Dropped idle revs.

[superiorcruiser]

hi men,
just wondered what would cause the revs to drop at idle speed?
my 04 d22 used to idle at 750 rpm,and now its at about 600/650 rpm
the last thing i did was my 80 series air filter mod,and then it was fine and went like the clappers,then a little while later i noticed the change in idle rpm and a slight "shake: at idle and it also became a little sluggish at take of.
one place i rang said it might be a sensor...
any ideas?

thanks,
joe

 

[tweak'e]

egr stuck open?
clogged intake?

 

[superiorcruiser]

i have the egr mod done,so i supose its not that..

 

[Dave]

Pretty sure mine sits on like 700rpm or so idling.

Ill double check tomorrow when I go for a drive.

 

[superiorcruiser]

ok,dave..thanks..but like i said mine dropped a 100 or so revs from before.

 

[tweak'e]

could be just crap fuel. let it idle for 5-10min and idle should go back to normal.

 

[superiorcruiser]

this has been going on for a while,had quite a few tanks of juice thru it...
on a couple of occasions i noticed it jump back to its "normal" idle speed but stayed there for only a minute or so then dropped again..

 

[Goata]

Could it be the TPS?

 

[BP90]

Sorry to hijack the thread, my zd30 Nav is doing the same thing was idling up around 750 and just in the last few weeks its dropped to bout 600 with a slight shake at idle for a brief second or 2(although only noticed it on mine just after slowling down and stopping at a set of lights or stop sign). But yeah like superior cruiser i have had a few tanks of diesel through it and no difference made by fuel.

 

[superiorcruiser]

Could it be the TPS?

whats a TPS...where is it

 

[jap55s]

Diesels don't have automatic chokes do they..?

Sent from my iPhone using Forum Runner

 

[Goata]

whats a TPS...where is it

TPS is Throttle Position Sensor. Down near the peddle I believe

 

[tweak'e]

doubt TPS , tho not impossible, as they have an idle switch as well.

the ecu should compensate and adjust idle back to normal. however it may not do that if fault is to big (ie run out of correction) or that it thinks its at correct rpm (ie fault in crank sensor)

check the basics eg fuel, fuel filter, air filter etc.

 

[superiorcruiser]

can any of these sensors be cleaned or adjusted?

 

[tweak'e]

not that i know of. idle switch may be, but thats all built into the TPS unit.

 

[superiorcruiser]

just done an oil & filter change and also changed the fuel filter.
did the air bleeding on the fuel filter but i noticed that after i drive the car the plunger can be pumped 3-4 times and then it goes hard again.
it does it all the time.
is this normal?
all the fuel hoses(2 rubber ones) look ok and are tight,so is the fuel filter assembly..
is it getting a leak somwhere?

 

[tweak'e]

common place to leak air in is around the filter or the primer itself. the other one which sometimes comes up is the injector spill line which is the small hose on the inlet side of the pump inlet.
however 3-4 pumps could be ok, possibly anti drain back valve in the primer is not working.

the other way to check for air is to fit a bit of clear fuel line and look for bubbles.

 

[superiorcruiser]

ok,i will look for the injector spill line,if i know what to look for.lol.
how do i check the anti drain back valve?