Idle surge (mostly in Park/Neutral)
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Idle surge (mostly in Park/Neutral) Trying to finish up the tuning on the car since the cam change. Everything was running well before.
Went from a 230/238 113+3 cam to a 239/247 113+3 solid roller (will behave as a 234/242 once lash is figured in)
I have done a MAF and VE correction, RAFIG, and tried messing with under/over timing...finally used bi directional controls to lock the timing in and it didn't change anything.
The wideband shows really lean at idle, but it always has. Fuel trims are negative, actually a little high negative in the -8% to -12%.
The idle is ok cold and up until it's getting up around 160* engine temp and higher getting worse up until full operating temp where it will pretty much surge constantly sometimes just flat out dying quickly.
The wideband sensor is brand new. I had to replace it due to the old sensor dying. I ran some leaded race fuel in the car. I'm starting to think it might have damaged the narrowband o2 sensors as well.
I'm under the weather and would like to get this lined out but my patience for trying to figure it out alone is pretty low. So if anyone would care to take a look at this tune and idle log and offer any insight I would be very appreciative. Some parts of it could be a mess...if so you won't hurt my feelings telling me so.
Went from a 230/238 113+3 cam to a 239/247 113+3 solid roller (will behave as a 234/242 once lash is figured in)
I have done a MAF and VE correction, RAFIG, and tried messing with under/over timing...finally used bi directional controls to lock the timing in and it didn't change anything.
The wideband shows really lean at idle, but it always has. Fuel trims are negative, actually a little high negative in the -8% to -12%.
The idle is ok cold and up until it's getting up around 160* engine temp and higher getting worse up until full operating temp where it will pretty much surge constantly sometimes just flat out dying quickly.
The wideband sensor is brand new. I had to replace it due to the old sensor dying. I ran some leaded race fuel in the car. I'm starting to think it might have damaged the narrowband o2 sensors as well.
I'm under the weather and would like to get this lined out but my patience for trying to figure it out alone is pretty low. So if anyone would care to take a look at this tune and idle log and offer any insight I would be very appreciative. Some parts of it could be a mess...if so you won't hurt my feelings telling me so.
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Just remembered I have an extra set of front O2 sensors I got from a friend. Going to toss them in and see if my LTFT change drastically.
Really starting to think the issue is being too lean at idle. It definitely makes your eyes burn
Really starting to think the issue is being too lean at idle. It definitely makes your eyes burn
Have you tried commanding a lower AFR to see if that makes it smooth out? You could command, say a 12:1 on the scanner and ignore the O2 feedback...
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That's the plan for this evening. I felt like crap last night and the smell was making me feel worse, plus it just felt like a defeat so I packed it in for the night. I'd already spent too much time trying to make the parts for my new CAI fit and was getting frustrated.
Don't look at the O2s. In fact, tune it in open loop. I never watch the wideband with a big cam for idle tuning. That's a game of chasing your tail.
With EFI Live, I would assume you can make real time adjustments to the A/F? With HPT, I can adjust the A/F in real time and see how the car reacts. I would say it probably needs to be leaner than you have it. And it may need more base timing (can't look at your tune - don't know). I know my 234/242 basically wants it so lean, I have no throttle response off idle. So then I have to enrichen about 2% or so to get some response back. But it'll just about idle without adaptive spark. And with the MAF, it'll idle at 650 RPM... with 16 degrees of overlap. Sounds like a jalopy missing.
With EFI Live, I would assume you can make real time adjustments to the A/F? With HPT, I can adjust the A/F in real time and see how the car reacts. I would say it probably needs to be leaner than you have it. And it may need more base timing (can't look at your tune - don't know). I know my 234/242 basically wants it so lean, I have no throttle response off idle. So then I have to enrichen about 2% or so to get some response back. But it'll just about idle without adaptive spark. And with the MAF, it'll idle at 650 RPM... with 16 degrees of overlap. Sounds like a jalopy missing.
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Base timing is high IMO at 25* and the over/under sometimes pops it up to 28*. I used bidirectional controls to lock it at 26* and there was no change at all.
I will try playing with the AFR both richer and leaner and see where that gets me. Thanks for the ideas.
My 239/247 solid should behave like a 234/242 once lash is factored in, but it's on a 113+3...I believe that is 12* overlap. Old cam had 8*. The cam card does say "overlap at valves" is 17* but it doesn't specify if that's hot or cold.
My target idle RPMs I've been working at are 850 and 900.
I will try playing with the AFR both richer and leaner and see where that gets me. Thanks for the ideas.
My 239/247 solid should behave like a 234/242 once lash is factored in, but it's on a 113+3...I believe that is 12* overlap. Old cam had 8*. The cam card does say "overlap at valves" is 17* but it doesn't specify if that's hot or cold.
My target idle RPMs I've been working at are 850 and 900.
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I know when I went from my 224 cam to my current 227 cam, I had to open the throttle blade and reset the TPS to get it to hold an idle, and it was very steady. My tuner was able to pretty much nail it from there. Maybe your new cam just needs the same?
