To check the timing you will need a timing light. Put the ECM in
dianostic mode then set the timing to 10Deg BTC Your compression would
indicate that cam timing is OK
Axel Griese wrote:
> Camshaft timing, that is.
>
>
> My '86 2.8 v6 with 80,000 miles runs rough as hell - no power, coughs,
> backfires, etc. No ECM code, all I get is a constant stream of "12"s
> indicating all is well.
>
> Ignition timing seems okay - sort of. At TDC of the crank, the
> distributor rotor DOES point to the wire going to #1 plug, and then 2-3-
> 4-5-6 are correct, but #1 isn't #1 as stamped on the inside of the dist
> cap.
>
> It's almost as if either the timing chain has jumped timing and the
> previous owner just moved the plug wires to compensate, or the previous
> owner just put the distributor in randomly and called where the rotor
> landed as #1. I can tell somebody's had the distributor out because
> they've permatexed the old O ring rather than replacing it.
>
> I suspected a jumped timing chain, but I get good compression - 140 to
> 150 on all 6, not bad for an engine with 80K. Am I correct in assuming
> that good compression rules out a jumped timing chain ?
>
> My next step would be to check the camshaft to crankshaft timing. But I
> don't want to pull off the harmonic balancer if I don't have to. Is
> there another way to check camshaft timing other than looking at the
> gear timing mark ? Or does good compression rule out the need to do this
> ?
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