my disco will not idle, i suspect the idle valve or signal

i have replaced the plugs/rotor/cap/wires, ign mod, msd coil, o2 sensors, maf and upper head set

the timing is off a hair, but i dont have my tools with me

i guess my next trick will be get the tiing right and then check the base idle

70k 95 disco1 3.9

thanks

 

If it just flat out will not idle but will run if you hold your foot on the gas then it is your idle control valve, also known as the stepper motor.
www.atlanticbritish.com

http://www.roverparts.com/Parts/ERR5199.cfm
Take your out and clean it with carb cleaner, also clean the whole are that it goes in.

 

Let's not be so quick Spike.

If it never idled after the head job, I'd be looking for a vacuum leak before I looked to the IAC valve. Especially if there were no IAC related idle problems before the head job.

Most common area for a leak is the upper plenum half.

 

i did swapp the idle valve, i forgot to list that

it idles too low, or not at all, i idled it up w/the cable so it would not stall once for a day, but it idles up sometimes, so i guess the idle valve works here or there at least, and it is new

 

I would have to agree with PT and say that it is a vacum leak then.

 

are you thinking that the vac leak is confusing the system? it never idles high except when i tightened up the cable

i was thinking timing or tps maybe, i guess i can go out w/a can of something and see

 

First off, I don't disagree with folks just to disagree with the-in spite of how it might seem at times!

I love these stupid trucks and like to think I have a good handle on what makes them tick.

The issue is that if you have a vacuum leak, you're not getting enough fuel into the combustion chambers at idle. When you open the throttle, the ECU pumps enough fuel to overcome the air leak and the engine smooths out.

IAC valves are probably second only to oxygen sensors for replacement of good parts!

I once did a head job on a truck where I had the exact same problem. I finally pulled the upper plenum off, cleaned it up, applied a nice even coat of high-tack and away we went!

 

what is high tack? the upper is easy enough to get off, ill try anything to get this thing right

 

PT, nobodys saying that you are being difficult, weall are just trying to figure this thing out.
I too love the simplicity of these trucks.

 

Permatex gasket sealant