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Wtf?

Bill Blue

Platinum Level Sponsor
Yesterday, I decided to do some tuning after finalizing the intake manifold setup. Tuned it from 2,000 rpm down to idle. Mostly was running rich, especially 1500 and down. Got it running very good, a little on the lean side except at high manifold pressures. Idle was about 800 rpm and Lambda varied from high .9's to 2- something. Throttle tip in was very good, better than it had been in a long time.

This afternoon, I started it up to move it to the basement entrance to trial fit the Parish top I am modifying. Idle was very slow and poor. It would not take fuel. Made a data log, it was running at about 400 rpm (and lower) and Lambda's were .77-.80. I've never see them that rich. So, 3 hours later, after much data logging and adjustments, it was running at 800 rpm. After turning the idle screw in about a half turn (it is now idling at 1% throttle) and leaning out the entire bottom end about 5%. Throttle tip in is okay, but not as good as yesterday. Took it out for a trial run, it seems the 2000 rpm tune is still okay.

Its not like this is anything new. The rule of thumb is, the better it is running after a tuning session, the worse the will run the next day. I was hoping the manifold would cure that.

The bad part is this is exactly what was happening when I was tuning the Weber on the Pinto 2.0. Run fine today, like crap tomorrow. I thought the switch to EFI would put that behind me.

Bill
 

Bill Blue

Platinum Level Sponsor
Thursday, we took the car out for a 175 mile drive. Ran very well, but after about 125 miles I noticed a lean surge at about 1500 rpm. Later it turned into a cough. So I spent some time last night returning some of the 1500 rpm fuel that I had taken out. Added some more this morning, I would guess that about half that was removed has been put back in. Looking at the most recent log, nothing makes any sense and it runs like crap. Conditions that produce a Lambda of 3.333 @x millisec injector opening will, a few seconds later, produce a Lamdba of .89 at perhaps a slightly shorter opening time.

Time to get away from it.

Bill
 

Bill Blue

Platinum Level Sponsor
You watching your fuel pressure?

Is closed loop lambda control still turned off?

Not continuously monitoring. I suppose that is next, about 6ft of 1/4" hose is all I need. If it is the fuel pressure, I don't have a clue as to how to address the situation. This is the 5th fpr and I can't see how pressure would affect such a narrow rpm range. But there is a world of stuff I don't know. Wednesday, the pressure looked fine and pressure on the return line was too low to measure.

Yes, I've been running open loop since our conversion about how the closed loop calculations are made.

Bill
 

RootesRacer

Donation Time
Well when the same pulse width or less results in a richer mixture (or vice versa), you have to ask yourself what is the physical explanation for such a paradox.

Either the injectors have a mind of their own, the fuel pressure is not constant or your AFR meter is lying to you.
 

sunbby

Past SAOCA President
Donation Time
I can't see how pressure would affect such a narrow rpm range.
Bill

Not saying this is your problem, but I think it is possible that certain rpm's could create standing waves in the the fuel rail causing pressure fluctuations in a narrow range. Probably pretty rare, and I'm not up on the rail design properties that cause or prevent it.
 

Bill Blue

Platinum Level Sponsor
Okay, pressure gauge hooked up. 42 psi with key on, engine not running. 32 psi at idle. These are the same values I got the other day when it was pig rich and I leaned it out. Took a 10 mile drive, the pressure is very responsive, usually between 35 and 40 psi while on the road.

What do I look for?

Bill
 

Bill Blue

Platinum Level Sponsor
I'm taking the lack of response as an "Okay".

But I have noticed what I think is an anomaly. The "Aux Input" voltage varies. I had noticed a 2.16 with the sensor wire attached to it's relay, but with the circuit deactivated by removing its fuse. Yesterday, with the cap off the relay, the value was .9. This morning, within a minute or two, it varied from .01 to .4 with the relay cap off. What is the expected range?

Yesterday, we drove 135 miles. For the first 2/3 of the drive, idle was poor, tip in was poor with a very noticeable hesitation. Stopped for two hours and upon restart, it idled fine. Tip in was very good. I think I detected one minor hesitation. Top end performance was different, but not as noticeable.

No data for today, getting over a 24 hour stomach bug.

Bill
 

RootesRacer

Donation Time
Do you have any mapping modifications from the aux input?

The input in your case would float (meaning that it goes where stray electrostatic charges take it).

If you have any timing changes or fuel changes from the aux input, you could remove them or terminate the aux input to a low impedance source.


BTW
The aux input is often used as an AFR tweak (connected to a potentiometer) or as a fuel "quality/octane" tweak.
The turbo folks sometimes use the aux input as an turbo anti-lag trigger where the timing is retarded and fuel added to improve light load turbo spool.
Aux input can also be used to set multiple rev limiters and a two-step trigger.
 

Bill Blue

Platinum Level Sponsor
Yes, I had the aux input wired so that when the starter was engaged, the Aux Input received 2.16 volts and spark was retarded 16 degrees. I noticed the engine was running retarded and there was over 2 volts on the Aux Input. So I disabled that function. But the high voltage remained. Are you saying that when the aux input is receiving no voltage, it should be grounded?

I do not understand "terminate the aux input to a low impedance source" or how to implement it.

No comment on the varying idle and throttle response?

Bill
 

RootesRacer

Donation Time
Along with being able to alter timing off that voltage, it can also ad a fuel multiplier.

You need to make sure that the signal isnt floating, if it is and the voltage moves into a cell with a none unity (1.00) multiplier, it will modify your pulse width.

I would not use the aux input from the starter switch, for one that voltage can go to 60+ volts when the starter is released.


