Running Rich In Mempho

[Syclone1514]

I need some help. This is my first post for assistance. I am not a newbie, but certainly have a lot to learn. I have been trying to learn as much as I can about these bad boys from any source I can. Here go: the SY started running very rich the other day. Here is some background:

Stock internals, stock heads, stock ignition, stock injectors, Walbro 255, adjustable FPR, Air to Air, EGR block off, Innovate wide band, RPM stage 3 (recently installed) w/ stock down pipe and CAT, 3-Bar, Alky set to come on @ 6lbs boost. Just got TCS 9/11 2800 installed, and Ostrich and TunerPro RT over the winter. I am running a BBZB with EGR disabled, and 3-bar.

Life was good with the SY because I finally had these parts installed and it was time to start tuning and head to the track for some fun. I have had the truck since 96' and have not run it at the track. I decided late last year that this year that my son and I would have some real fun with it.

Here is where it all started. I wanted to move the ECU to the glove box and replace some old vacuum hose while I was at it. When I completed these two tasks and fired her up she was running very rich. It's like limp home city. Black smoke out the tail pipes, along with black crud. Checked all vacuum hoses. Wide band says 10.1. Wide band is standalone and not emulating narrow band. I did get a 44 code (lean o2) once. I visually checked all connectors on the ECU, and did a continuity check on all pins. I also did a continuity check on the narrow band - all looks good. I use TurboLink for scanner and it says narrow band is lean and not switching at all. Replaced narrow band with new Bosch (since narrow band was original anyway and needed replacing) - no change. Everything else checks okay with TurboLink as far as I can tell. My Autometer vacuum gauge says 19.5 lbs @ idle. My adjustable FPR is set at 50 w/o vacuum and around 43 with. I bumped it down to 35 - no change. Open loop, closed loop - does not matter. Unplugged narrow band for the hell of it and no code triggered. Hummmmmm! Continuity test says all ECU grounds are good.

Tomorrow I am going to run another ground wire from the narrow band to engine ground. I am also going to verify voltages on MAP, TPS, etc... I do not have another ECU to swap. Beyond this I am stumped.

I am hoping some of you guru's have some ideas for me. I would really appreciate it.

Thanks, Keith ......................anxious for boosin' in Mempho!

 

[SBNova]

Re: Running Rich In Mempho

If your scan says that the narrow band is reading lean, then thats probably a good indicator of why your engine is running so rich. Figure out why the sensor isnt working right. Check for 5v at the sensor, and check the return voltage and see what it reads with a digital volt meter.

If you have an ostrich, why did you move the ECM? Ive got an autoprom and it lives on the "shelf", with the ECM still in the factory spot.

 

[Syclone1514]

Re: Running Rich In Mempho

I'll check tomorrow. Thanks for your input.

As far as the Ostrich I did not want to leave it in when I wasn't tuning. I also have a Moates G3 and figured I would stack programs and run that way for daily driving. I have a couple of 3rd Gen buds that want my assistance with some tuning, so I will need the Ostrich.

I do have an update. I am getting a Code 12 and Code 43 very intermittently. These are not being stored, but TurboLink caught them. I have checked continuity from the ESC module to the ECU - looks good. I went ahead and replaced the ESC module today - no change.

Thanks again, Keith

 

[Syclone1514]

Re: Running Rich In Mempho

I measure 12V @ pnk/blk from ECU (ignition wire), and ~.38v @ Sensor signal at ECU (ppl wire). I measure no 5v reference signal, but schematic looks like 12V is correct.

I came up with another ECU today for testing - no change. I have tried multiple programs, and have put just the memcal back in by itself - no change.

It immediately runs rich when you crank it first thing in the morning. Could that be stuck injector? It leans out according to WB 02 when you rev it. Narrow band also will go richer when you rev it.

VERY FRUSTRATING.............

- Keith

 

[turbodig]

Re: Running Rich In Mempho

. I am running a BBZB with EGR disabled, and 3-bar.

Is this a typo? If not, that likely is your problem.
Stock-configuration chips won't run with a 3 Bar sensor.

In fact, there never has been a 3-bar stock replacement chip made, to my knowledge.

 

[Syclone1514]

Re: Running Rich In Mempho

Sorry, TurboDig - not a typo. One of the bin's I have tried is a BBZB that I modded in TunerPro RT. It was running fine until we moved the ECU to the glovebox. I have a couple of JWaller bins that I bought from him. These are 3-bar - same problem.

I know the fix(s) is going to be easy. That is why this is so frustrating. What could make it run so rich when it is cold and in open loop? Sticking injector(s)? Then when it warms up and goes into closed loop (and reading O2) isn't the O2 telling the computer it is rich? Bad O2? I just put a new Bosch in it.

Any help is greatly appreciated.

Keith

 

[SBNova]

Re: Running Rich In Mempho

I was talking about 5v for the O2 sensor, sorry. You said your ecm reads lean O2, yet the wide band is showing rich. That means the ecm is misinterpreting the O2 sensor signal somehow. If it wasnt getting a return voltage from the sensor, or if the sensor supply wasnt a full 5v then the return voltage would be less than stoich and shown as lean by the ECM, forcing the ecm to dump fuel.

I *believe* the O2 supply voltage is 5v, and the return should be reading about half a volt and oscillating between 0.1v and 0.8v- if its not, then something is wrong with the sensor or the wiring.

