rev spikes

[adamp]

Hi
over the last while my 06 zd30 150ks sometimes had little rev spikes.
sometimes i will start it and it will just rev to 2000rpm then just drop straight down to normal idle.
but today just sitting at the set of lights in first gear with the clutch in it reved to about 2000rpm and then just dropped back down to normal. just like if i gave it a rev my self.
my only mods are egr block and catch can.
any help would be great

 

[Rumpig]

Try a "throttle position sensor" relearn. Warm it up then let it idle for a full 10 minutes.

 

[adamp]

ok thanx I will try that. I did to a ecu scan by putting the to wires over the terminals. I did come up with throttle position, intake temp sensor and crank angle sensor. but I don't no how long them codes could have been stored for like im talking maybe years so I wiped the codes and I checked them yesterday after it did that weird thing at the traffic lights but it just come up with 0505 witch I understand is no codes
what elc could it be?

 

[Rumpig]

TPS is the obvious one, try that and check for new codes occasionally. Your right about 0505 = no codes.

 

[adamp]

yeah ok. I let it idle for over 10 min today so I will just wait and see if that fixs it

 

[tweak'e]

the other one is running on engine oil.
is the catch can to full ?
turbo leaking oil?
catch can making to much restriction causing turbo to leak oil?

they tend to put out most of the blowby at idle which can cause the oil to be blown in.

 

[adamp]

ive also done the butter fly mod.

I will say the catch can was close to being full but ive got a forefront catch can so I a got a pipe through the bottom of the can.
I don't think the turbo is leaking oil. when I did a service yesterday it did check the impellor and it seemed like there was no oil in there. I guess I have to take the intake pipes off to check for sure.

 

[adamp]

so for a few weeks it has been running fine. but today it started again. was idling through a car park today and it just jerked and engine light come on and the rev gauge was dead but engine was still running.
when I started it in wen I left after doing my shopping it did is rev spike again and then I drove into another car park gain and it did it again.
got home a checked the fault codes it come up with 0407 witch is crank angle sensor again.
does anyone no what it could be?
catch can is empty.
other than this is seems to be running fine.
I just don't no what to do.

 

[Rumpig]

Could be dodgy wiring on the C.A.S, corrosion in the plug, sensor may have moved.

 

[adamp]

ive got it booked into the mechanic on the 10th.

what its doing now also is the tacho will dropout and the engine light will come on. ill turn the car off and start it again then engine light is out and tacho is normal.
still throughing the code crank angle sensor though, no other codes.

what sensor does that tacho run off? crank angle? alternator?

 

[tweak'e]

tacho runs off the crank angle sensor.

 

[adamp]

yeah ok thanx. seems like I the crank angle sensor if the course of my drama. least I no I shouldn't be to expensive to fix.