You REALLY need to update to the new firmware Bill.
For one, there is a new feature to run a specific timing and fuel multiplier during cranking, with additional after-start enrichment parameters.
 

Bill Blue

Platinum Level Sponsor
What signal? The Aux Input circuit now terminates in air. No electrical connection whatsoever. The ignition retard was not powered by the starter circuit, only triggered by the starter through a relay.

Will the new software package make it run the same way, all day, day after day?

Bill
 

Ken Ellis

Donation Time
Bill, without benefit of the manual in front of me, I think he's saying that it needs to be either connected and used, or connected to something fixed/static in the event it's not needed. A floating electronic input is undefined in state, and can present inconsistent input to the circuit based on whatever electrical environment the input is subjected to. So, static charges, induced voltages from nearby conductors, and possibly even signals generated by the computer controller itself could be picked up and arbitrarily interpreted and acted upon by the unit. Hence the need to either use it for something, or "tie it down". Now, without the manual, I can't guess whether it should be grounded, connected to +12, or to some lesser voltage, or connected to something it interprets as a signal, like tach or whatever. But it looks like 'connected to air' is not good. If your particular setup has a weighting factor associated with that input, then any induced signal it registers could be presenting a much-magnified set of data to the computer.

(By the way, this need for inputs to be non-floating is common in electronics.)

So, it sounds like that connection is a candidate for what is causing unpredictable, variable results. He said not to connect it to the starter, due to potential voltage spikes, but again, I can't say to connect it to the battery (or whatever) without the manual.

But it does look like you're on to something.
And when he gets back to you, I'm sure he can recommend a specific connection point to you.

And, it looks like moving to the new firmware now will allow you to 'not mess with it' once you get this aux matter settled.

Hang in there!
 

RootesRacer

Donation Time
What signal? The Aux Input circuit now terminates in air. No electrical connection whatsoever. The ignition retard was not powered by the starter circuit, only triggered by the starter through a relay.

Will the new software package make it run the same way, all day, day after day?

Bill



You are going to have to explain your connection from the relay to the aux input.

Basically the aux input has a rather high input impedance and doesnt have a resistor to pull a floating signal (no connection to the outside world) to ground.
This makes that signal neander if left disconnected (floating).

This isnt a problem if the aux fuel multiplier table is all 1s, and the aux ignition table is set to all zero (no advance or retard).


The new firmware will allow you to install a fixed cranking timing figure without connection to the aux input or its tables.
For instance you tell the ECU that cranking is below 300RPM and while cranking to deliver 2 degrees advance (ignores the ignition map) and perhaps 20% more fuel. Once the engine starts, it uses the normal ignition map and the fuel enrichment tapers down to the normal mapping values.
 

Bill Blue

Platinum Level Sponsor
Currently the timing "issue" is really not an issue with me. I can live with a little starter kick back. However, I cannot live with a situation in which the car suddenly needs a major retune in order to run in a drivable manner, only to find a few days later it has to be retuned to the previous tune. If this basic problem is solved, I'm willing to get the update. If it is not, I view the update as a waste of good time that could be devoted to a different system.

As to the Aux Input parameters: All fuel enrichment parameters are 1.000. All spark parameters are .000 degrees.

Bill
 

RootesRacer

Donation Time
If it is not, I view the update as a waste of good time that could be devoted to a different system.

Bill


Bill,

Considering all the time I have spent with you keyboard and phone, I consider this a moderate insult to say the least.

If the ECU calculates the same pulse width day to day and the fuel delivered changes by the phase of the moon, best to look at the moon.

I suspect you are going to have similar problems no matter what system you use becuase the ECU simply is not the problem.
 

Bill Blue

Platinum Level Sponsor
Okay, the problem is not with the ECU.

I have rerouted and redone body and computer wiring. Changed injectors. Changed FPR multiple times. Made a new fuel rail. Put in a larger fuel return line. Replaced the fuel pump and fuel filters. Redone the sensor hookups to the intake. Placed restrictions in the sensor hoses. Made a new intake manifold and tested it in two configurations. Changed AFR sensors multiple times. Changed the TPS multiple times. Changed the air delivery system.

Sorry if your insulted and I appreciate the time, but for every hour you have spent talking to me, I've spent weeks working on this thing and the problem I experienced the first week I attempted to tune remains.

I was hoping someone would have some ideas. I honestly don't know what else to do.

Bill
(edit) we can eliminate the moon. The changes occur much too quickly.
 

RootesRacer

Donation Time
Send me your map file, I'll go over it with a fine toothed comb.

If you can generate two different log files with the two different conditions, this would be helpful too.
 

Bill Blue

Platinum Level Sponsor
Send me your map file, I'll go over it with a fine toothed comb.

If you can generate two different log files with the two different conditions, this would be helpful too.

This might take a while. I have loads of files, but they all probably have different tunes. I'm still under the weather and don't feel like doing any heavy duty thinking, which for me, is required when fooling with a computer.

Bill
 

todd reid

Gold Level Sponsor
Wtf

Forgive me for chiming in - you guys are both light years ahead of me on this subject, but something Bill said earlier in the thread struck me.

Bill has had basically the same problem (unpredictable performance) with two different engines (Pinto & Duratec) and two different fuel delivery systems (carb & EFI). So let's identify what these two setups have in common, and look for a problem there.

Bill will have to answer that question, but I am thinking fuel tank, possibly fuel filter, fuel lines, fuel pump. Could we have some debris in the fuel system randomly influencing the results?

I hope this helps. Hang in there Bill!
 
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