Hemi jeep surging idle

[mmasedawgg]

Hey everyone,

Ive got a 2007 wrangler with a 2014 truck 5.7 eagle motor. It has a texas speed 220/230, short headers, obviously no mds and a cold air intake. it has valve springs and pushrods with a cam lock too. When this thing is idling it surges a little and will intermittently pop out the exhaust. I thought it was the base spark and torque reduction spark tabledifferences because it would randomly retard spark from 15deg to -11deg and pop, so i matched the torque reduction and base spark maps and it nearly stopped doing it when i matched the two tables. I have been chasing this issue for a few weeks and have finally gotten it to idle semi well. I know the HO2S heater code is concerning but it is working fine, i have tested it with multimeter and ir thermometer. It is just the pcm. I had ordered a new pcm and the codes went away but it bricked on me when tuning it so i had to put the old one back in for now. The jeep runs pretty good other than the loud popping at low rpm load, and idle. I know the ve tables still need a little bit of work but im really lost with the idle situation and i need some help getting it dialed in. if anyone is willing to point me in the right direction or help me out that would be awesome. my options are limited because i live in fairbanks alaska where there are no in state tuners. Thanks in advance guys
cam: 220/230
lobe lift .353 int and exh
lobe lift at 1.65 .582 int and exh
lobe sep 110
ICL 108
attached is the current cal and a log

idle and drive 1.hplJK Hemi tune Idle, idle and drive.hpt

[rockystock]

Post another run file, but also log the "idle desired RPM" and "aircharge"

[rockystock]

You need to drop your minimum spark table down - current settings aren't allowing the spark timing to decrease it looks like you're getting a lot of knock retard as a result. I'd recommend making the entire "minimum spark" table no more than about 7 degrees for your cam.

Did you try the settings I posted a few weeks ago? https://forum.hptuners.com/showthrea...484#post707484

[mmasedawgg]

rockystock,
I tried both calibrations you posted on my last thread. No dice. I also tried reducing my base timing table and it just popped constantly, still idled though. I don't understand where you're seeing the KR because it is not showing in the channels on the log. I pasted the VE tables from the 2014 truck tune you posted on my last thread, and raised the base spark back up to 18 deg on idle and it has almost stopped popping, only happens sometimes now, mostly when coming off the throttle or when letting the clutch out. Its also still surging, i think it needs some better throttle control, but don't know what tables to touch.
Current cal and a log attached.
JK hemi, truck VE, 18 deg idle.hpt
truck ve 18 deg idle.hpl

[white1]

JK Hemi tune give a shot.hpt

See how this does

[white1]

Also, did you swap reluctor wheel?
Cant remember what year they changed the first time

[mmasedawgg]

No haven?t touched reluctor wheel. Why would that need to be changed? Ran fine before cam swap

[rockystock]

JK Hemi tune give a shot.hpt

See how this does

Spark Proportional P/N = OUCH haha.

[rockystock]

rockystock,
I tried both calibrations you posted on my last thread. No dice. I also tried reducing my base timing table and it just popped constantly, still idled though. I don't understand where you're seeing the KR because it is not showing in the channels on the log. I pasted the VE tables from the 2014 truck tune you posted on my last thread, and raised the base spark back up to 18 deg on idle and it has almost stopped popping, only happens sometimes now, mostly when coming off the throttle or when letting the clutch out. Its also still surging, i think it needs some better throttle control, but don't know what tables to touch.
Current cal and a log attached.
JK hemi, truck VE, 18 deg idle.hpt
truck ve 18 deg idle.hpl

Not sure what's going on with your friction base table, but it's setup backwards from most calibrations - your low RPM areas should be lowest in friction torque... I'd recommend taking a stock 5.7 table and multiply the whole table by 0.5 if you're having trouble with hanging RPM. This table will also affect your idle so you want to sort it out sooner rather than later.

Now with the Aircharge being logged, you can set up a graph of knock retard vs. RPM vs. Aircharge - use the RPM and Aircharge axis values in your base spark table. Here's what it looks like with my scanner settings to give you an idea:

mmasedawgg KR - spark graph.jpg

Moving to the surging idle - it looks like most of your surging is happening as the RPM climbs above about 1000 RPM. At that point, your spark advance is falling off the 18-degree plateau in the minimum spark table, spark advance falls, RPM drops, spark goes back up to 18, and round you go.

You can now make a math and plot your RPM error:

mmasedawgg RPM Error Chart.jpg

You'll see that the error is spending a bit more time above the Idle Desired RPM, so as a first adjustment I'd recommend multiplying your Throttle Integral P/N values, from -100 to -1, by 1.2. That will add some negative torque when the surge is above the desired RPM. The idea is to try to get the surge to be centered over the desired RPM. After it looks centered, you can try adjusting the throttle derivative P/N table. Notice that this change is not adding much torque - you only want to make small changes, usually to one table at a time to avoid complete confusion.

mmasedawgg Idle Throttle Integral.jpg

You still have a trouble code for your O2 sensor, B1S1 that's keeping you in open loop "fault." When the engine is in open loop, the WOT spark tables are used so you'll want to look into that too. The open loop running might also be contributing to the popping exhaust sounds...

