5 cyl., almost NAC

[Tihol Tiholov]

Gents,
apologies for mostly NAC but seems not much is happening, so I'm
trying. Patient is a '92 Eurovan, 5 sp., 220K kms. Did my first trip
with it, 1000+ kms and have 2 issues.
1. Cooling fans seem to come on, when temp. gauge shows a bit above 90
deg. Days have been warm (above 30 deg. C) but still nor sure, if this
is normal behavior. The coolant warning light blinks intermittently,
which as per owner's manual, means overheating or low coolant level -
neither is the case. Had a trouble code re: temp sensor, swapped a new
1 in, no change.
2. More important issue - power delivery is uneven, jerking back and
forth. Can feel in my back at times a push and release of power, when
pressing the throttle. Most pronounced is under acceleration and going
uphill. I had TPS trouble code - sprayed liquid wrench in it, when
partially disassembled. 4 clips are holding it together and are very
brittle, so didn't fully take it apart. Deleted codes and have not
come back. Will check again tomorrow. This may be related - swapped in
new CV boots on the driver's side axle, pass. side axle is all new.
Not sure, if a loose CV joint would act like this, never felt this
before.
Thought of spark plugs and can change them but fuel consumption is
good - 11 L/100 kms or less.
What would cause jerking under heavy load?
Any ideas appreciated.
Thanks,
Tihol