Toyota Corolla, Geo, Chevy Prizm Repair Manual 1993-2002

This 1993-2002 Toyota Corolla, Geo Prizm and Chevy Prizm DIY repair and service manual by Haynes, covers all models.
Book Excerpt: 1993-2002 Toyota Corolla, Geo, Chevy Prizm Repair Manual GENERAL ENGINE OVERHAUL PROCEDURES

VALVE COMPONENTS

17. Check each valve spring for wear (on the ends) and pits. Measure the free length and compare it this Chapter's Specifications (see illustration). Any springs that are shorter than specified have sagged and should not be re-used. The tension of all springs should be pressure checked with a special fixture before deciding that they're suitable for use in a rebuilt engine (take the springs to an automotive machine shop for this check).
18. Stand each spring on a flat surface and check it for squareness (see illustration). If any of the springs are distorted or sagged, replace all of them with new parts.
19. Check the spring retainers and keepers for obvious wear and cracks. Any questionable parts should be replaced with new ones, as extensive damage will occur if they fail during engine operation.
20. Any damaged or excessively worn parts must be replaced with new ones.
21. If the inspection process indicates that the valve components are in generally poor condition and worn beyond the limits specified, which is usually the case in an engine that's being overhauled, reassemble the valves in the cylinder head and refer to Section 11 for valve servicing recommendations.

EMISSIONS AND ENGINE CONTROL SYSTEMS

AIR CONDITIONING IDLE-UP VALVE CHECK (Refer to illustrations 5.15, 5.16 and 5.17)

14. Connect a tachometer according to the tool manufacturer's instructions (see Step 4). Start the engine and allow it to reach normal operating temperature and idle speed, then turn the air conditioning system ON. The engine idle speed should increase slightly.
1. If the engine speed increases as described, the air conditioning idle-up system is operating properly.
2. If the engine speed does not change or if it decreases, measure the air conditioning idle-up valve resistance.


15. Disconnect the air conditioning idle-up valve electrical connector (see illustration).
16. Measure the resistance across the two terminals on the valve (see illustration). It should be between 30 and 34 ohms. If the resistance is not as specified, replace the valve.
17. Apply battery voltage across the terminals and check that air flows from port E to port F (see illustration). Remove battery voltage and observe that air does not flow from port E through port F.

Subject: 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Toyota Corolla, Geo and Chevrolet Prizm service, maintenance, repair. ISBN-10: 1563924552 | ISBN-13: 9781563924552 | Haynes 92036