Power Enrichment Delay

[shogunnamedmarcus]

I cannot eliminated the delay in power enrichment. Under the power enrichment tab - throttle and delay settings, I have done the following:
-Zeroed the WOT delay time
-Increased the VSS to 128 mph so the WOT delay should be inactive
-Zeroed the TPS Delta Max
-Reduced the RPM delay to zero again disabling the delay above that rpm.

I have also reduced the WOT Pedal Threshold from 3.78V to 3.0V in an effort to have PE start earlier with no affect. The vehicle remains in Closed Loop commanding an AFR of Stoich despite reading 100% load and a MAP reading of 90-100kPa.
This delay can be anywhere from 10-20 seconds, and will occur whether going WOT from a stop or going WOT or increasing to large TPS values at speed.

Am I missing something here? The vehicle is a 2005 Jeep Wrangler 4.0L. Any suggestions are greatly appreciated!

[06300CSRT8]

sensed map disabled or enabled? post up your tune.

[shogunnamedmarcus]

Sensed MAP is enabled.

[Homer]

The first few rows of you PE table are 0 so it's not going to command anything but stoich. However, if you are hitting Pr of 0.8 and above it should be commanding PE.

I thought I read in an old post that sensed map disable works better for older years? You certain sensed MAP is reporting correct pressure or are you reading from MAP (SAE)?

[shogunnamedmarcus]

The first few rows of you PE table are 0 so it's not going to command anything but stoich. However, if you are hitting Pr of 0.8 and above it should be commanding PE.

I thought I read in an old post that sensed map disable works better for older years? You certain sensed MAP is reporting correct pressure or are you reading from MAP (SAE)?

I've read the pressure on both HP tuners using the vehicle support channel not generic SAE as well as separate scan tool and they report the same so I assume the MAP is correct. I realize I haven't added to the PE table below 80 on this tune, I've been trying to fix this delay at the stock PE levels before moving on to anything else. Stock only starts PE above 92kPA, so I extended it down to 80 in an effort to see an improve this, but it didn't help. I can fill in below 80 and rerun, but it just struck me as odd that the parameters appear to be met and it will just hang at 90-100kPa and not switch to OL.

I thought sensed MAP was the actual reading not a calc'd one? I assumed that would be the more accurate, but I can try disabling sensed MAP if you think it may help.

[06300CSRT8]

try disabling sensed map.

[06300CSRT8]

and fill in the top of your PE ratio table to match the rest. Either or both of those should fix the issue.

[shogunnamedmarcus]

and fill in the top of your PE ratio table to match the rest. Either or both of those should fix the issue.

Made the changes. Weather hasn't cooperated for a lengthy log, but filling in the lower portions of the PE table seems to have helped the lag/transition. As a side note it instantly hated disabling sensed map and had loping idle issues.

One related question came up - as an experiment to bring PE in earlier I also tried lowering the WOT pedal threshold voltage even further to 2.5v. The jeep has heavy 35" tires and inadequate gearing so the load tends to be fairly high at lower rpms not just traditional WOT. The factory service manual say 2.608v above learned idle voltage is deemed WOT. So if idle is .62v +2.608v = 3.228v is WOT. So my specific question is; is this 2.608v above idle a hard parameter and does setting the WOT pedal threshold lower than 3.2 have a pronounced affect? At first pass, ( although brief), lowering the voltage did not seem to correspond with earlier WOT than the previous setting of 3.0v. Anyone experience this or have any insight?

[Homer]

How low have you gone on WOT pedal threshold voltage? You don't have a VVT motor so you should be able to run the WOT pedal threshold low...1.6V to 2.5V.

[shogunnamedmarcus]

How low have you gone on WOT pedal threshold voltage? You don't have a VVT motor so you should be able to run the WOT pedal threshold low...1.6V to 2.5V.

I currently set it at 2.5v as a test. I should be able to get more time on this setting it today, but the brief test showed that @ 2.5v that puts me about 60-65% TPS. Bringing up the TPS progressively to that range and slightly above, while under high load still had the O2s active and the fuel system in CL. I'll log more time and even lower the threshold as a test.

