Coyote Gen3 rough idle at start then smooth

[JeffP]

I have a new Gen3 Coyote with a Lund tune. Anytime I start it (warm or cold) it idles very rough, almost stumbles, and it sounds like one side or the other of the engine isn't firing (The exhaust will be very quite on one side while the other is normal, and sometimes it'll even shift from one side to the other while its doing this). If I give it a little gas it'll stumble/hesitate a few times then it'll typically rev up and then runs smooth until the next time I start it. This entire process typically clears out within the first 20-30secs after starting the engine.

I've tried doing a little research and see some suggest the IAC valve or it could even be the coolant sensor but I'd expect that to only impact a cold engine.

Any ideas?

Oh - No codes.

[JeffP]

Digging deeper i guess these engines don't have an IAC so likely not that.

[edwardb]

My Gen 3, also with a Lund tune, has a slightly high RPM with first started and then seems to settle down plus make a somewhat different sound. It's like the cams phase once it's running for a bit. But that's just a guess. But certainly nothing like you describe. How long since you had the Lund tune? They've been great to me when I've gone back and ask questions or an adjustment after the tune was done for a while. Seems like this is something they could help with.

[Rsnake]

Mine does the same thing and Lund told me nothing they could do about it.
Something to do with the start up tables and they cannot change it. It doesn't do it all the time and doesn't matter if it's cold or hot. Would like to fix it but it runs like a scalded cat other than the start up issue or shall we say a scalded coyote

[Alan_C]

I know that this is about Lund tunes, but has anyone called and discussed with Ford Performance? I would want a second input on the subject as Lund seems to have the attitude you get what you get.
I am glad that I have a 2nd Gen Coyote and well respected tuners that can work on my car in shop.

[Rsnake]

I might try calling ford tomorrow as I never thought about going down that road.
Thank You

[michael everson]

I have experienced the same thing on a GEN 2 Actually sounds like one whole side of the engine isn't firing. I shut it off and restarted and it went away.
Mike

[JeffP]

My Gen 3, also with a Lund tune, has a slightly high RPM with first started and then seems to settle down plus make a somewhat different sound. It's like the cams phase once it's running for a bit. But that's just a guess. But certainly nothing like you describe. How long since you had the Lund tune? They've been great to me when I've gone back and ask questions or an adjustment after the tune was done for a while. Seems like this is something they could help with.

Its been a while so I'm sure i'm out of their warranty period but its been on my list to give them a call about it.

Mine does the same thing and Lund told me nothing they could do about it.
Something to do with the start up tables and they cannot change it. It doesn't do it all the time and doesn't matter if it's cold or hot. Would like to fix it but it runs like a scalded cat other than the start up issue or shall we say a scalded coyote

My neighbor is a former very high level engineer at Ford and I was talking to him yesterday about this. He said the same thing... Initial start its defaulting to standard tables and once the EGR warms up (20-30 secs) the computer is able to properly adjust and use data from the sensors instead of the tables. It would be unfortunate if the defaults can't be adjusted. I also thought the ECU was supposed to "remember" its adjustments - I'm fairly certain I have it wired to the always hot, so something I'll also check. It was certainly my intention in the design. So i'm assuming the ECU isn't having to relearn each time the power is off.

I'll try giving Ford a call too. Sounds like at least in the small sampling - I'm not alone and this may be more common than I thought.

[JeffP]

I believe this may be resolved - haven't had a chance to get out and drive it yet (raining) but starting it up in the garage it ran fine with no issues. I'm embarrassed to admit the o2 sensors were reversed. Probably all stems from doing my wiring on my kitchen table and this harness needed to have the driver side extended and not being in front of the engine LH/RH is very relative. Anyways, pulled the harness apart, extended the other one and swapped the cables hopefully is a relatively easy fix to this issue. Thanks to the guys at Lund who pointed me towards these after taking a look at a new log file.

[JohnK]

Nice. Glad to hear that it was something relatively easy and that they were able to spot that from a log file.

[JeffP]

Nice. Glad to hear that it was something relatively easy and that they were able to spot that from a log file.

