my appologies right to start with..but need US car fellow experience..PLEASE!
please help for diagnosis on my Corvette (my second toy besides Pantera 4907 GTS) ..well ok not a Ford but Chevette 327 Small Block Gen 1, turbo fire 350 HP (may be I do not know as a replaced engine)
Symptoms since today Oct 1:
a) MISS FIRE at left bank at acceleration with detonation in the exhaust
b) rough engine winding up
c) oil gets pretty quickly dark after refill..I check it every 150 mils, replaced it after buying the car after 300 mile, black soon
Analysis at an engine test per Sept 15:
1) did check the spark plugs say 200 mile ago.. nr 3 was NOT GOOD with a SHORT (some metal material at the tip) and a black kernel
2) all other spark plugs good grey...( I replaced all of them on Sept 15, 300 miles ago then)
3) compression all over 190 psi only nr 3 was 161 psi (thought/hoped the SHORT was the issue - guess a mistake?)
4) NOW: slightly smoke on the left side from exhaust at idle and much more at acceleration comp. to right bank side - i.e black smoke at acc..
5) negative pressure at intake level was only 10 psi on Sept 15 (if I winded up the ignitan advance the pressure goes up at idle, still not in the green space on the US instrument for V8s)
6) Oil pressure top constant 30 at idle and then up, no issue at hot oil /engine
Engine knowledge:
x) I assume the car when I bought it 1000 mile ago has been sitting some where for longer...NO DETails avail.
y) it is a replacement engine
What is your guess please? Stuck Exhaust lifter?
Danke
Matthias a fan of US V8 vintage engines