle it rises slightly and is rock solid. I think some of the fluctuation at idle is that the idle is not completely stable. Trying to post some videos.

Compression:
Only able to measure 6/8 cylinders. Could not get the hose to thread in on two of the cylinders (2 & 8). Will have to try again, but below is what I got for the other 6, all within 10% of each other. Measured with engine warm.

1 175
3 185
5 175
7 172
2 NA
4 175
6 170
8 NA

Will update compression numbers when I can get the last two cylinders. I'm trying to determine whether I just have an intake manifold leak, bad injector, possible misfire, or bad valve guide(s). Don't think the stem seal would affect either of these tests.

Jsonova99

Here it is cold while warming up with the erratic idle and hunting from 400 to 1200. I read to do the test warm, but I was curious to see what vacuum looked like when it's at its worst.

aklim

I'd fix the valve stem seals first. Check compression of the last 2 if you can. After that, we can talk about removing the TB, top plate, IAC, IAC housing and clean everything. Also if you have Multec injectors, might as well toss them and get reman from FIC.

Jsonova99

aklim

Original what? Bosch or something else, no problem. Multecs big problem unless you tow a supply of pure gasoline around. It does not play well with ethanol so you have to go to stations that do not have ethanol and that limits you to certain stations and overpriced products. Either way I'd get a reman set since they are probably having some varnish built up from years of sitting.

Jsonova99

xrav22

If it is hunting for idle spray water on each cyl at the exhaust manifold and see if one cylinder is not working. Found number 7 fuel inj plug corroded , cleaned and no more hunting idle.
Good Luck

Jsonova99

aklim

Or crazy idea. Infrared thermometers. They sell them HERE and instead of changing something like a CTS or Ambient air temp sensor, you can scan the ECM to see if it agrees with the IR thermometer.