[white1]

Spark Proportional P/N = OUCH haha.

all my customers like the chop lol

[mmasedawgg]

Rockystock, just seeing your reply. Thanks so much for taking your time to explain and provide screenshots. I haven?t been able to get back to the jeep this week because it?s 45 below zero and the starter won?t even try to crank. Going to revisit the issue when it warms up some, hopefully first week of January. Thanks again for helping me out.

[MI_Tuning]

try this out. should tame your surging

[mmasedawgg]

Heres the log from MI-Tuning calibration. Idles good now no more surging but it pops constantly. I think its because the spark tables.
try this log.hpl

[MI_Tuning]

try this , if it still pops you have something else going on.

[mmasedawgg]

Sorry for not getting back to you right away MI_Tuning, Rockystock, white1.
I appreciate all of your help so much. The original calibration MI tuning wrote is idling very well. It?s just backfiring out the exhaust like hell. This weekend, I thought I was in sheer denial and so I took the front cover, oil pan and pump off so I could 100 percent verify that the timing was on. It was. I was kind of hoping it was off a tooth just for the sake of a simple mistake. I put it back together, tightened everything by hand and used a torque wrench. Then I took the intake off, thinking I may have a vaccum leak. Everything looked fine, all the seals were seated properly. Put that back on, made sure it was sealed up good. Hooked up a vacuum gauge and started it, still got the popping issue right away. It idles at 11 inches of vacuum, steady. No idle surging. I hooked up and started logging to see if I could get a misfire to come up on the log or something of the sort. No misfire on the misfire counters. History or current. Then I figured maybe I have a stuck open injector, so I took the rails off, supplied regulated shop air at 50 psi and pulsed all the injectors with my power probe. None of them leaked air or fuel. All the spray patterns looked normal to each other. It runs pretty decent all except the idling backfire. I was just turning cookies in the driveway giving her the beans. And it does great. Just need to figure out the stupid popping issue. Any suggestions?

[rockystock]

I think the popping is caused by the spark timing dipping below a level the cam can handle. Spark too low will allow too much unburned fuel to pass into the exhaust, and occasionally the fuel will ignite downstream, causing the bangs. I'd recommend raising the spark minimum table - set all values less than 10 degrees to 10. Also, the table (Torque Model -> Inv. Efficiency) - I'm still trying to figure it out, but it seems to act as a gain control for all spark-related torque adjustments. Dialing it down will allow the spark timing to generally be closer to the main spark tables. It will also reduce the amount of idle spark adjustments and effectively raise idle spark timing, resulting in less chop and less of a raw gas smell from the exhaust.

The trick is to get your spark timing higher at idle, and maybe reduce the amount of spark-sourced idle control, use the throttle idle settings to keep things steady.

Try logging your fuel flow and see if you can minimize it at idle. My setup has been as low as ~3.7-3.8 lb/hr at hot idle.

[rays04gtx]

I changed your Cold air source from MAT to IAT , and modded some of the Timing tables also added .0XXX( I don't remember ) to your Airflow table....It's all in the Tune calibrations tab.

your Current Ambient Temp is PHUCKING COLD .....I'm glad I'm in PA this time of year.

Rocky is on the right track, it's just that I think you it's too much ATDC cam timing, we have to remember + Numbers in our tables are actually - Numbers in the real world (BTDC), and - Numbers in these tables are ATDC

Another thing you might want to look at is Start up Airflow, also let's get so Desired FA logging, the cold start FA table up table can last as long as 6 1/2 Mins after start up.

[rockystock]

I changed your Cold air source from MAT to IAT , and modded some of the Timing tables also added .0XXX( I don't remember ) to your Airflow table....It's all in the Tune calibrations tab.

your Current Ambient Temp is PHUCKING COLD .....I'm glad I'm in PA this time of year.

Rocky is on the right track, it's just that I think you it's too much ATDC cam timing, we have to remember + Numbers in our tables are actually - Numbers in the real world (BTDC), and - Numbers in these tables are ATDC

Another thing you might want to look at is Start up Airflow, also let's get so Desired FA logging, the cold start FA table up table can last as long as 6 1/2 Mins after start up.

Good Stuff. In addition to the FA Cold Enrich adding warm-up fuel, the Burn Fraction Inverse also adds fuel while in warm-up.

[rays04gtx]

Good Stuff. In addition to the FA Cold Enrich adding warm-up fuel, the Burn Fraction Inverse also adds fuel while in warm-up.

Dam it I wish this place had a Like Button......WTF

I thought about Burn Fraction half way through another thread I was replying to.......LOL

[PurpleRam]

How are you making out? I know it’s cold up there, so I doubt you have had time to work on this.