Jeff928S4

Does the Idle Stabilizer only keep the idle level at idle?? (man, that sounds stupid...)

Here is the problem.

Driving in say, 5th gear - RPM's at around 4000. Put in the clutch and the RPM's drop to like 2000 and when I give it gas, it hesitates.

Does the I.S. keep RPM's from dropping - does the I.S. maintain the RPM's in the higher RPM range?

If not, anyone know what could be causing this hesitation/drop in RPM's? Air Flow metre? TPS?

This problem has been annoying me for a while, I know the car would work so much better if this was fixed.

944S Boyeee

Skip

When you roll to a stop with the clutch in does the idle stick or waver above 900 RPM - maybe around 12-1500?

The ISV only operates when the throttle is closed - it allows air [clean, metered] to bypass the throttle and enter the manifold to maintain a steady idle. A stuck-open ISV can cause idle problems.

The ISV relies on information from the TPS microswitch for closed throttle (via DME).

The hesitation could be a combination of things, but may be directly related to the cylinders being flooded by or starved of gas.

Jeff928S4

That's what it feels like - like there is an empty gas tank for about 3 seconds, then it kicks in. I think it's getting too much gas. What could cause this? Would a bad DME or DME relay cause this?

Pump? Or do gasoline pumps just "go", as opposed to an intermittent cuting out.

TPS? - but the throttle is usually "off" before I try to give it gas. I coast a lot on the highway in high gears and when I do give 'er gas, it takes a few seconds for it to kick in.

O2 sensor? This could cause the car to give too much gas or too little, no?

I dunno??

944S Boyeee

Tom Carson

you could check a few of these parts with a cheap multimeter & Haynes or FR Wilks website etc