 

[Syclone1514]

Re: Running Rich In Mempho

Okay, there are three O2 wires. Ground, Heater, and Sensor. Is the Sensor supposed to read 5v with the key on? I plead ignorant to this one. I guess the real question is: how do I properly read voltage on the O2?

Thanks

 

[turbodig]

Re: Running Rich In Mempho

Sorry, TurboDig - not a typo. One of the bin's I have tried is a BBZB that I modded in TunerPro RT. It was running fine until we moved the ECU to the glovebox.

I can pretty much guarantee that anything close to a BBZB wasn't running fine with a 3Bar sensor. It might seem fine in places, but lots of things will be waay off.

I have a couple of JWaller bins that I bought from him. These are 3-bar - same problem.

I know the fix(s) is going to be easy. That is why this is so frustrating. What could make it run so rich when it is cold and in open loop?
Keith

Lots of possibilities there. Post a datalog with the 3 bar chip + sensor, start from there.

The moved ECM might indicate that you have some bad/loose connections, also. Spray some contact cleaner into each of the connectors and remove/insert a few times. They get green and ugly over time.

Later,

 

[turbodig]

Re: Running Rich In Mempho

Okay, there are three O2 wires. Ground, Heater, and Sensor. Is the Sensor supposed to read 5v with the key on? I plead ignorant to this one. I guess the real question is: how do I properly read voltage on the O2?

Thanks

Nope. Two wires are heater voltage, the sensor voltage will swing all over the place. It's pretty tough to put a meter on it and get a decent reading, it moves around too fast.

I've seen wide-band o2's lie quite frequently. (Particularly Innovate) Don't assume your wide is working right. Have you re-calibrated it in free-air lately?

 

[SBNova]

Re: Running Rich In Mempho

Does your turbolink show O2 voltage in real time? Start there, and check for a .1-.8 varying voltage. On a line graph, the voltage should oscillate up-down-up-down in a nice swoopy curve.

 

[Syclone1514]

Re: Running Rich In Mempho

I did do a open air calibration on the Innovate WB.

TurboLink does show real time O2 voltage. It hovers around 220mV

I will try to clean the connections.

Also, I put the 2Bar back in for testing - same result

Thanks again guys.

Keith

 

[turbodig]

Re: Running Rich In Mempho

I did do a open air calibration on the Innovate WB.

TurboLink does show real time O2 voltage. It hovers around 220mV

I will try to clean the connections.

Also, I put the 2Bar back in for testing - same result

Thanks again guys.

Keith

stock o2 volts at 220 mv all the time? Bad connection, or bad ground.
O2 ground is at the back of the driver's side head.
It should swing between 100 and 600 mv, lots of transitions back and forth.

I've had new o2 sensors go bad out of the box, also.

The ECM move is what makes me suspect a connection thing, though. The connections are touchy.

 

[Syclone1514]

Re: Running Rich In Mempho

Dig, Correct, always reading right at 220mV. Turbolink shows you a dynamic bar graph of the voltages changing from rich/stoich/lean and a dynamic readout of the voltage. Bad ground/connection was my original thought (and still on that one). I have checked continuity on all the connections to the O2. Again, I have run my own ground from the O2 to the engine. I got a replacement Bosch last night and will try this evening also.

I will try cleaning connections this evening when I get home.

Keith

 

[Syclone1514]

Re: Running Rich In Mempho

Again, I think I have two problems. Remember, it is extremely rich when I first crank it. It's in open loop then. Gas in the oil. I'm thinking stuck injector. If in fact I find a stuck injector should I go ahead and replace them all? If so, what injectors do you recommend?

Also, I checked again and the heater wire is connected 12v. I do not read 5v on the O2. Where am I supposed to read 5v? Ground is good, with separate ground to engine.

I'm not going to be able to work on it tonight, but I am on for tomorrow. I guess Thursday nite Test n' Tune at the Memphis Motorsports Park will not happen this week.

Thanks again. Keith

 

[SBNova]

Re: Running Rich In Mempho

I am home tomorrow. I will try to check the input voltage on mine for you to verify. I am not sure where I got 5v, it just sounded right- but I could be wrong. I will keep you posted.

220 is definately not right though. That voltage should cycle about every second.

 

[turbodig]

Re: Running Rich In Mempho

Again, I think I have two problems. Remember, it is extremely rich when I first crank it. It's in open loop then. Gas in the oil. I'm thinking stuck injector. If in fact I find a stuck injector should I go ahead and replace them all? If so, what injectors do you recommend?

Also, I checked again and the heater wire is connected 12v. I do not read 5v on the O2. Where am I supposed to read 5v? Ground is good, with separate ground to engine.
Keith

Heater voltage is 12v, not 5.

Is your fuel pressure regulator working right?

Does one plug look different from the others? That would support your stuck injector theory.

 

[Syclone1514]

Re: Running Rich In Mempho

Bummed. I have not had a chance to work on the SY. Long hours at work. Was hoping to get her repaired by the weekend.

 

[ashman]

Re: Running Rich In Mempho

Bummed. Was hoping to get her repaired by the weekend.

years from now...you'll look back on this post and :rotf:

 

[Syclone1514]

Re: Running Rich In Mempho

Bummed. Just did a leak down on injectors - No leakage. Put 2Bar and stock memcal back in - no change. Put in new Bosch 02 - no change. Checked again for vacuum leaks - no leaks found.

Here is what I found: The green connector on the back of the ECU- when I wiggle itwires just right I can make the truck die. Must be something with the connector. How do you get the pins out? Is there a special tool?


Frustrated in Mempho !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!