[shogunnamedmarcus]

Back again after some runs. PE still isn't behaving better or predictably. I lower the WOT voltage down to as far as 1.5v, filled in the lower portions of the PE table, and also maxed the PE increase rate and there is still a delay. These changes were made progressively and each step along the way didn't remedy the problem. Attached are the tune and a log illustrating the current tune and resulting delay condition. Any other ideas? This one is driving me crazy!

[06300CSRT8]

So just a hunch here, but youre actually never tripping true open loop, if you look at the modeled exhaust temp, you are actually tripping your exhaust protection limit of 1652F. I bet if you upped that limit in the Fuel->Temperature control, you would actually NEVER go into open loop.

So back to the original problem, your TPS% look really low, can you add to the log ALL of the various PIDs for pedal and throttle, including the voltage (not just the ratio like you have). You are also missing the ETC threshold setting in your tune file, which is usually in the Torque Management area. There are two WOT thresholds, one for the actual throttle body (ETC) and one for the pedal. The pedal one will only control timing and torque management, ETC / throttle body one would control fueling.

[06300CSRT8]

also do you have a copy of the stock tune?

[shogunnamedmarcus]

Here is a copy of the stock tune. I haven't changed much because this issue PE issue is plaguing me and preventing me from moving on to much else. I'll add the PIDs with a log this evening, but the architecture of PCM for this old Jeep is severely limited and there isn't may options for vehicle specific PIDs compared to a GM or even a later model Jeep.

The TPS is lower in this log but the pedal was not to the floor. It was substantially over the 1.5v threshold though so according to the parameters in the PE table it should have considered this WOT - no?

I don't see another WOT threshold table in the stock tune with the exception of under Airflow Tab- Electric Throttle -Throttle Body Model. I don't know the relation or the maths behind this table.

Thanks for you help!

[06300CSRT8]

The only thing in your log is your throttle body position, not your pedal position. You were near 58% most of the run, which implies a 1.9 volt throttle body position (most DCX throttle bodies are fully open at 3.8 volts). Even though you cannot see the TPS WOT threshold setting in your tune, 99% of the time its set at 3.2 volts or so, this is why open loop isn't kicking in.

I know you don't have the tables, but here is how it all works. There is a pedal vs power table that controls the relationship of the throttle body position versus where your foot is. You can have the throttle body be fully open at just half pedal if you wanted to, and this is why fueling follows the throttle body and NOT your pedal. What matters most is how much air is being let into the engine, not where your foot is.

We need a way to figure out the voltage of both the throttle body and your pedal, hopefully the scanner has them.

Either way you should be asking support to add ECM 13530 - ETC Pedal WOT to your tune. You only have ECM 44442 currently.

[shogunnamedmarcus]

Attached is another log with all the available PIDs for throttle and pedal. As you can see despite being a vehicle specific channel, the accelerator pedal position and power do not report at all. The second short log is just to illustrate the full swing of both TPS and throttle voltage KOEO.

One question I have is because the throttle body is cable driven, wouldn't the only voltage reported come from the feedback of the TPS sensor and these PIDs would be a product of that? Out of curiousity I previously back probed the TPS sensor connector and found voltage closed position to be .62v, 2.1v@ approx. 50% and 3.78v at WOT. This doesn't match the voltage reported through VCM Scanner, but I chalked it up to the PCM learning the closed voltage and then using the remainder as the operating range.

[shogunnamedmarcus]

Posting a conclusion here. The failure to enter PE was due to a defective tps. At idle and when snapping to WOT the TPS voltage was both within spec according to the FSM and smooth , however when holding position the signal voltage would reach a peak and then slowly bleed off and lower. With a new TPS and stable signal voltage it's now following the tune. Thanks for the advice everyone.

[06300CSRT8]

awesome news, something def seemed off in your logs, i just assume maybe you were lifting off the throttle without seeing your pedal %.

[raceghost]

How does the PRatio PE table work? High numbers better, or lower numbers better?

[Homer]

How does the PRatio PE table work? High numbers better, or lower numbers better?

Explained here
https://forum.hptuners.com/showthrea...el+mass+tuning