Setting a constant idle?

[306Puggy]

I am finding that my cold idle and hot idle are very varied. If I set my cold idle to be reasonable so it doesn't shake it's tits off if I don't put my foot on the throttle then when the fuel pump has warmed up it is idling about 1300 rpm which is really annoying. I am still running the cold start spring but have cut the cold start cable off the wax thermostat because it was too long (I had a Lucas pump originally). I have tried using both the vertical idle screw and the horizontal one, neither can seem to get a consistent idle. I am still running the cold start spring inside the pump as well. I have changed the fuel filter which helps to get the cold idle closer to the hot idle but there is still a difference of a couple hundred rpm.

[Piggy]

if your not using the wax stat then you wont get the hot/cold control!?!?!!!!

[cwspellowe]

Wait.. confusing post is confusing. For a start, there's supposed to be a difference between hot and cold idle, that's why you can adjust them independently. Secondly, if you've removed the stat cable you're removed the pump's ability to change its idle to what you specify when warm.

Are you on veg by any chance? As I have a higher idle after a couple of minutes and my idle control has been removed. Darren explained it a while back but can't find the thread, the idle DOES change slightly by itself but is exaggerated by veg.

[Piggy]

yeah.
it will natrually rise once warm.

I have no hot/cold wax adjust. It starts at about 750rpm then rises to 900ish once warm.

if you have removed the wax stat, you cant expect it to change and adjust the hot/cold

[Dave]

You will find this is not actually cos your car warms up its just your alternator stops pulling charge.

[Seb_Ryan]

All I got out of that was something about a cow and alien having a rude time and a hybrid ginger being born..

Seriously, youve removed hot/cold cable so wont be hot/cold now, just somewhere inbetween.. if ya on veg I found itll idle higher than on derv

[306Puggy]

Wait.. confusing post is confusing. For a start, there's supposed to be a difference between hot and cold idle, that's why you can adjust them independently. Secondly, if you've removed the stat cable you're removed the pump's ability to change its idle to what you specify when warm.

Are you on veg by any chance? As I have a higher idle after a couple of minutes and my idle control has been removed. Darren explained it a while back but can't find the thread, the idle DOES change slightly by itself but is exaggerated by veg.

Yes, I am on veg and I removed the stat cable because it was slack anyway because it was a Lucas originally. But I am not sure about the hot and cold idle screws being different, if you look closely at the back of the pump they actually control the same rocker arm.

At the moment it shudders when it is cold and idles low and quietly unless I put my foot on the throttle to bring the idle up to a decent amount.

You will find this is not actually cos your car warms up its just your alternator stops pulling charge.

Woah, I thought it was because the pump gets hot and therefore preheats the veg slightly. I had no idea about the alternator thing.

[bigcheez2k3]

Doesn't matter if it was Lucas or Bosch. My old car had the conversion and we used the same wax stat cable.

[andywhy]

Alternator load shouldn't vary your RPM by more than 100rpm tops, and it's less noticeable at higher RPM because there is less noticeable drag. When the glow plugs turn off, that's when you'll see (and hear) a difference. Everything else shouldn't bother it.

[ginge191]

Yes, I am on veg and I removed the stat cable because it was slack anyway because it was a Lucas originally. But I am not sure about the hot and cold idle screws being different, if you look closely at the back of the pump they actually control the same rocker arm.

[Tom]

Just set your idle via the hot idle screw, and it should stay at that. Mine does, start up cold its about 1000rpm and when its warm it drops to 900rpm and stays like that. If your running lots of max fuel the pump loses its ability to regulate the idle according to electrical load or something like that!

[306Puggy]

I don't understand why, but it is not staying like that. I am using the hot idle screw to set the idle. That was what I meant by the vertical screw. If I start it in the morning the engine dies if I don't get the revs up by pressing the throttle. I really can't understand it TBH. Are you running without a cold idle cable as well?

[Anton]

Just take both the idle screws out.

[306Puggy]

Hi Anton. I can't see why that would help? I think I must have tried that awhile ago but even on max fuelling it died if I didn't keep my foot on the throttle.

[Anton]

I haven't used them in about 18 months. Mine idles cold on veg at about 700, then warm about 850-900.

Take a picture of your pump please, straight ahead and left side looking at it.

[306Puggy]

Sure bud! Front of pump:



Left side of pump:

[Anton]

Hmmm yeah may aswell take that idle screw out, not doing anything. What boost are you running? Also id unscrew the lda a bit more, help with off boost fuel. Have you taken the washer/spacer out too?

Looks as though your at the point where you need to move the throttle arm.

[306Puggy]

I'm running 25psi, fuelling turned 1 turn down from max. I have taken the white collar off the ground LDA pin and I have moved the throttle arm on the sliding bolts. I will try giving it more offboost fuelling then.

[Anton]

Hmmm have you tried upping the boost? The only thing i can think of is like I've said, take the throttle arm off and move it. If not could always turn the max fuel down a tad...