HELP!!! Poor idle, good drivability... new logger

[flaatr]

This is probably going to be long thread as I come up to speed with the intricacies of the the 1G but I've got a few questions/problems that I'm hoping you all can help me with.

My 1G seems to start and idle beautifully until it is warm at which point it begins to run a little rough, in my opinion and in comparison to it's cold and warming up idle. It drives fine. I recently got my logger running again and I'm not sure what I am seeing... My wideband is partially installed so no AFRs yet. I'm hoping with a little guidance I can understand the system and solve my problem. I've only fiddled with the logger a bit and I'm new to tuning the 1G... currency I'm just doing maintenance to a basically stock setup.

To be clear I am using MMCd v1.8g on a plam... the car is a '90

There are two O2 values, O2-R and O2-F... what's the difference and which should I look at. The 1G has only one O2 sensor so this is confusing.

I looked at OILT and it jumps around... something like 0-2 up to 130'ish. Is this normal, does the logger not read this vaule or does this indicate a problem with the sensor/wiring?

What is the PUMP voltage represent?

If I was to create a log to post for you experts to look at what values would you want me to record?

Thanks in advance for any help you can provide...

-Raffi

 

[navyissuedsm]

It sounds like you are having a possible closed loop issue. When the car warms up and leaves closed loop, the it starts to use different all the sensors and tries to monitor all the input signals instead of running off a pre-set series of parameters. Could be anything from a bad O2, to a intake temp sensor thats bad or even a bad TPS or ECT.

I have a DVOM we can use to test your sensors with if you don't happen to have one.

 

[haddixjl]

DVOM? Sorry for the question but what exactly is that? I have a 91 that I am waiting to start working on that hasnt been running for a while so any trouble shooting tools I may need, I am trying to read up on. Like pulling codes and stuff

 

[flaatr]

DVOM is an old term for Digital Volt Ohm Meter, most call them a DMM these days for Digital Multimeter.

Yeah, clearly something is going wrong in closed loop. I ran a log.last night and everything looked and sounded perfect during cold start and warm-up... after the car was warm I blipped the throttle and when the car came back to idle all bets were off. Trims stayed constant but the O2 kept jumping from 0v to normal and a few other parameters also went from stable to unstable. I'll post the log shortly.

-Raffi

Log file... (with almost everything on)
Throttle blip where things go wrong at row 935 (10/30/2013 5:01:33)

 

[flaatr]

Ok, so nothing yet...

Is there a way to test the idle switch response? Electrically the switch works but I'm not sure if the signal is getting back to the ECU. Out might have something to do with the open loop condition ignoring it or it might not be functioning but the idle does not change when this connector is open or grounded.

-Raffi

Can the logger sense this?

 

[flaatr]

Still could use some help or advise...
-Raffi

 

[wolf alchemy]

We only have OILP on our cars. There is no OILT going to the ecu. So that's why its spastic. Also. When you have KNCK make sure the timing retards. If it doesn't that's probably not a good sign. But the KNCK has to be higher than 5 to affect timing.

 

[bmxfelon420]

You shouldnt be getting knock under normal conditions, I'd start checking sensors. I'd replace the front O2, and see if you can log what the coolant temp sensor does. That's a big cause of issues on these cars.

Also you asked about the idle switch. You'd need to look at a wiring diagram to see what wires actually go back, but another thing to keep in mind is if you ever get ECMlink there's an option to simulate the idle switch from the TPS. That can come in handy sometimes too. It also gives you more logging options than is reasonable.

 

[born2race]

The log is kinda confusing but from what I'm reading the o2-F which I'm assuming is the primary o2 sensor, which is the sensor in the o2 housing. It doesn't look like it's cycling, but it's actually staying at 2.67 volts, which most likely leads to saying ur o2 sensor is shot. Start there, the o2 sensor is key in closed loop.