Sudden 18-22 AFRs in 71 142 B20E MSII

[Antique Swedish Steel]

Hello
I am running fuel (no spark)MSII 2.25 with a v3.57 board on my 71 Volvo B20E. I am using an LC-1 WBS.
I have been up and running and developed my VE tables. A whole lot of fun after taking forever to get going.
Recently I was accelerating hard through second gear, and after I let up the motor started running lean (18-22 AFR). It would almost idle. It failed a block from my home and I coasted into my driveway.
Now the motor will turn over to 575 rpms and die. No amount of AE adjustments will keep it running. Warmup settings adjusted to richen the AFR seem to aid most with starting but noticeably drown the plugs with fuel.
Fuel Pressure is good, spark plugs were tan and turning black and wet after cranking. Fuel injectors are stock so I am running the PWM system. They measured 2.5 ohm across their terminals. All sensors are giving appropriate readings TPS CLT etc. Connections at relay board are tight. My O2 sensor output from the LC-1 was reading 5 V at the MS relay board with the ignition on. I reset the LC-1 along with sensor calibration. I made sure my setting and configurations in Megatune for the LC-1 are correct.
My questions are: What are the symptoms of a failing Bosch LSU4.2 sensor. I had read that sudden failure occurs with symptoms of steady 22 AFR readings. Would O2 sensor failure cause my problem?
Are there any other thoughts as to what caused the motor to run totally lean?
MSQ and Datalogs available.
Thanks
Joel
http://i214.photobucket.com/albums/cc72/glass004/NoStartB20Edatalog.png
http://i214.photobucket.com/albums/cc72/glass004/Summer2009119.jpg:cool:

[Morten VJ]

No The WB sensor isn't your problem.
You have fuel, do you have spark???
A failing ignition system, could explain your symtoms.

[chenz]

the engine should be able to start and idle without an o2 signal. Did you ever start the car without letting the o2 sensor powered up? Is it an LC1? Does it have that LED that flashes while warming up. Does it show any errors?

Have you tested for spark? If so and spark is present try spraying some airostart (ether) while cranking with your injectors unpluged the engine should fire. Because remember, testing spark your plugs out says nothing to wether you are getting spark under compressive conditions.

have you tried leaning off the warm up enrichments? The o2 sensor will read lean if too rich.

[Antique Swedish Steel]

the engine should be able to start and idle without an o2 signal. Did you ever start the car without letting the o2 sensor powered up? Is it an LC1? Does it have that LED that flashes while warming up. Does it show any errors?

Have you tested for spark? If so and spark is present try spraying some airostart (ether) while cranking with your injectors unpluged the engine should fire. Because remember, testing spark your plugs out says nothing to wether you are getting spark under compressive conditions.

have you tried leaning off the warm up enrichments? The o2 sensor will read lean if too rich.

The LC-1 and O2 are always powered up at starting. There are no LED error messages.
I agree that an ether test would rule out some ignition problems, but the way it was running prior to failure, and the sudden leaning out of the fuel, and the fact that my spark plugs were clean and tan at time of failure do not lead me to think it is an ignition problem. I'll do the ether test after church today.
Leaning the warm up enrichments prevent any starting response. Yes I have tried leaning off the warm up enrichments.
On starting datalogs, my AFR is either in the 8's or 20's but not inbetween at appropriate values. What event triggers the EGO system to display proper AFR values after starting?

[Antique Swedish Steel]

No The WB sensor isn't your problem.
You have fuel, do you have spark???
A failing ignition system, could explain your symtoms.

I have fuel on plugs after starting attempts, so I am getting fuel. Will try the ether test for ignition today, but as stated in prior post, I am not hopeful that is the problem.

Thank you for your responses.

Joel

[Antique Swedish Steel]

Well, I have ignition spark. The motor tries to run without ether but acts fuel starved.

Any ideas what to check. I think messing with the enrichments will not overcome my problem. I worked with that for hours.

The sudden onset of my problem would suggest a hardware/wiring failure?

Any ideas please?

THanks
Joel
http://i214.photobucket.com/albums/cc72/glass004/CIMG2129.jpg

[chenz]

Can you post a Datalog.

Is the car trying to start but not or just cranking when using only megasquirt?

Other than taking your injectors out and doing a flow test with megasquirt give it a run on your stimulator and to make sure everything looks ok. Maybe a test light on your injectors to see if the signal is still getting to them (we use an LED). Could you have burned out your injectors? Has the resistance changed?

You could also try setting your injector settings to High impedance so the injectors get full voltage for the length of the opening time. But don't put them under load because you will burn out your injectors. so no more than idle. If the car runs you have issues with your flyback circit.

What ignition set up are you running exactly? Do you have a coil off a working car you can use? What is the gap like on your plugs? Try 18 thou gap to see if your coil is not charging enough volts to jump the spark with petrol, but might with ether.

[Antique Swedish Steel]

Can you post a Datalog.

Is the car trying to start but not or just cranking when using only megasquirt?

Other than taking your injectors out and doing a flow test with megasquirt give it a run on your stimulator and to make sure everything looks ok. Maybe a test light on your injectors to see if the signal is still getting to them (we use an LED). Could you have burned out your injectors? Has the resistance changed?

You could also try setting your injector settings to High impedance so the injectors get full voltage for the length of the opening time. But don't put them under load because you will burn out your injectors. so no more than idle. If the car runs you have issues with your flyback circit.

