Ok since engine rebuild my idle isnt nice ...

 

you can rev it but then its up and down with in 100/150rpm

 

will tell you what i have tested and replaced

 

Tested 3 Maf's with and with out silien kit

Replaced Idle Control valve

no vac leaks tested up to 25psi

changed spark plugs for warmer ones

all connections are spot on

Timing Belt is spot on

15btdc pin 44 shorted

TPS 0.44

Base Idle done

Complete EGR Delete

 

 

just not sure ?

Edited June 22, 201213 yr by MarkDerby

have you tried resetting the ECU? or checking for codes?

yep done that and no codes ...

Check the tps voltage (0.44v) and that the connections good. If you need to set the tps then pull the plug on it for 10secs while engines running then plug back in.

Have you deleted the EGR Mark?-If not check the valve isn't stuck. You can also try disconnecting the O2 sensors see if the idle changes.

If you take off the iac connector can you adjust the idle with the screw?

http://www.300zx.co.uk/forums/showthread.php?162350-His-and-hers-diary-lol

 

 

now i know who this is about :lol:

TPS is 0.44

Done Base Idle

Compete EGR Delete

the only thing i haven't tried is O2 sensors

its possible for one to of packed up seems that the old engine dumped 3>4lt oil though the exhaust/intake system

Edited June 22, 201213 yr by MarkDerby

We put a pair of new O2,s on mine years ago and it hunted on tickover , i just disconnected them and all was well :confused1:

lol ok will try it tonite ...

 

if they need disconnecting I'm not bothered as the Tuning

will be to aggressive for them to work correctly anyways

Have you checked your vacuum caps are in place?(there may be a few if you have deleted stuff).......i lost a blanking cap off the balance bar and that caused a hunting idle, fitted a new cap and all was well again.

 

Edit.....just noticed you checked for leaks.......what plugs you got in it?, as I had a lumpy idle issue with ngk iridiums in and was advised by Jeff and a few other people to change them for standard plugs and that sorted it out straight away.

Edited June 23, 201213 yr by Rebel Scum

all present & no vac leaks Tested up to 25psi

Ngk iridiums?

yes ... 6's and 7's ... and some Normal NGK all the same

It could be that it needs running on the road for a bit and once the engine has bedded in a bit and the ecu has relearnt its settings it may settle down.....just a thought :)

its done 350 miles all ready the ECU only takes about 50odd miles to do its relearning

 

its quite confuzing as i have checked everything and swopped a few things over to test

 

i have another ECU chip and going to try unplugging O'2 sensors

Dont forget though that the engine will be tight (new bearings, pistons etc etc) plus if you have fitted uprated turbos and altered the fuelling with bigger injectors and ecu chip (cant remember what youve done to it) it may be that a lumpy idle is the trade-off for higher performance higher up the rev range.i know from experience that a lot of tuned engines suffer from a fluctuating idle which can be very hard or near impossible to cure.if it fluctuates by 100 to 150 rpm then theres something up with mine as it does that too when its warm but then again my v6 calibra would fluctuate by that much when that was warmed up as well.

yeah i get what u mean ...

 

will take a look at a few things later

taking it to Jeff on wednesday to put it on consult

check it over with timing & electric timing

 

the turbos was on the car before engine went pop

but didnt have idle problem

 

but like u say

 

Diffrent

engine

injectors

MAP

Did you adjust the idle air valve on a diagnostic? datascan ? adjusting the screw alone with no visible reading will be hit and miss. You are looking at an idle air reading of 15% again with the plug off the top of the valve while adjusting, then plug back in for the ECU to take over the tickover.

Did you adjust the idle air valve on a diagnostic? datascan ? adjusting the screw alone with no visible reading will be hit and miss. You are looking at an idle air reading of 15% again with the plug off the top of the valve while adjusting, then plug back in for the ECU to take over the tickover.

 

nope .. as my software is limited ... disconected plug set idle to around 800rpm then pluged it back in

lol ok will try it tonite ...

 

if they need disconnecting I'm not bothered as the Tuning

will be to aggressive for them to work correctly anyways

 

I ran mine for years in standard form with no O2,s at all , never had any issues !! wierd

nope .. as my software is limited ... disconected plug set idle to around 800rpm then pluged it back in

 

Base idle for a manual tt is 650 rpm with the yellow block connector removed from the idle valve.once its set at 650 rpm plug the connector back in with the engine still running and revs will automatically pick up to around 750 rpm as the ecu takes ov er control of the idle speed :)

ok will try that again tonite

ok disconected my o2 sensors and redid my base idle and still all the same

 

going to check my timing belt timing would find it hard to get it wrong as

it was all aligning up with the markers on belt and with markings on the engine its self

Maybe worth checking your ignition timing also.

Sounds like it maybe borderline and the ecu is tyring to over compensate.

ECU electric timing is set to 15* by strobe light and in consult

ok been and checked my timing again this morning and all is Spot on ...

 

heres the pics