I have a 87 Corolla FWD 8V carbureated. I was replacing spark plugs and tried to index them. They were maybe fitted too loose. The engine was running rough at idle and moving, made this puff , puff, sound like a model T. Car is shaking in high gears like 4th and 5th because the engine in general is running rough and low on power. . Even I re- tightened the plugs, same problems persist. What are the problems? Loss of compression thru spark plug holes, timing or firing order out of sync, the shaking jarred something loose? And how to fix the problems. Please kindly reply for answers. Thank you for the awesomeness,, and generousity.
Thank you very much.
Thank You for writing into AskPatty!! These models have a known problem with the Auxillery Air Pump (AAP) The diaphram can age and dry rot causing it to split and have an internal vaccum leak. This may be a starting point, and you may be able to locate one from a salvage yard to insure this is the problem before digging deeper.