Running rich

[C.Gesler]

What would cause a rich running condition in closed loop but not in open loop
On first start up I have a clean burn (smell test) once ecu goes into closed loop I get a really rich burn
I know it should be something with O2 but harness and all check out

[Axel kain]

how can you tell youre laving closed loop issues while driving? tried just disconnecting the sensor to rule it out?

[C.Gesler]

It's more start up runs great at first then stays rich some tes when I really get on it it seams to be burning right then back to rich
M9stly I can tell during startup
I have un plugged sensor and dosent make difference
I started to swap to na2t did injectors and ecu was running great for a few days then again it returns to running rich

[Axel kain]

pretty sure the o2 is not in operation at idle... so youre running the wrong parts for the car, incompletely, well that explains your WHOLE issue right there.

[C.Gesler]

You are right about O2 maby I'm over thinking this problem
I was having this issue with the stock injectors and ecu
I changed ecu due to some burnt circuits. ecu, injectors and O2 match. Thought that would clear up my issue, and it did for a few days in fact it ran lean for a bit first (heard light pinging) probably running on the old cars sensors input)

Anyway just so I know, how would an 86 n/a run with the turbo ecu and injectors installed,

[les_joey_paul]

Make sure your components match. Make sure if you have a cali or fed ecu that it matches the yellow or blue tag maf.
At idle with the engine At operating temp it uses o2 feedback. The only time it doesn't use feedback is in open loop ( wot and cold engine) so at cruise and idle you should get to the 14.7 afr.

[les_joey_paul]

You are right about O2 maby I'm over thinking this problem
I was having this issue with the stock injectors and ecu
I changed ecu due to some burnt circuits. ecu, injectors and O2 match. Thought that would clear up my issue, and it did for a few days in fact it ran lean for a bit first (heard light pinging) probably running on the old cars sensors input)

Anyway just so I know, how would an 86 n/a run with the turbo ecu and injectors installed,

I ran my 85 like that and it drove rich for the 2 months before I finished the swap. I also had the incorrect o2 installed and plugged in. It was drivable though and shot much fire.

[C.Gesler]

Yesterday I double checked all parts
ECU is an 86 t fed 5sp
O2 is 17 mil titania
MAF is a yellow tag fed
Also checked
valve timing
Ign timing
New plugs (bcpr5es)
Wires (sti)
Cap (nissan)
Rotor (nissan)
Guess I should finish the rest of the swap and see where I stand at that point
I also dont run idle controls or emission related components

[C.Gesler]

Can anybody do an ohm test on their MAF as per xenon's site so I can compare readings
Thanks

[Augustus Maximus]

Have you checked the CHTS. You know the ECU enriches the engine base off the temp reading the CHTS provides. Bypass it with a 2.5K resistor and see what happens.

[C.Gesler]

New from nissan and I have rewired the harnes

[C.Gesler]

Tested MAF again. Between c-d I am getting 0 ohms instead of .9 so I'm guessing that is my problem, sence all other readings ar the same per xenonz31 MAF testing procedure
Anyone know if this is fixable or just replace

[C.Gesler]

Just opened up one of my mafs shouldn't c-d be 0 ohms sence they are soldered to the same tracer on the board