MITCHELL 1 ARTICLE - D - ADJUSTMENTS 1991 ENGINE PERFORMANCE Ford/Mercury - On-Vehicle Adjustments Page 1 of 3 Back To Article D - ADJUSTMENTS 1991 ENGINE PERFORMANCE Ford/Mercury - On-Vehicle Adjustments ADJUSTMENTS ENGINE MECHANICAL Before beginning any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay. VALVE CLEARANCE NOTE: All models are equipped with hydraulic lash adjusters. No adjustments are required. IGNITION TIMING CAPRI 1. Place automatic transmission in Park or manual transmission in Neutral. Disconnect and plug hoses attached to vacuum diaphragm assembly on distributor. Connect tachometer and timing light. Turn off all electrical loads. 2. Start engine, and warm it to operating temperature. Ensure idle speed is set to specification, adjusting if necessary. See IDLE SPEED & MIXTURE . Determine initial timing. See IGNITION TIMING table. If base timing is not correct, loosen distributor mounting bolts and rotate distributor until marks align. Tighten bolts to 14-18 ft. lbs. (19-25 N.m). 3. Increase engine RPM while observing timing light. Verify ignition timing advances. For Turbo models, go to step 5). For non-Turbo models, continue with step 4). 4. On non-Turbo models, apply 16 in. Hg vacuum to chamber "A". Verify timing advances by 26-30 degrees. Remove vacuum source from chamber "A". Apply 8 in. Hg vacuum to chamber "B" while observing timing. Verify timing advances by 3-7 degrees. Stop engine, and remove test equipment. 5. On Turbo models, apply 20 in. Hg vacuum to advance diaphragm. Verify timing advances by 13-17 degrees. Disconnect vacuum source. Apply 8 psi (.6 kg/cm2 ) pressure to advance diaphragm. Verify timing retards by 3-7 degrees. Stop engine, and remove test equipment. FESTIVA 1. Place manual transmission in Neutral or automatic transmission in Park. Turn all accessories off. Locate one-wire STI (Black) connector near master cylinder. Using a jumper wire, connect STI terminal to ground. See Fig. 1 . Connect timing light and tachometer. Fig. 1: Locating Self-Test Input (STI) Connector Courtesy of FORD MOTOR CO. 2. Start engine, and warm to operating temperature. Ensure idle speed is set to specification, adjusting if necessary. See IDLE SPEED & MIXTURE . 3. Check initial timing. White timing mark should align with white mark on crankshaft pulley. If marks do not align, loosen distributor mounting bolts and rotate distributor until marks align. Tighten bolts to 14-18 ft. lbs. (19-25 N.m). 4. Remove jumper wire. Increase engine RPM, and verify ignition timing advances beyond initial setting. Stop engine, and remove test equipment. IGNITION TIMING http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D... 3/10/2009.