Absolutely - Just got back from a test drive and its running great.

[facultyofmusic]

Whew thanks for the update Jeff! I've been worried that I'll see the same thing on my build.

[toadster]

interesting, got a first start on our Gen 3, and literally the driver side of the car doesn't seem to be firing...
Did a start this morning for about 30 seconds and the passenger side pipes were warm to the touch, but the driver side was just as cold as if it wasn't running... very perplexing!!

btw - I have a Lund tune coming, should have it monday so that may help (hopefully!)



here are the codes, not surprising because I removed the CMCV valves (of which Lund is tuning those out anyways)

IMG_7733.PNG IMG_7734.PNG

[edwardb]

Yeah, those are the codes if your CMCV valves are removed or not plumbed properly. The difference they make to how the engine runs are pretty subtle, to be honest. Tuning them out for our purposes is fine. Really doubt they would have anything to do with cylinders not firing. I'm assuming you have lockouts installed so they're fixed open? Hopefully Lund will help you out with this. You're doing a Lund tune at the go-kart stage? I expect you know their tune requires you to do extensive driving? They provide the profiles they want you to follow while running the data log. Up to and including wide open throttle hits once the tune gets close. I never started the tune processes on mine until they were complete, legal, and I could drive extensively (and legally). BTW, another first start with open headers. Don't see ear protection. That's hard on your equipment.

[Railroad]

Lund will get you a tune to get started and then data log after street ready.

[edwardb]

Lund will get you a tune to get started and then data log after street ready.

Haven't heard that before. The several times I've used Lund I was under the impression the coverage was for three months. That's great if they would work with you that way. Especially if it doesn't start or run OK from the beginning. My Gen 3 started and ran on the base Ford tune. But was undriveable once street ready. They fixed me up.

[32J]

Me three! I have about another 900 km to go on my break-in before I approach Lund for a tune on my Gen 3. Glad to hear it was anything major.

[toadster]

Yeah, those are the codes if your CMCV valves are removed or not plumbed properly. The difference they make to how the engine runs are pretty subtle, to be honest. Tuning them out for our purposes is fine. Really doubt they would have anything to do with cylinders not firing. I'm assuming you have lockouts installed so they're fixed open? Hopefully Lund will help you out with this. You're doing a Lund tune at the go-kart stage? I expect you know their tune requires you to do extensive driving? They provide the profiles they want you to follow while running the data log. Up to and including wide open throttle hits once the tune gets close. I never started the tune processes on mine until they were complete, legal, and I could drive extensively (and legally). BTW, another first start with open headers. Don't see ear protection. That's hard on your equipment.

hopefully tomorrow we will see if the car runs better after the initial tune, not worried much about the codes and yes the CMCV are locked open
I gave them all the configs of the engine and they are aligning a base tune
I cranked up the PSI on the Aeromotive FPR to around 64 just from the battery kicking in -we've noticed the pressure rises a little when the car starts so will be watching that as well

since the car was really only firing on the passenger side, it's about 1/2 volume, plus the catalytic converters seem to muffle a bit as well

Lund will get you a tune to get started and then data log after street ready.

yes, that's the plan

Haven't heard that before. The several times I've used Lund I was under the impression the coverage was for three months. That's great if they would work with you that way. Especially if it doesn't start or run OK from the beginning. My Gen 3 started and ran on the base Ford tune. But was undriveable once street ready. They fixed me up.

I get 6 months of free support - maybe they've changed their setup

FREE - 6 Months Support (Non-Recurring)
SKU: 6_months_free_support

[JohnK]

My gen2 coyote didn't run particularly well initially. I reached out to Lund and they explained that if I purchased a tune they could send me a file to upload based on previous customers' cars with similar configurations until I was able to get up and running and datalog my own engine, within a 6 month window. If I didn't get to the point that I could do a custom tune on my own engine within the 6 month window I could extend it for another 6 months for an additional fee (which is what I plan to do.). The file they sent me that is based on other customers cars was a significant improvement over the stock gen2 tune.

