167 replies to this topic

[The Batman]

what else could cause this? initially we thought it was a leaky manifold but after speaking to 2bular he reminded me of my last exhaust which was a slip on 4-1 manifold now my new one is a welded one... my afr is 10.0 on cruising speed and on idle (it wasnt before i took it for a constant 1hr 30min drive on motorway this has happened) if i unplug the lambda sensor it goes up to around 11.6afr is it a faulty lambda sensor? what is can i check

Edited by joe_589, 23 January 2012 - 05:35 PM.

[FLD]

Fuel pressure, tps, map, maf OK? You need an opcom to check it all.

[The Batman]

i got no error codes i have a spare map sensor so i can change that. i will get a new vxr maf sensor fuel pressure reg was modified by cms where is the tps sensor? the wierd thing was it was running fine until the motorway drive..

[Darcini]

Joe, I've got a spare known to be working 80mm maf sensor you can borrow to rule it out?

[vocky]

did you find the cause of the 'exhaust blowing noise' near the manifold that we heard then

[NickB787]

I have the same 4-1 slip on manifold they slip on but when heated seal very well can't be that. so an air leak is the most obvious answer. afr gauge being incorrect or maybe the wideband itself

[Exmantaa]

You engine should run 14.7AFR in a closed loop cycle with the O2 feedback, so start with the obvious and investigate your O2 sensor and for pre-sensor exhaust leaks. (And I thought 2bular did not do slip-on manifolds anymore, just because of these sort of O2 problems?) Can you check the voltage of the O2 sensor with a warm-up engine? Normally it should fluctuate around 450mv. (~900mv being rich, ~20mv is lean) If the sensor shows you a rich ~900mv at WB 10AFR, there's something wrong with the feedback loop. (wiring or mapping) If it's 450mv or lower and your WB shows a 10AFR, nothing wrong with the feedback but one of the 2 sensors reading is way off! (and maybe due to exhaust leaking fresh air in)

Edited by Exmantaa, 23 January 2012 - 06:17 PM.

[The Batman]

they dont do the slip on ones anymore and only do the fully welded ones now darcini i will pm you now what else could it be? its not a faulty AFR guage as you can blatently tell its over fueling. i will skank a lambad sensor of lee at the weekend

[Exmantaa]

Just take a multimeter an measure the bloody thing! 1 minute job, maybe 10 minutes searching for your multimeter.

[The Batman]

where do you check for voltage? which cables? i will check after dinner and before work

Edited by joe_589, 23 January 2012 - 06:32 PM.

[JG]

I reckon you still have an exhaust leak, or a faulty lambda.

[slindborg]

bear in mind that running rich like that can/will toast your lovely expensive LSU sensor

[Exmantaa]

I assume you still have the same square O2 connector as on the 2.2? You should measure between pin A (white?) and pin B(blue?) The 2 other (black?) wires are from the internal heating element. (Edit, checked colours on my O2 sensor, but yours may differ.) stick 2 thin needles or so in there from the back or simply push through the wires. Ow, and what was your AFR reading with just the ignition on ?

Edited by Exmantaa, 23 January 2012 - 06:42 PM.

[The Batman]

i have the rectangular connector but wires are probably the same only problem is does engine have to be warm?

[Exmantaa]

On my engine the O2 feedback starts already after ~1 minute, so after a few minutes you should measure something. Letter A-D are written on the connector at the wire end

Edited by Exmantaa, 23 January 2012 - 06:46 PM.

[The Batman]

cool i will get it done thumbusp

[FLD]

Joe, opcom can give you live readouts from all your sensors. Might be weird though having a tubby ecu on an SC engine though.

[The Batman]

can the scanguage? my laptop doesnt seem to like the cable i use to connect to the obd port... either that or op com on my laptop is crap!

[The Batman]

i got 1 black, 1 blue and 2 white which ones do you want the measurement from?

[Exmantaa]

pin A & pin B, so most likely black and blue. And scangauge should be able to pick this up to, if you know how...