Maxima Forums - Wierd Problem still step inside.

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Wierd Problem still step inside.

As you know from my previous posts that I had some issue runing really rich, where my engine would flood if my rpms dropped down even if I was in gear or not. I figured the culprit is a vaccuum leak somewhere so I checked all my piping etc etc sprayed TB cleaner and still didnt find anything but my idle got better now. When it drop it stops dead on 1000rpm and then like 2 secs later drops to around 700-800 and then after that it starts fluctuating between 600-800 rpm. I no longer have cold start issues but now when i tirn the car off and try to start it back up while its still hot most of the times it doesnt start. Now I know you guys said that the safc below 39% accel doesnt do anything and that the ecu will sorta tune itself to being stoich. With the low accel map off I am rich as a pig when driving and my car gets flooded. Now I dropped 17% feul from 1k to 3k and my car does the thing where it stops at 1000k then drops down to 800 or so then starts fluctuating. Without those corrections my car just gets flooded while driving when the rpms drop really low. Any ideas on whats going on? I though taht anything below 39% throttle the ecu would accomidate for and make it stoich. If you guys want videos of what im talking about I can grab a quick shot tomorrow morning. And even with 19% correction after 4000rpm it still goes on the rich side and my car starts to buckle because the engine is getting flooded im assuming. Any thoughs would be appreciated. Thank you.

I was just talking to steven88 about this and there is a post somewhere on the org (probably all-motor section) where it lists all the conditions for when the car is in open-loop or closed-loop operation. It's not just the 40% throttle condition that causes a switch between open and closed loop. Apparently there are a lot of other conditions/factors and as a result, "rarely" does the car operate in closed-loop, which explains why your SAFC corrections are actually working below 40% throttle. I still need to dig up that thread again and do some more research on this because I'm going with the SAFC or VAFC soon.

I just wanna fix the bish so i can put my new clutch in and let her rip..can you further explain this open and closed loop deal?

From this thread:
http://forums.maxima.org/showthread....oop+conditions

Quote:

Originally Posted by Kevlo911

Open Loop Control
NFEC0014S05
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
Deceleration and acceleration
High-load, high-speed operation
Malfunction of heated oxygen sensor 1 or its circuit
Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
High engine coolant temperature
During warm-up
After shifting from “N” to “D”
When starting the engine

From the FSM...

Malfunction of heated oxygen sensor 1 or its circuit especially interests me. Perhaps there is a way to force open loop operation always.

Is this still with both the stock and JWT ECU?

Pure guess .. dodgy fuel pressure regulator? Perhaps Coolant temp sensor?

What MAF do you have?

dont have an frp and its a z32 maf.

What direction is the harness on the Z32 MAF facing? Is it parallel to the ground or it is facing up or down?

leaky injector would be an easy guess

Mike how would I tell if its a leaky injector, without taking off the mevi? Is there a test I can do of some sort, I dont have a fuel pressure gauge, but I need to get one.
Ian= Its parallel to the ground