[toadster]

The wait begins patience counts right now!

Thank you! There is no need to reply to this current ticket right yet. This ticket will now be written up and will go into the tuning queue. If you reply it pops your ticket out of the queue order. ETA varies. Usually its the next business day unless we are on a long weekend, have high volume, or if people are out. Once we send the tune we will be emailing you to notify that it is ready and with instructions.

[toadster]

got the tune installed last night, started right up - idles better as well
driver side pipes feel cooler than the passenger side though - very odd

gas tip-in causes a stumble, and when revving the driver side has some pops - will have to log some runtime and get back to them, no CEL this time

[JeffP]

I did my logging drives yesterday, and trying to get the final WOT from 2500-7500 rpm is proving to be a challenge. I certainly feel like i've got the pedal on the floor but its not even close. I've hit the rev limiter and still haven't had the pedal past 70% getting there. trying to find a safe place to do it even just once is challenging.

[Jeff Kleiner]

got the tune installed last night, started right up - idles better as well
driver side pipes feel cooler than the passenger side though - very odd

gas tip-in causes a stumble, and when revving the driver side has some pops - will have to log some runtime and get back to them, no CEL this time

Todd,
Pick up an inexpensive infrared thermometer (about 30 bucks at HF, Lowe’s, etc). You’ll be able to read each pipe individually which is great for diagnostics. Despite what my wife says you can also point it at your forehead to see if you have a fever

Jeff

[toadster]

Todd,
Pick up an inexpensive infrared thermometer (about 30 bucks at HF, Lowe’s, etc). You’ll be able to read each pipe individually which is great for diagnostics. Despite what my wife says you can also point it at your forehead to see if you have a fever

Jeff

ah yes! I do have one of those! will test again today

so strange, I've never really heard of 'one bank' not firing properly, but what do I know, this is my first crate motor startup

[toadster]

Coyote_Firing_Order.png

just as suspected... #3 and #4 cylinders are hottest, #2 and #1 are a little lower, catalytic collector is warmer (as expected)

IMG_7801.jpg IMG_7800.jpg

#5, 6, 7, 8 are all much cooler, all about the same temps, its maybe 15F hotter than ambient temps today (83F at the time of temp taking)

IMG_7802.jpg IMG_7799.jpg

[Jeff Kleiner]

15 degrees over ambient is just the heat of compression. They aren’t firing.

Jeff

[JeffP]

Coyote_Firing_Order.png

just as suspected... #3 and #4 cylinders are hottest, #2 and #1 are a little lower, catalytic collector is warmer (as expected)

IMG_7801.jpg IMG_7800.jpg

#5, 6, 7, 8 are all much cooler, all about the same temps, its maybe 15F hotter than ambient temps today (83F at the time of temp taking)

IMG_7802.jpg IMG_7799.jpg

Did you do the wire splice on the coil over for the RPM sensor? Any chance that didn't get plugged back in or messed up?

[toadster]

15 degrees over ambient is just the heat of compression. They aren’t firing.

Jeff

yep seems apparent now - so odd!!

Did you do the wire splice on the coil over for the RPM sensor? Any chance that didn't get plugged back in or messed up?

redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow

[JeffP]

redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow

You can download LiveLink software here for free: https://derivesystems.helpjuice.com/...6005-downloads and load your csv log into it. Maybe see if anything looks odd on the STFT11 and STFT21?

I don't know the first thing about tuning, but it was pretty cool to dig into the logs a little and see whats going on.

[toadster]

yes, I do see a big imbalance on startup - but then they both zero out... hopefully they'll get back to me with some ideas


Screenshot 2023-04-27 062623.png

[toadster]

Lund replied that the O2 is really lean, but they didn't specify... I looked at the log, seems like bank 2 (which I believe is driver side) is the culprit - will have to pull the O2 wiring and check the solder joints

lean-o2-bank2.png

[Rsnake]

Mine does this crazy stuff on startup for about 10-15 seconds then it goes away. Have been told by Lund that they cannot control startup parameters and once the O2 sensor warms a little the Lund tune takes over.

