|
Good bets for your idle/stalling problems are:
o Dirty Throttle Body. Remove for proper cleaning -throat, plate, plate edge and all orifices. Also clean the flame trap & make sure all PCV hoses are clear and snug fitting. If problems persist after a thorough TB cleaning then a TB and Throttle Position Sensor Switch check and adjustment should be done. If there's any chance that someone has been monkeying with the throttle body adjustments in order to raise the idle then you'll need to perform a full throttle body adjustment starting with the throttle plate adjustment screw all the way up to the tranny kickdown cable.
o Dirty idle air control valve. Remove for proper cleaning of valve chamber. Be prepared to replace the IAC valve if it's worn -symptoms are an inconsistent or wavering idle rpm.
These are basic maintenance items and should be performed ideally every 2nd service interval (oil change). As I've said many times, your B234F 16-valve is a bit more prone to intake deposits compared to the other red block engines, especially in short haul driving where the engine doesn't get a chance to really warm up and in city driving where the engine is typically low revving. At the same time you should be cleaning/gapping/replacing the spark plugs more frequently with a B234F, again like every 2nd service interval. Your B234F will be happier and cleaner if you always use premium gas with a good cleaner additive and occasionally give it a good highway run. Chevron with Techron is mentioned here frequently, but just find a brand that works for you and stick with it.
For more information on this and other problems always be sure to check the 700/900 FAQ (upper right pull down box on this page). In particular, check out the section on Engine Tune and Performance and the section on using OBD Diagnostic Procedures with Test Mode 2 to check TPS functionality (note that the test for full/wide open throttle is not applicable to your LH 2.4 system) and Test Mode 3 to fully exercise the IAC valve (let it cycle through perhaps a dozen times).
For your stumbling and electrical problems, it's likely either your alternator isn't charging properly or your battery is gone (or both). A common problem is a worn brush/regulator pack inside the back of the alternator. Remove the regulator pack and check that the brushes extend at least 1/4" out from the holder (absolute minimum is .2"; more if the commutator is well worn). To check alternator output use a digital volt/ohm meter (DVOM) directly at the B+ (fat red wire) and D- (blue chassis ground cable) terminals on the back of the alternator. With a fully warmed engine and all electricals turned off, at 2000+ rpm you want to see in the neighborhood of 13.5-14.2 volts (depending on ambient temperature). This alternator output test isn't valid with a bad battery. If the battery is more than 4-5 years old (less if you live in a hot climate) then definitely put it on the suspect list. To check the battery output and capacity properly you need to have a load test done from full charge (normally at a shop). Where the cells are accessible, give it a full charge then use an hydrometer (they're cheap) to measure the specific gravity in each cell (top up any cells below the meniscus split-ring using distilled water) -you want to see a specific gravity close to 1.265 (definitely above 1.225; a totally dead battery is 1.12). Additionally, after giving it a full charge, re-connect the battery, turn the headlights on for about 1 minute then disconnect the battery, let it rest a few minutes and measure the voltage across the battery terminals -you want to see in the neighbourhood of 12.6-12.8 volts otherwise cells/plates may be gone (anything below 12 volts is as good as fatal). You may need the radio code after disconnecting the battery, but the stock radio in your car doesn't use one.
For more information on this check the 700/900 FAQ section on Engine Starting and Charging.
--
Dave -940's, prev 740/240/140/120 You'd think I'd have learned by now
|
