Idle raises once the car is warm... 92 1.6TD

[mk2vr6]

So I just got the injection pump retimed by Dr. Diesel, and the car runs and fires up perfect now.

However, the car is idling a little weird now.  Basically, the alternator was pooched on my car and i couldnt tell how high it really was idling, but now I can.  

When I start up the car, it settles into a nice 800ish RPM idle...  about 1-2 minutes after I start it up, its almost as if a swtich goes off and the idle just raises right up to 1200-1400 RPMs!  Its high enough to hear the turbo really start whirring!!

I cant imagine this helps fuel mileage at all, not to mention it is annoying as hell to hear the car revving way up.

Is this as simple as a fuel screw adjustment?  Has anyone else had this problem, and could you tell me what might fix it?  Thanks guys.

[jtanguay]

does your car have a/c?

[mk2vr6]

Yes, it does.

[jtanguay]

i'm not exactly sure how it could be happening, but maybe the a/c idle boost is coming on for some reason? do you have the defrost on??  makes me wonder why it doesn't idle high from a cold start though...

not that the idle boost should raise it to 1400 rpm or so... but it does raise it a bit.

i dont think my pump has the a/c idle boost, but when i have a/c on it doesnt really affect idle.  

maybe something in the pump is buggered up?  all i can think of.

[mk2vr6]

Well, it is weird.  when i tried messing with the a/c when I first got it, it hardly affected the idle at all.  Once the idle goes high after 1-2 minutes, it doesnt come back down.  

I really have no idea what it might be....  This would normally seem like an ECU or wiring issue to me but ummm...  not in a diesel!

[ricosuave]

well, obviously your idle control valve is on backwards!

j/k dont know

feeling loopy today

[mk2vr6]

Anyone else have any ideas of what it could be?

[QuickTD]

If its a 1.9TD, the glow plugs shut off 2-3 minutes after starting and the lack of alternator load will cause the jump in idle speed. Not sure about the 1.6TD, perhaps the later ones were equipped with duraterm glow plugs and an afterglow function? I would just warm it up and reset your idle.

[jtanguay]

well actually i have a pretty good feeling it could be the residual fuel screw if you've messed with it...  its just coming back to me now.. i messed with it this summer and the idle would stay around 1400 or so... and be real sticky...  i think it sorta missed too, as in it wouldn't hold idle speed as well as with the stock position.

the diy in the faq to getting more power from your motor should have the residual fuel screw marked somewhere...  i dont know how to describe where it is...

pretty sure thats all your problem (if you or someone else has messed with it)

[andy2]

Your car has no automatic A/C idle boost as its a 92.Has Dr diesel upped the fueling a bit possibly?

[mk2vr6]

Not that I know of, just retimed the pump.

the fuel screw wasnt touched that I know of, but, since I bought the car, it was never idling properly.  The pump was retimed, and the car starts perfect in the cold but the idle rises up after a couple minutes to around 1200-1400 like it used to before it was retimed.

Im thinking it might be something as simple as the fuel screw.

Can I get a rough idea where it is on the pump?  and whats a good way to adjust it without breaking anything?

[burn_your_money]

Record whatever changes you make to your pump incase they make it worse, then you can easily go back.

[rabbitman]

I set my idle a bit high so it wouldn't vibrate at idle. When its real cold it idles so low it almost quits, 2-3 minutes later it idles up. I also turned the fuel screw all the way in and had to set the idle again, maybe thats why the idle changes.

The residual fuel screw on my NA is sideways above the metal fuel lines and towards the rear of the car. It has a tamperproof cap over the locknut. When you screw it in it'll rev up a bit. I don't know if it can hurt anything to set it wrong, it hasn't hurt mine, if you turn it out the car'll get way weaker. Hope ya can fix it.