[edwardb]

It's a little bit of a mystery to me that an O2 sensor issue would take out the whole bank. I can see the A-F ratio getting messed up, running poorly, MIL on with indicating codes, etc. But completely shut off? Honestly though I don't know. It wouldn't be hard to swap O2 sensors side-to-side and see if the problem moves. After you confirm the wiring is OK.

[Jeff Kleiner]

It's a little bit of a mystery to me that an O2 sensor issue would take out the whole bank. I can see the A-F ratio getting messed up, running poorly, MIL on with indicating codes, etc. But completely shut off? Honestly though I don't know. It wouldn't be hard to swap O2 sensors side-to-side and see if the problem moves. After you confirm the wiring is OK.

I think we’re seeing a “which came first, the chicken or the egg” scenario here. The sensor isn’t shutting down the bank of cylinders but rather the bank of dead cylinders is causing the sensor to be out of range. As for why one side of the engine is dead??? I don’t have a guess at this time.

Jeff

[toadster]

swapped O2 sensors side to side, still cold on driver side, and hot on passenger...

going to trace the wires that we extended to ensure we have signal... other than that i'm a bit stumped!
I wouldn't think a bad o2 signal would stop one side from firing...

[JohnK]

I think checking the solder connections is the right place to look. Whenever I'm having issues I always look at where I may have introduced failure points through human error. Hopefully it's something simple.

[JeffP]

yep seems apparent now - so odd!!



redid the purple wire splice on #4 last night, we used a wire tap previously, need to reset the tachometer setting to .5 to get readings but the Lund tuning software sees RPMs no issue

I sent a log into Lund to see if they can see anything else
only thing I can think of is maybe a bad solder joint while extending the O2 sensor wires - not the O2 bung wires, but the extensions to reach over to the driver side...
will see what they say tomorrow

Tapped purple wire - The purple wire from the harness into the non-purple wire on the coil over plug correct? I think the purple wire on the coil over is the common across all of them and each unique coil over has a different color signal wire. If you tapped purple to purple that may be messing up that side. You said you had to reset the gauge but didn't mention if it was working... Lund seeing RPM's in the log has nothing to do with this tap.

[toadster]

Tapped purple wire - The purple wire from the harness into the non-purple wire on the coil over plug correct? I think the purple wire on the coil over is the common across all of them and each unique coil over has a different color signal wire. If you tapped purple to purple that may be messing up that side. You said you had to reset the gauge but didn't mention if it was working... Lund seeing RPM's in the log has nothing to do with this tap.

correct purple to non-purple, initially we used a posi-tap and thought we maybe weren't getting a good connect - cylinder #4 is really tight against the footbox so we soldered purple to the non-purple as prescribed

as for the tach reset, I may have not saved the setting properly, assuming the memory for the tach survives battery disconnects - if not, then yes, I'll have to reset each time I would disconnect the battery I assume

[edwardb]

as for the tach reset, I may have not saved the setting properly, assuming the memory for the tach survives battery disconnects - if not, then yes, I'll have to reset each time I would disconnect the battery I assume

Speedhut gauge calibration settings don't get erased when the battery is disconnected. They're in non-volatile memory. Normally once and done.

[toadster]

Speedhut gauge calibration settings don't get erased when the battery is disconnected. They're in non-volatile memory. Normally once and done.

good to know, still need to troubleshoot the gauge, I did confirm it's set for the .5PPR when I push the menu button - still not showing revs when the car starts

sent in another log to LUND, assuming they'll just say it's O2 lean again

called Ford Performance, they suggested checking C146 pin #1 - and we're getting 12V which powers the injector/spark rails

they also suggested checking ground and should get .1Ohm or less

we're getting .1-.5 ohms between the engine ground on the passenger engine mount and a spot on the frame
also between the battery and where it's grounded it's showing .3-.5 ohms which seems off as well

pulled a plug from bank #2 (actually plug #6) after the logging, definitely not firing

IMG_7809.jpg