got a problem at idle

[Ed_RX7]

Got a problem at idle.   All of a sudden two days ago the car seemed to be missing and holding back. Had the leads and plugs changed...(even though I paid a rx7 specialist to change the plugs whilst I was on holiday..only to find out today that they had not been changed at all!!!!!)  Not "F" ing happy I can tell you)..quite a bit better but now I have an irregular lump at the bottom end. Idle goes from 750 to 1000rpm in milliseconds every ten seconds or so.....When driving lets say for example at 2k you can see the tacho jump from 2 to 2.5 k but with no increse in engine speed:confused:

Anybody had a problem similar?

Thinking it might be a dodgy earth....could this cause it?


P.S no loss in power at all and no smoke or loss of collant.

P.P.S  Not sure if its the map coz when the irregularity occurs ( ie jumps) so does the injector duty.

Am I right in thinking that the ECU is telling the car it needs more fuel  hence the jump in RPM?!!!:rolleyes: :confused: :mad:


HELP!

[Andreas]

maybe go to the shop and tell them you want new sparkplugs and did youn leave the car there?
did the problem occur far after the visit to the garage?

[Ed_RX7]

Andreas,

I happened about 3 weeks after my car 3was picked up at the garage....I\'ve got a feeling its my LIM gasket that is playing up

[bnaellis]

Hi Ed,

How do you know you injector duty cycle? do you have a apexi ecu with commander ? could be a variety of things but sound more like vacumm pipe not connected.

rgds

[Ed_RX7]

Yep got both.

Have been speaking to geff at reworx and he seems to think its the LIM gasket blowing.....done some checks with the old ECU and everything seems to piont to that.


Turbos out job i\'m afaraid.....:mad:


wish it was just a vac pipe:(

[bnaellis]

Ouch pretty expensive vacuum leak.
The paper gaskets are know for unfortunately but atleast you\'ll have a metal one to replace it and won\'t have to worry about this issue again.

rgds

[JayDee]

I would sort out the electrical problem first?
A bad earth or weak battery voltage does strange things on these cars.
Has your idle rpm changed at all?

Jason

[Ed_RX7]

do you mean does it just bounce between two points?

[Ed_RX7]

jay

What seems to be happening is that the ecu thinks it needs more fuel because of the air leak hence the uneven idle.....i think.

As i said when the idles fluctuates so does the injector duty....it keeps trying to correct itself.



Does anyone know if this would cause a kickback when trying to start the car?

[davefrith]

make sure you get both gaskets replaced while the turbos are out

Dave

[Ed_RX7]

didn\'t know there were two....what are they called i know the LIM gasket:confused:

[davefrith]

two turbo\'s two gaskets I thought .........

[JayDee]

In the pfc have a look in the ETC setting Then sensor on this screen on the bottom left is the 02 voltage, this should show you if the car starts running lean, then adjusts its self by upping the inj duty cycle. (closed loop).
Also do you have an air pump, I set the idle slightly higher without one, also what is the idle set to in the PFC compared to want you get?

Jason

[Ed_RX7]

720 on PFC...norammly constant...until all this....no Air pump.....all settings are catered for in the PFC....so thats covered.

Has anyone got a picture of where the LIM gasket is....not sure i;ve got the right place.

[Ed_RX7]

Confirmed that i have a metal head gasket......can these still Blow?