What ignition set up are you running exactly? Do you have a coil off a working car you can use? What is the gap like on your plugs? Try 18 thou gap to see if your coil is not charging enough volts to jump the spark with petrol, but might with ether.

I attached an MSQ but downloads failed on datalog. I'll send via PM
I do not have a stimulator. I will try test light on injectors. I like the idea of testing with PWM settings, now I know how to start.
I am running a pertonix breakerless ignition in a NOS distributor with MS picking up signal from negative coil terminal. Coil is new and ballast resistor protected.
I will try plugs with18 thou gap (I run with 0.3 gap).

You have given a non mechanic some very good starting points to work with.:nod:
thanks Joel

[B-lennium]

I see you have the e-bay fuel pressure regulator, is it still working? i have the same but I'm not very happy with the membrane in it.
maybe its leaking

[Antique Swedish Steel]

I see you have the e-bay fuel pressure regulator, is it still working? i have the same but I'm not very happy with the membrane in it.
maybe its leaking

Correct you are. E-bay FPR, shiney and with a FP gauge.

I hot wired the fuel pump and the relay and ran the designated 46lbs pressure without issue. The pressure sure does drop after the pump stops. Is that the membrane leaking?

thanks Joel

[B-lennium]

no thats normal, have you checked while cranking?

[Antique Swedish Steel]

have you checked while cranking?

Fuel pressure is good while cranking as well

[Antique Swedish Steel]

Can you post a Datalog..
I ran a datalog of the motor running very lean, but keep getting an invalid file error message when I try to attach? Suggestions?



Other than taking your injectors out and doing a flow test with megasquirt give it a run on your stimulator and to make sure everything looks ok. Maybe a test light on your injectors to see if the signal is still getting to them (we use an LED). Could you have burned out your injectors? Has the resistance changed?

The resistance for injectors are all WNL of 2.5 ohm. Any idea what the specs are on the LED? My regular 12V test light was inconclusive hooked up to the injector plugs.

You could also try setting your injector settings to High impedance so the injectors get full voltage for the length of the opening time. But don't put them under load because you will burn out your injectors. so no more than idle. If the car runs you have issues with your flyback circit..
I set the PWM setting to high impedance 100%, time threshold to 1ms with no change.
I set the PWM setting to 16% (from13%) and time threshold at 1ms (from 0.9) and the motor started. I got a datalog of it running way lean. I suspect it was running on only on fuel injector bank based on Plug #1 and 2 smelled of gasoline but were clean, #3 and 4 plugs had evidence of burning fuel and running the engine. My relay board has 12V for each injector. How do I diagnose the circuit that grounds my injectors for injectors #1 and 2?


What ignition set up are you running exactly? Do you have a coil off a working car you can use? What is the gap like on your plugs? Try 18 thou gap to see if your coil is not charging enough volts to jump the spark with petrol, but might with ether.
I did the small gap thing with no change in effect on starting.

Well I think I am closer to the problem. Any more ideas please?
Thanks
Joel

[chenz]

An LED just like on megasquirt, with a 330ohm resistor inline on the anode leg (positive). But did you try the test light the other way around? It should work if you are getting power to your injectors. Remember the test light is polerised.

[QUOTE=Antique Swedish Steel;2646110}
I set the PWM setting to high impedance 100%, time threshold to 1ms with no change.[QUOTE]

Time threshold needs to be 25.4millisecons for high impedance (1millisecond for low impedance). but remember do not drive down the road if the car starts and runs with injector output set for high impedance injectors.

[QUOTE=Antique Swedish Steel;2646110}I set the PWM setting to 16% (from13%) and time threshold at 1ms (from 0.9) and the motor started. I got a datalog of it running way lean. I suspect it was running on only on fuel injector bank based on Plug #1 and 2 smelled of gasoline but were clean, #3 and 4 plugs had evidence of burning fuel and running the engine. My relay board has 12V for each injector. How do I diagnose the circuit that grounds my injectors for injectors #1 and 2?

change your pwm current limit to 30 or 40%. At 16% it sounds like your injectors do not have enough current applied to open them properly.

[Antique Swedish Steel]

An LED just like on megasquirt, with a 330ohm resistor inline on the anode leg (positive). But did you try the test light the other way around? It should work if you are getting power to your injectors. Remember the test light is polerised.

[QUOTE=Antique Swedish Steel;2646110}
I set the PWM setting to high impedance 100%, time threshold to 1ms with no change.[QUOTE]

Time threshold needs to be 25.4millisecons for high impedance (1millisecond for low impedance). but remember do not drive down the road if the car starts and runs with injector output set for high impedance injectors.



change your pwm current limit to 30 or 40%. At 16% it sounds like your injectors do not have enough current applied to open them properly.

<a href="http://s214.photobucket.com/albums/cc72/glass004/?action=view&current=CIMG2136.jpg" target="_blank"><img src="http://i214.photobucket.com/albums/cc72/glass004/CIMG2136.jpg" border="0" alt="MSII Wiring Harness and Relay board on B20E"></a>
I got the motor running with altered PWM settings. It sounded like it was running on two cylinders. A a few moments running Cyl 1 & 2 exhaust pipes were warm to touch and 3 & 4 exhaust pipes were to hot to touch.

I am getting little or no fuel from the injectors served by my # 2 injector bank.

I have a zipped datalog of this start attached and MSQ attached.

Is this the low impedence injectors damaged by the PWM or something wrong with my #2 injector bank circuit?

Where do I access the injector test mode function in megatune?


Thanks
Joel

[chenz]

Post not required.