is the idle a little eratic at times ? if so i suspect its the crankcase breather valve diaphram has failed.

Easy to diagnose, with the engine ticking over remove the oil filler cap & place a piece of paper over the hole. If it blows away the breather is fine, if the paper gets sucked to the hole then the diaphram has failed.

WARNING, hot oil will splash out the hole & beware of any rotating parts ! ie fan etc

These are also prone to air leaks around the manifold & vacum pipes & defective AFM's ( Air Flow Meters ) they just weaken right off ! making them very jerky on light throttle.

Also take a close look at the convoluted air inlet hose from airflow meter to inlet manifold.They are prone to split in the folds.hth