I have a 87 GTA with a new 350 stealth ram injection and 165 ecm 6E code and it is running very lean according to the int and blm's. I installed a new engine, same cam same pistons same heads just ported and last years engine tune to start off with. While at idle the blm's jumps around 128-140 and at part throttle it maxes out at 180 along with the int. I have adjusted the maf and scaler tables along with the inj pw vs batt voltage and the more fuel I put in it starts to run rough and stalls. The exhaust smells very rich so I pull fuel out and it seems to run better, but then the blm's and int shoot higher. I don't notice a misfire or anything but I will pull plugs out tomorrow after it cools down to see what they look like. Any other ideas to try, or what else to look for????

 

If you are running the stock MAF sensor you should leave the scalar alone untill you see that your lean all the way across the maf table.

How big of a cam do you have? If you have much lift and overlap its gonna show lean at idle and when you add fuel it will smell rich because it is rich.

At idle you should forget about the BLM and INT and tune it by the plugs.

I can't tune by the BLM, I tried and never got it right. In fact, I don't even have my n-b o2 hooked up at all, I run in open loop all the time. A w-b o2 is the way to go. I know, that another $200 but I will never again try to tune one without it.

 

WAY RICH conditions may fool the o2 to read lean to... So if it smells unburned fuel it may be overrichened and fooling the o2 sensor. How do your sparkplugs look like ?

 

Funny you mention that, my o2 sensor crapped out yesterday also, had to steal one out of my other firebird to continue testing. I am using the stock maf sensor, I did not touch it the fins and screens are still in tact. Here is the specs on the cam http://www.compcams.com/Cam_Specs/Ca...?csid=214&sb=0 and here is a pic of the BLACK plugs

 

Also what is the best way to adjust the fuel for this setup, mess with the maf table, or the inj pw vs batt voltage table or somewhere else???

 

Seems like youre overrich and it causing it to read lean..
Your sparkplugs are totally black..

Whats your fuelpressure ?
Stock Injectors ?

 

Fuel pressure is at 42 psi ish and I have 30 lb injectors.

 

With the BLMs/INT going to 180 along with the engine running rich (very), there is something wrong in the O2 sensor feedback. You can run open loop for a while to rough in the tune and get the car driveable.

As for the O2 feedback it can be the wiring. I've seen the O2 sensor wire melted onto an exhaust pipe, now that makes it run rich. It can also be a grounding issue between the exhaust and engine heads/block. It may also be that the ECM is not working correctly.

A cold O2 sensor reports lean, which will drive up the INT/BLM.

Try running it open loop for a while. Rough in the tune, if you have a WB can get the tune very close. Then look into the NB O2 sensor issue. The data logs will show whether the NB O2 is close or not. Can then go back to closed loop.

RBob.

 

Got the int and blm's down to 130 range and now the car surges very badly, can't let it sit without my foot ready on the gas pedal without it stalling. I adjusted the maf table#1 and #2 to get the blms better, actually added fuel and brought the blms and int down. Do I need to play with the maf tables more to get the idle better???? I also notive the lv8 while idleing on it's own for second or 2 hang around 80 or so and then slowly climb to around 110-120 and the engine starts to stall.

 

Here is a datalog using tuner pro of it trying to idle. https://home.mchsi.com/~kurtaarontin...loads/gta1.adl

 

Your prom how does it look ? have you set the injector constant!?
You when you got HSR you need to adjust the tables to make it run right...
Because it will flow much more then the stock intake.. So try adjusting the maf tables some and see if she runs better.. (Wich I think she will)..

 

I did adjust the maf tables, and then the idle goes to crap, surges and stalls, blm's and int around 130 ish, the injector constant is set at 30 lbs. The thing is I had this running great last year, rebuilt the motor and ported the heads and using the same tune and now everything is way off. Do you think the surging idle issues can be fixed with fine tuning the maf tables???

 

It seems to me that you are allowing the O2 sensor to run the engine rich. As I previously posted there is something wrong with the O2 feedback.

