Had 1991 T3 "Crush" serviced last week before our family Easter trip. About 100-150km later he developed a very slight misfire, more of a hesitation at first. Over the next 500kms (over 3 days) it's become worse, the change from 1st to 2nd, and 2nd to 3rd will often cause you to bog down, lose power, i've snatched the next gear up and he's carried on valiantly. He sat on 100-110kph in 5th without any problem, and even accelerating in 4th was OK. Tick over/idling is smooth and revving in neutral is OK too. Today we replaced the fuel pump and filter, changed spark plugs, checked the leads, rotor arm and dizzy cap. Checked the timing. Even swapped MAF with another vehicle to try and isolate the problem. No joy. The minor service last week incl. new belts. new air filter, new oil filter and engine and gearbox oils. Anything else to check? Thanks in advance.