redheddude222

iTrader: (4)

I have an 87 Turbo II with emissions delete, catless turbo-back exhaust, OMP delete, and an AEM wideband. It runs at a constant 11.2-11.7 all the time, regardless if it's at idle or cruising. I'm running the wideband in place of the stock O2 sensor using the 0-1V simulated narrowband. Fuel injectors were all cleaned and flow tested less than 1000 miles ago when I did the emissions delete. I can't find any vacuum/boost leaks when I hook up my boost leak detector, aside from the thermo wax hole on the throttle body (a quick search showed this to be normal).

What could be causing the car to run so rich? Any help is appreciated.

barkz

iTrader: (1)

sounds like you may be stuck in open loop? does the simulated narrow work? ive heard mixed things about them on these cars.

redheddude222

iTrader: (4)

I haven't had a chance to check voltage at the O2 wire yet, but it has worked fine in all of my other cars. I'll check that today hopefully.

Any other ideas?

WyomingTII

Leaky injectors?

redheddude222

iTrader: (4)

Not leaking. I took them back to the injector shop and had them re-test them. All good.

barkz

iTrader: (1)

did you check that simulated narrow band yet

DC5Daniel

iTrader: (10)

Why are you even bothering with the simulated narrowband? Any decent tuning solution would allow for 0-5V analog wideband which is going to be much more accurate and useful. Also the stock location is not idea for a wideband in the first place, you really want it further down stream.

redheddude222

iTrader: (4)

The stock ECU doesn't recognize 0-5V. I'm not looking to go standalone on a bone stock car.

I haven't had a chance to check the O2 output yet. It's been cold and drizzly the past few days and my garage is occupied.

welfare

yea that's definitely the next step. see what the ecm is seeing. backprobe the o2 signal pin at the ecm, as upposed to probing at the sensor. an open, or short will cause your symptoms. if you see high voltage, try creating a vac leak. see whether the voltage lowers to determine if the signal is accurate. however, you would think if the ecm saw high voltage, it would be pulling back fuel. just something to try though while you're in there. more info more better.
who knows. could be a bad ect sensor. i'd start checking your main inputs after detrmining o2 signal integrity

DC5Daniel

iTrader: (10)

I figured at bare minimum you would be using an RTEK, which does.

welfare

or just drill a hole in the dp and weld a bung on and run the wb separate. as mentioned, stock o2 bung isn't ideal placement for wb

redheddude222

iTrader: (4)

I am about to send the N332 ECU off to Rtek for their Stage 1 (remove fuel cut, disable fast idle). Their site doesn't say anything about O2 sensor voltages with this mod, so I'm assuming it will still read 0-1V.

DR_Knight

iTrader: (23)

Without 02 sensor plugged in car will run rich

barkz

iTrader: (1)

thats where the simulated narrow band comes in, but like I said in my first post, I dont think our ECUs like those

redheddude222

iTrader: (4)

Ok, so I finally got a chance to look at this. The wideband was outputting a signal, but the wire had come undone from the connector. I soldered everything together and now the ecu is seeing the O2 signal, but now there are other issues. The idle is low (~500 rpm), and fluctuates. Idle AFR stays steady between 13-14:1. When driving, it cruises around 17:1. Accelerating, it's a consistent 13.6:1 until around 4000 rpm, then it goes to 17:1 or leaner. Could this be caused by the simulated narrowband signal? I hooked up my TPS adjustment LEDs and only the one light is on, so the TPS shouldn't be the issue.

redheddude222

iTrader: (4)

I should also state that I have no way of reconnecting the stock O2 sensor. The wire broke off inside the harness loom and I'm afraid if I split the loom open I'll do more harm than good.

satch

iTrader: (1)

The oxygen sensor wire runs to pin 2D so you could always run another wire to or from that pin.

Does your car have the BAC because its role is to prevent the idle speed from dropping below 750 rpm.

redheddude222

iTrader: (4)

Yes it does, but I think the pins are pulling out of the connector. It seems to work best when I'm pushing it tighter against the BAC. The idle doesn't bother me as much as the lean air/fuel.

welfare

hmmm. i wonder if maybe your secondaries aren't firing. that's close to when they should kick in. may wanna backprobe and see if they are at higher rpm

welfare

also, you should backprobe the o2 signal at the ecm with the vehicle running. fog in propane through the intake tract. use a portable torch. see if the voltage reads full rich. then, create a large vac leak. big enough to just about make it stall. see if voltage goes lean. that's a quick and easy range test

redheddude222

iTrader: (4)

Is the stock O2 sensor output linear or non linear? I couldn't find anything when I searched. I know that the AEM's 0-1V output is non linear.

welfare

whenever i've scoped o2 signals they were always linear

redheddude222

iTrader: (4)

That sounds like my problem then. I'll have to pick up another narrowband and run the wire and see if that cures it.

redheddude222

iTrader: (4)

I picked up a new stock O2 sensor and ran a new wire to the ECU and it runs almost perfect. The only remaining issue is that it surges when trying to hold a steady speed while driving. I'm attributing that to the TPS needing some fine adjusting. I just wish there was a way to do that without removing the intercooler.

welfare

intercooler really only takes a few minutes to pull. you can remove the mounting bolts and loosen the clamps prior to bringing the engine up to temp. that way it'll just slip off when you go to check/adjust tps. it is paramount that the tps is adjusted with the engine up to temp. so accessing it must be done as quickly as possible