86 2.5 ignition trouble

my 86 pioneer with the 2.5 litre keeps coffing and gagging under load.all the symptoms point to a timing issue,but the timing is non-adjustable.i replaced the plugs and wires about 7000 kms.ago.i thought maybe a vacuum leak but there is nothing obvious.any tips?? am i missing something?? :gonnablow

fuel filter?

changed it in january

I had the same problem(s) on my 85 2.5L.
Going over the vacuum system with a fine tooth comb replacing worn out and brittle lines and sealing the soft boots on the hard plastic lines with silicone cured it....
Good Luck the vacuum system on these is a nightmare!!
Are you in the neighborhood of Woodstock in Portland, Oregon?

no man,woodstock ontario,canada EH!,i kinda figured that might me the problem but i just dont want to tackle the load of spaghetti(hoses)on top of that motor:bs: