Yet Another High Idle 4.0 OHV

[MazdaGreg]

Hello to all!

I've recently purchased a 2000 Ranger with the 4.0 OHV engine. Very familiar with this engine, since it was the same as the 93 Navajo I used to have. However, there is one big difference.

The Upper Intake on this truck is Plastic.

I've been battling a somewhat High Idle on this truck, and I'm wondering just how much of it is normal.

The truck will idle around 1200 - 1500 when cold, and then calm down to just under 1000 (Neutral). When warm, it will calm down to about 800-900 or so when in Drive.(After 10 or 15 seconds)

When the AC is on, and the Compressor Cycles, It jumps, and seems to be agressive, wanting to pull you through the intersection. This is new to me, since this is my first Automatic 4.0 OHV.

Can anybody comment on what their OHV 4.0 does? What typical Idle speeds are at idle, Drive and Park?

I have already done the Intake gaskets, IAC and Intake Cleaning, etc... This isn't my first rodeo.

Final comment. I have looked extensively for a vaccum leak, and cannot find one. However, this intake seems to sound very hissy... moreso than i am used to. Is this just due to the plastic (vs the aluminum my 93 had) or do these things have hidden leaks at their seams...

Thanks to All. Love this Forum. Been here a while now. Not planning on going anywhere!

G

 

[briwayjones]

The idle doesn't sound off too much once it warms up for an automatic. I think automatics stay around 800 or so while in gear? You can run some seafoam through the engine, clean the IAC valve and MAF sensor. That should help. How many miles are on the plug and wires?

 

[MazdaGreg]

Plugs and wires are fairly new, i'd say less than a year.

So your saying yours runs around 800 or so when in gear? When the AC kicks in, does it surge significantly? I'm talking a 200-300 RPM Jump.

IAC Cleaned. MAF Cleaned. No Seafoam yet.

Anyone have an Automatic OHV that they can comment on it's behavior?

Thanks to everyone.

 

[briwayjones]

Mine is a manual and normal is about 750. There shouldn't be much of a surge at all when the AC kicks in.