You believe it to be running rich, show spark plugs that are showing rich, as you add fuel it runs worse.

Go back to the stock MAF tables and disconnect the O2 sensor. Then see how it runs. Note that at this point the spark plugs probably need to be replaced (carbon fouled).

RBob.

 

I tried to pull fuel out and it wouldn't even stay running, had to keep the foot to half throttle, I checked all the wiring to the o2 sensor and I ohm'ed it and it checked out good. I added fuel and the engine ran, with less throttle, but the idle then started surging, it's got me totally confused. What else do I need to check for in the 02 feedback circut. I will unplug the o2 sensor and reset the maf tables to stock and start over that way.

 

To limit the fuel, try dropping the max intergrate and blm to 130 (or less) and leave the min alone. As you lower the max, the tune will get leaner, use this as a tuning aid.

In your data log the cells keep changing (4 - 10) and the blm's (128 - 148), dropping the max will steady out the feedback and help keep the engine running.

Move the cell boundaries (rpm and gr/sec) to stay in less cells, till the issues can be looked at.

The O2 mv are not cross counting till after 34 sec, and then stop again at 48/49 sec. Closed loop (intergrate) starts at 50 sec, and the blm update at 54 sec. With no O2 crosses the blm's will not be accurate.

On the attached graph, as fuel ms goes up, the rpms go down. The O2 does not follow the fuel, so there is no feedbck. All O2 mv are under .5 mv so ECM just keeps adding more fuel, cell 10 starts at 128 blm (53 sec) and is still rising to 148 blm at (100 sec).

Cell 4 gr/sec and fuel ms, are high for idle speeds should be 10 gr/sec 2-3 max.

my 383 idles in cell 0 at 8 gr/sec and 2 ms with 24# injectors @ 53 # FP
Cell 10 is 30 gr/sec and 2.5 ms this is my 55 cruise cell.

 

Ok I am finally able to do some more work on the TA and I disconnected the o2 sensor as RBob stated and fired it up. The car actually runs good off the stock arap chip in open loop. I then started to datalog and noticed the computer is reading 457 mv ish from the o2 sensor, its unplugged!!!! Is this correct??? I am going to recheck the wiring to the o2 sensor and make sure it is not shorted in any way and get back to you guys.

 

With the O2 unplugged 450 mV (or in that area) is normal. There is a bias in the O2 amplifier on board the ECM (hardware stuff).

Just give it some time. Run it open loop for a while. Then make a decision. Once it all runs decent open loop then try closed loop again. If it goes to heck-in-a-handbasket, you know then that it is an O2 feed back issue causing the problem.

Just give it some time in open loop first.

RBob.

 

Was able to drive it and it runs really well. At light throttle low load around 52-55 mph and I try to accelerate lightly and it starts to stumble and I then give a little more gas and it comes right out of it. I might run it some more and pull the plugs out again and see if it is rich or lean, and tune some more from there. Now I need to figure out why my autoprom keeps disconnecting me from data logging and emulating.

 

I hooked up the o2 sensor just to see how it loked while I was driving. I do have closed loop disabled and my blm's set to max out at 130. Car runs very good now letting it cool down to look at the plugs. I have a new datalog for you guy's to look at while I m driving. Keep in mind there is 2 sessions in this one, the first disconnects half way through.

 

Checked the plugs and they are a very dark tan, can still see some white on the porcelain. The electrode is a light tan to white. Still running a tad rich?? Also what else should I look for in the o2 circuit. The wire is not shorted to power or ground, this is my 2nd ecm, pulled it from my Camaro which ran good. Bad o2 sensor???

 

I usually watch the injector ms at certain speeds and loads (idle, cruise, and wot) to see if there are large differences. This would be a good check to see how close the open loop tune is to the closed loop. If the rpm, gr/sec (maf) and load are similar, then the injector ms should be close to the same.

Run the same roads and speeds (i use cruise control) any differences will show up.