1. just finished plenum gasket and timing cover gasket replacements
2. engine running rough
-before replacement, engine ran smooth, idled at 500 rpm
-after replacement, engine idles at around 1000 rpm. runs rough,
when accelerating there is a vibration feel
3. I was very careful to re-connect all connections. but I am going to
recheck them
4. I have driven about 27 miles since repair.


How long does it usually take for the computer to re-set air-fuel mixture?
What advice or suggestions do you have to solve the problem?


thanks to forum member and readers for helping

 

You've got a problem. Check your spark plug wires and other connections.

 

Did you also replace the timing chain since you replaced the timing cover gasket? Did you remove the distributor?

Sounds like you might have a vacuum leak.

 

Someone else just had a pinched (pinched off) vacuum line after doing theirs...

 

tks for the replys
I did not tamper with the spark plug wires or the distributor.
I did not replace the timing chain (it looked pretty good plus I only
expect to drive the truck about 50000 more miles)
Another part I replaced was the oil pressure switch/sender (broke
it when loosening the egr tube)
Tomorrow I plan to conduct the simple vacuum test (plug pvc/breather
ports/hoses and feel for suction or pressure at the oil cap)

 

1. after a closer examination of the spark plug wires, I discovered one of the boots was disconnected from the distributor (had to feel to find it, not visible to see with manifold installed).
2. truck now runs smooth.
3. so far the plenum gasket replacement has worked. have traveled 300+ miles since repair and no oil usage (truck was burning qt every 400 miles before repair).

 

Thanks for update!