If you log your IAC counts and they are relatively high, I would venture that could be the fix you need. Mine were hovering around 30
Where I'm at on mine, I had a stable idle until the lighter clutch, and now I'm surging again. Any throttle at all, and it is very stable. I can cruise at 50 mph in 6th. When I hit the clutch, it surges and never stabilizes, constantly overcorrecting.
I screwed around with all kinds of crap - and even at lunch went home and played with AFR to no avail after reading your post. Finally, I saw the IAC counts hitting 100, which tells me I need more incoming air, so I started opening up the throttle blade screw. I left it at 0.75V, and the surging was almost gone, but I'm concerned now that the TPS won't reset, and I'm still getting counts in the 50's.
You're far more knowledgable than me on these motors, but I thought I would share this much with you in case it was something you haven't tried. If you've already gone through all this, kindly disregard.
If you log your IAC counts and they are relatively high, I would venture that could be the fix you need. Mine were hovering around 30
Where I'm at on mine, I had a stable idle until the lighter clutch, and now I'm surging again. Any throttle at all, and it is very stable. I can cruise at 50 mph in 6th. When I hit the clutch, it surges and never stabilizes, constantly overcorrecting.
I screwed around with all kinds of crap - and even at lunch went home and played with AFR to no avail after reading your post. Finally, I saw the IAC counts hitting 100, which tells me I need more incoming air, so I started opening up the throttle blade screw. I left it at 0.75V, and the surging was almost gone, but I'm concerned now that the TPS won't reset, and I'm still getting counts in the 50's.
You're far more knowledgable than me on these motors, but I thought I would share this much with you in case it was something you haven't tried. If you've already gone through all this, kindly disregard.
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Yes, it would be interesting to see the IAC counts. Your VE looks a bit rough in the idle zone, maybe a little smoothing will help. I've never tuned an auto so forgive me, but the desired airflow in the upper temps looks pretty low.
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The desired airflow was higher and RAFIG had me subtract a good bit from it. No change in how the car idled after that change though.
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IAC is in the high 20s-40s, messing with it doesn't help
What does help is commanding a 15.8-16.0 afr and idle. It instantly idles perfect. I guess I just have no clue how to make it do that once it goes in closed loop.
What does help is commanding a 15.8-16.0 afr and idle. It instantly idles perfect. I guess I just have no clue how to make it do that once it goes in closed loop.
OK, I can help you with that...
1. Go to fuel>Power Enrich. Set the hot and cold PE throttle to zero from 0-1200. This will put you in open loop all the time in that RPM range. Set your PE ratio from 0-1200 at 1.00 to prevent overfueling.
2. Go to fuel>Open&Closed Loop. Open the EQ ratio table, and set everything to 1.00 from 140-230 degrees up to about 75 kpa - something safely higher than your idle. kpa. Above that, set to whatever PE number you want to use. I use 1.15 from 80 to 105 kpa.
3. Still in fuel>O&C Loop. Set STFT Openloop to disabled. I'm also assuming your LTFT are disabled as well. shouldn't make a difference, but the LTFT will add to the fueling.
4. Now, go to your VE and in the idle regions, multiply by 14.7/16.0, or 0.919. Then, blend into your surrounding cells. Alternately, if you have the custom SD OS, you can take your zero throttle row in the multiplier table and set it to 0.919 vs 1.000.
Flash it, and you should be in open loop at idle
1. Go to fuel>Power Enrich. Set the hot and cold PE throttle to zero from 0-1200. This will put you in open loop all the time in that RPM range. Set your PE ratio from 0-1200 at 1.00 to prevent overfueling.
2. Go to fuel>Open&Closed Loop. Open the EQ ratio table, and set everything to 1.00 from 140-230 degrees up to about 75 kpa - something safely higher than your idle. kpa. Above that, set to whatever PE number you want to use. I use 1.15 from 80 to 105 kpa.
3. Still in fuel>O&C Loop. Set STFT Openloop to disabled. I'm also assuming your LTFT are disabled as well. shouldn't make a difference, but the LTFT will add to the fueling.
4. Now, go to your VE and in the idle regions, multiply by 14.7/16.0, or 0.919. Then, blend into your surrounding cells. Alternately, if you have the custom SD OS, you can take your zero throttle row in the multiplier table and set it to 0.919 vs 1.000.
Flash it, and you should be in open loop at idle
Last edited by Darth_V8r; Dec 9, 2015 at 08:25 PM. Reason: added some clarification to step 1
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From: Northwest AR
Thanks, I will try that if it doesn't clear up with a little more fine tuning.
I crawled my sick *** under the car and changed the o2 sensors and 95% of the surge went away immediately. Looks like the leaded race gas ruined those.
From the point I was at they were reading 12-14% positive fuel trims, switched them and that went to -6 to -8% or so. I am getting about a 7% difference bank to bank which I need to find the culprit of (I think it's injector related).
So today's lesson for the numb nuts like me: make sure all hardware is in working order before dealing with the software...especially if you have a solid reason to suspect there is an issue.
I should have known if it killed my wideband it probably did no favors to the narrowbands.
