I have fitted my supercharger to a 2.0l zetec. and plumbed it all up but it has a very erratic idle. with the throttle fully shut it still idles at
1000rpm- 1700rpm rather than stalling. I have checked for leaks without any joy.
My setup goes
throttle valve
short pipe
eaton m45 supercharger
couple of silicon pipes
chargecooler
couple of silicon pipes
inlet manifold with MAP comming from it
injectors
engine
running on megasquirt ECU. Do I need an idle stabilisation thingy and how do they work, or have I missed something. The thing I dont understand is
with the throttle closed where is the engine getting air to run from?
Any ideas?
have you got an idle controll valve?
quote:
Originally posted by theconrodkid
have you got an idle controll valve?
I think I'm right but don't quote me
The idle control valve has an independent air intake, usually plumbed into the intake pipe behind the air filter. It completely bypasses the throttle
body and produces a stable tickover.
Looks like you might be wanting one then 
XE's run an ICV and they aren't forced induction so may not be that.
Is your FPR running with a vacuum connection into the charged part of the system.
Fuel pressure is proportional to boost, although on a NA car clearly this doesn't change, so you'll need to check how its plumbed in as
standard, it may need modifying to allow for the larger amount of air getting in.
Does the charger have a clutch on it? ie. at idle is it actually producing any boost at all?
What map are you running on the MS? One for a standard Zetec or a S/C one?
If your idle control valve intake is on the non presurized side it would make a difference I would think.
Could be wrong- I have to hook one up to mine since I have up sized my throtle body.
Dale
quote:
Originally posted by the_fbi
XE's run an ICV and they aren't forced induction so may not be that.
Is your FPR running with a vacuum connection into the charged part of the system.
Fuel pressure is proportional to boost, although on a NA car clearly this doesn't change, so you'll need to check how its plumbed in as standard, it may need modifying to allow for the larger amount of air getting in.
Does the charger have a clutch on it? ie. at idle is it actually producing any boost at all?
What map are you running on the MS? One for a standard Zetec or a S/C one?
OK, so the S/C is running all the time, sticking in more air and also more fuel due to the higher fuel pressure.
You running any lambda input to the MS? Or do you have any lambda gauge etc?
Is the tps setup OK so MS knows the car is at idle and not partially open throttle?
Lambda would be good to know to see if your map is close given the S/C and different fuel pressure.
Is the engine speed steady with a fixed throttle position?
hi,
the lambda gauge is reading lean. But I wouldnt have thought it would cause this erratic idle. Looking at megatune the revs are actually going
from 800rpm up to nearly 3000rpm and smoothly no coughing or backfiring and a nice whirlingg noise from the charger
I'm not using tps i'm using MAP although the tps is wired in and working in the real time display. I think its only used for clear flood
mode. Maybe I should be running tps instead of map, i dunno.
....oh and I cant seem to get a smooth idle at any rpm.
ive never dealt with a blown engine before but idle valves are always moving and keeping idle stable,not having one is prob the problem.
it by-passes the completley closed throttle plate
quote:
Originally posted by theconrodkid
ive never dealt with a blown engine before but idle valves are always moving and keeping idle stable,not having one is prob the problem.
it by-passes the completley closed throttle plate
is there any pics of the setup
quote:
Originally posted by Monkeybasher
So are these idle valves ECU controlled then. Do I need to get one off another car and wire it into megasquirt?
Monkeybasher,
Any pics you can share??
they are ecu controlled,i have some ford ones laying around i think if your stuck
If you don't have an idle valve, and the engine continues to run with a completely closed throttle then you must have an air leak somewhere.
I think in amongst folder I got with my ECU it said boosted engines were best run on TPS at idle switching to map when you open the throttle.
quote:
Originally posted by Dusty
I think in amongst folder I got with my ECU it said boosted engines were best run on TPS at idle switching to map when you open the throttle.
Personally it soulds like a leak on the vacuum side - but might also be due to the fact that the TPS has been disconnected from the system and MAP
settings have changed due to the charger running from idle.
So I would start by looking for leakson the vacuum side and re-calibrating the MAP sensor. Alternatively try running both MAP and TPS - this should
give smoothest ride and best fuel economy - not sure if the Megasquirt system allows this kind of setup?
Alsomaybe consider changing to MAFsensor in stead of MAP - if you can only do MAP or TPS or MAF, then MAF is my preferred setup.
Hope it helps some
oops
After checking, double checking and checking again all my pipes/plumbing for leaks as everybody keeps saying it must be a leak including myself, guess
what, it was (the echo of "I told you so rings out" ) . I'm feeling a bit embarrased, but relieved. The leak I never noticed was a
hole on the actual supercharger, not sure what its there for. I plugged this and theres a shock it ran so much better. It was still crap revving up so
added lots more fuel and its getting lots better. Time for a coffee then back out.
Thanks everybody and stop shaking your heads.
I will post pictures tonight.
Thanks
Steve
[Edited on 29/5/06 by Monkeybasher]
May be an idea to find out what its there for at some point too 