205 Xu9J4 & Motronic 1.3, Spluttering When Hot, Codes 31 & 52

[Capago 0]

hey everyone, ive been getting really bad performance from my car over the last 2 days. prior to that i had the engine light on a few times on the freeway with no performance loss, then with no light on but lacking power and surging and today very heavily with the light on.

 

 

ive extracted some fault codes, the first being 52 - mixture regulation and 31 - mixture regulation auto adaptation.

 

prior to it running badly, id done the following:

-coil

-ignition leads, rotor, cap and plugs

-new rocker cover gasket

-spoox motorsport oil breather hoses 2 years ago or so, and their mi16 shortened inlet hose

 

since its been playing up ive fitted the following

-resealed inlet manifold and throttle body, all with silastic

-Bosch (direct fit) o2 sensor and new connectors - ecu harness end (as those pins were corroded)

-recently put on a plug lead cover, almost wondering if ive punched a hole in it from using the wrong bolts :/

 

disconnecting the sensor wires (blue connector) brings up code 51 which is the o2 sensor (as expected, replaced it because i gathered the ecu was getting some sort of a signal, and detected it had an open circuit, and thats why i replaced it) runs fine with the k light on and the sensor disconnected. the new sensor made no difference, ran like a bag of poo after 15 minutes doing a..."hillclimb" will only pick up on full throttle and sometimes wont even do that.

 

any help or suggestions would be greatly appreciated about to throw a haltech ecu at it if i cant sort it out

Edited April 29, 2012 by Capago

[welshpug 1,666]

if the wiring lambda and ecu temp are good then the only bit left is the afm really, the throttle switch doesnt do that much on these.

 

haltech certainly should get it running nicer

[Capago 0]

coolant temp sensor has popped up a few times, should note i had a VERY high idle speed of about 2500-2800 and its what...20 degrees C outside?

 

im having second thoughts on haltech, namely the sport 1000. i REAAAALY want antilag and i'll be kicking myself if i dont but wallet says no might have to go the sprint 500

Edited April 29, 2012 by Capago

[petert 601]

I wonder what a dealer would do?

 

Seriously though, have you checked continuity between the O2 connector and the ECU plug? It should be pins 10 (wire 10) and 28 (wire 141) on the ECU. Did you get the continuity correct? The shield should originate from pin 19.

 

Is there +12V getting to the heater element?

[Capago 0]

 

Seriously though, have you checked continuity between the O2 connector and the ECU plug?

 

I have the utmost of confidence in your wiring peter will check it out though

[petert 601]

But didn't you say you put new connectors on? If you got the wires reversed the ECU won't get the correct voltage from the sensor. It may as well be broken or disconnected.

Edited April 29, 2012 by petert

[Capago 0]

ive only changed the connectors when i changed the o2 sensor. a few weeks ago started running like balls and i hadnt changed it until yesterday. connectors are the right way around double checked that, did one pin at a time as well. checking voltages and continuity tomorrow when i have my multimeter at home

Edited April 29, 2012 by Capago

[welshpug 1,666]

antilag? you have a turbo??

[Capago 0]

ordering next month when wallet says yes lol might get the DP engineering package

[Capago 0]

ok so ive gathered the following via my test light and multimeter

 

12v at the heater connector, earth also ok.

earth at the earth pin of the o2 sensor

multimeter hovering around .55 (between .1 - .9v, should buy an oscilloscope..) for the reading of the sensor

checked the resistance of my coolant temp sensor, 690 ohms and slowly dropping as the engine warmed up.

 

but doesnt explain why its behaving itself briefly. probably knew i wasnt kidding about anymore. idle speed was about 1100 from ear, didnt look

Edited April 30, 2012 by Capago