I crawled my sick *** under the car and changed the o2 sensors and 95% of the surge went away immediately. Looks like the leaded race gas ruined those.
From the point I was at they were reading 12-14% positive fuel trims, switched them and that went to -6 to -8% or so. I am getting about a 7% difference bank to bank which I need to find the culprit of (I think it's injector related).
So today's lesson for the numb nuts like me: make sure all hardware is in working order before dealing with the software...especially if you have a solid reason to suspect there is an issue.
I should have known if it killed my wideband it probably did no favors to the narrowbands.
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Ok, looks like NBO2S response was slow, good find 
When I read IAC counts were low (20 to 40), I was going to suggest to pull VE and MAF down in the idle range.
Yeah, being sick sux, it's hard to do much, and Mrs has no sympathy...
When I read IAC counts were low (20 to 40), I was going to suggest to pull VE and MAF down in the idle range.
Yeah, being sick sux, it's hard to do much, and Mrs has no sympathy...
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Don't look at the O2s. In fact, tune it in open loop. I never watch the wideband with a big cam for idle tuning. That's a game of chasing your tail. With EFI Live, I would assume you can make real time adjustments to the A/F? With HPT, I can adjust the A/F in real time and see how the car reacts. I would say it probably needs to be leaner than you have it. And it may need more base timing (can't look at your tune - don't know). I know my 234/242 basically wants it so lean, I have no throttle response off idle. So then I have to enrichen about 2% or so to get some response back. But it'll just about idle without adaptive spark. And with the MAF, it'll idle at 650 RPM... with 16 degrees of overlap. Sounds like a jalopy missing.
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Fought with it some more and still not any better.
I had given up and I was going to just make a tune to put it in open loop at idle but I'm guessing the above instructions are for HP Tuners. In EFI Live I do not have tables called Open and Closed loop to find the adjustments for EQ Ratio.
I had given up and I was going to just make a tune to put it in open loop at idle but I'm guessing the above instructions are for HP Tuners. In EFI Live I do not have tables called Open and Closed loop to find the adjustments for EQ Ratio.
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From: So.Cal.
Idle surge (mostly in Park/Neutral) B3605 is the Open Loop EQR table
( type B3605 in uppercase in the search box and click Search )
( Engine -> Fuel -> Mixture )
( type B3605 in uppercase in the search box and click Search )
( Engine -> Fuel -> Mixture )
Last edited by joecar; Dec 12, 2015 at 04:55 AM.
Is the hunting / surging perfectly rhythmic? Like every 1.5-2 seconds per surge?
I just discovered this the other day:
There is a proportional fueling function that by design adds and cuts fuel to keep the oxygen sensors switching at idle. Remember Jakes post about surging caused by over fueling? So you've cut fuel way back, but the idle proportional fueling function keeps adding it back in.
Disable this proportional fueling. After you set your idle to open loop, your sensors will be reading 20-ish millivolts. Proportional fueling will try to hit 800 mV. In HPT, this is in the same area as where you set your switching points. If you don't, then any attempt to lean out idle will be counter productive. Near there, there is an idle proportional adder table. Stock, it is 128 all the way across. I dropped it to 26 all the way across. This way, if there is something else also trying to cause proportional fueling, it won't add much. I might try zeroing this out.
Then, set your tune up to idle at 1100 rpm and get it stable. It should be easier. Then try to work it down 50-100 at a time. Jakes advice to put the car in commanded spark and AFR is spot on. Play with both to achieve minimum idle kpa. Here's what's funny. At 750, the MAP reads higher kpa vs 950 on mine. I guess that's just where it needs to run.
I can get it stable at 750, but then after I drive, it hunts. I ended up back at 950.
I just discovered this the other day:
There is a proportional fueling function that by design adds and cuts fuel to keep the oxygen sensors switching at idle. Remember Jakes post about surging caused by over fueling? So you've cut fuel way back, but the idle proportional fueling function keeps adding it back in.
Disable this proportional fueling. After you set your idle to open loop, your sensors will be reading 20-ish millivolts. Proportional fueling will try to hit 800 mV. In HPT, this is in the same area as where you set your switching points. If you don't, then any attempt to lean out idle will be counter productive. Near there, there is an idle proportional adder table. Stock, it is 128 all the way across. I dropped it to 26 all the way across. This way, if there is something else also trying to cause proportional fueling, it won't add much. I might try zeroing this out.
Then, set your tune up to idle at 1100 rpm and get it stable. It should be easier. Then try to work it down 50-100 at a time. Jakes advice to put the car in commanded spark and AFR is spot on. Play with both to achieve minimum idle kpa. Here's what's funny. At 750, the MAP reads higher kpa vs 950 on mine. I guess that's just where it needs to run.
I can get it stable at 750, but then after I drive, it hunts. I ended up back at 950.
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I read some threads last night where guys with big trex type cams were running a lot more timing so I tried that even though I consider mine to be high already. I set my idle timing to 30* and now the car is at least drivable without it surging and trying to die in gear.
The park issue remains, now it's just adding more to the LTFT. I saw as high as 16%.
The park issue remains, now it's just adding more to the LTFT. I saw as high as 16%.