I have a 90 factory service manual to work on a 93. I know the 90 came with a 4.5 and the 93 came with a 4.9. Is the timing still set at 10*? I have a slight idle miss thats not throwing any codes. All new electrical components involed with a tune up where replaced except the coil pack. cleaned throttle plates front and back sides, cleaned the erg tubes, checked for vacumm leaks, none to be found. No lurching at cruising speed ,typical of a vacumm leak. thinking injectors clogged. getting occordingly to my FDC 9 miles to the gallon around town, which I think is wrong. Whats everbody eles getting? I am going to recheck the timing again tommorrow. Any other ideas?