Misfire under heavy boost
#1
New Member
Thread Starter
Misfire under heavy boost
09 turbo, 63K on LDK after porus LNF, 183K on stock injectors, Car is tuned 25psi, daily driver 150 mile round trip each day. My problem started little over a week ago and would miss with a flashing ses light under hard boost, if I did this several times I would get a solid ses (P0303), changed plugs NGK LTR61X-11 and swapped 1 & 3 coils, no luck car would continue to miss sometimes on deceleration and around 40 mph to the point I wasn't sure if it was going to straighten out. Finally emailed an ecotec authority and they said after they asked what plugs I put in:
That is likely your issue. Stock plugs are ACDelco 41-108s. DI cars are EXTREMELY picky on the plugs, and you need to ONLY run the stock ones. I believe if you put the factory ACDelcos back in your misfires will go away.
I really felt like I was throwing money away to swap to new plugs after the other ones only had 400 miles on them and sure enough I did. Installed new plugs last night and today, misfire with P0300 and P0303. I'm thinking injector but would like some input, thanks.
That is likely your issue. Stock plugs are ACDelco 41-108s. DI cars are EXTREMELY picky on the plugs, and you need to ONLY run the stock ones. I believe if you put the factory ACDelcos back in your misfires will go away.
I really felt like I was throwing money away to swap to new plugs after the other ones only had 400 miles on them and sure enough I did. Installed new plugs last night and today, misfire with P0300 and P0303. I'm thinking injector but would like some input, thanks.
#4
Senior Member
iTrader: (1)
Are you able to log? It seems like something is not allowing enough fuel into cylinder 3 (you ruled out spark) so injector seems likely to me as well. You could trying cleaning before replacing, but that is quite a bit of work to get there. I'd just hate to pay for an injector if it's not the cause. It could be due for a valve cleaning as well, but that seems like idle symptoms would come up more than high load for valve coking issues. I do know my VW picked up a lot after valve cleaning, both at low and high load. There could also be a VVT issue but I'd expect a different code to come up like CKP/CMP sensor mismatch.
#14
New Member
Thread Starter
Misfire is gone, walnut blasted valves and replaced injectors with cleaned and tested ones done by Injector Rx out of Houston Tx
.
Dates are wrong on these pictures. 63K miles on LDK
The set up, had to modify some to get wand to fit hose, easy job, was worried about having enough media, could do 4 more cars with what's left
Before and after cleaning, injectors had 186K on them
.
Dates are wrong on these pictures. 63K miles on LDK
The set up, had to modify some to get wand to fit hose, easy job, was worried about having enough media, could do 4 more cars with what's left
Before and after cleaning, injectors had 186K on them
#15
Senior Member
Old thread - but I'm glad you resolved the issue! Any updates on this (has it come back or was it resolved for good, etc)?
I have a 09 SS (Which is why I'm even on this forum) but I also have a 2017 Ford Fusion with the 2.7L EcoBoost GTDI. It runs into something similar where it'd misfire under heavy boost but not enough to set off a DTC. If I pull the Mode 6 data, I'll almost always see the largest number of misfires with cylinder 6. Say I do a 30 minute drive, as long as I stay out of boost I may see a max of 5-10 misfires since key on. If I go WOT for a few seconds, I might see 60-150 misfires almost all of them from cylinder 6 while under boost. The datalog shows this start to happen when the ECU closes the throttle for upshifting or whenever.
If I go WOT with the ECT about 170F-180F and the ambient temp is cool, it may misfire so badly that the engine light will flash and I can't accelerate past 55 mph no matter how hard I try. The automatic transmission doesn't seem to work in this failsafe mode either as I am clicking through the gears without any impact. I've had this misfire condition only 3-4 times, once it stalled coming to a light, and another it actually set a pending DTC.
Engine did this with a tune as early as 8k-10k miles and now has just under 20k miles. I played the game of change spark plugs, make sure the gap is right, swapped coil packs, etc... to no avail. It's always Cylinder 6. During long cold start idling, I may see more misfires from cylinders 3 and 4 than 6. As soon as it switches to warm idle, it goes to 6. A few other EcoBoost owners have experienced similar problems but not everyone.
I am not sure injectors and valves would be that dirty. I do know GTDI is very finnicky about these things.
I have a 09 SS (Which is why I'm even on this forum) but I also have a 2017 Ford Fusion with the 2.7L EcoBoost GTDI. It runs into something similar where it'd misfire under heavy boost but not enough to set off a DTC. If I pull the Mode 6 data, I'll almost always see the largest number of misfires with cylinder 6. Say I do a 30 minute drive, as long as I stay out of boost I may see a max of 5-10 misfires since key on. If I go WOT for a few seconds, I might see 60-150 misfires almost all of them from cylinder 6 while under boost. The datalog shows this start to happen when the ECU closes the throttle for upshifting or whenever.
If I go WOT with the ECT about 170F-180F and the ambient temp is cool, it may misfire so badly that the engine light will flash and I can't accelerate past 55 mph no matter how hard I try. The automatic transmission doesn't seem to work in this failsafe mode either as I am clicking through the gears without any impact. I've had this misfire condition only 3-4 times, once it stalled coming to a light, and another it actually set a pending DTC.
Engine did this with a tune as early as 8k-10k miles and now has just under 20k miles. I played the game of change spark plugs, make sure the gap is right, swapped coil packs, etc... to no avail. It's always Cylinder 6. During long cold start idling, I may see more misfires from cylinders 3 and 4 than 6. As soon as it switches to warm idle, it goes to 6. A few other EcoBoost owners have experienced similar problems but not everyone.
I am not sure injectors and valves would be that dirty. I do know GTDI is very finnicky about these things.
Last edited by metroplex; 09-09-2021 at 11:22 AM.
#16
Senior Member
Old thread - but I'm glad you resolved the issue! Any updates on this (has it come back or was it resolved for good, etc)?
I have a 09 SS (Which is why I'm even on this forum) but I also have a 2017 Ford Fusion with the 2.7L EcoBoost GTDI. It runs into something similar where it'd misfire under heavy boost but not enough to set off a DTC. If I pull the Mode 6 data, I'll almost always see the largest number of misfires with cylinder 6. Say I do a 30 minute drive, as long as I stay out of boost I may see a max of 5-10 misfires since key on. If I go WOT for a few seconds, I might see 60-150 misfires almost all of them from cylinder 6 while under boost. The datalog shows this start to happen when the ECU closes the throttle for upshifting or whenever.
If I go WOT with the ECT about 170F-180F and the ambient temp is cool, it may misfire so badly that the engine light will flash and I can't accelerate past 55 mph no matter how hard I try. The automatic transmission doesn't seem to work in this failsafe mode either as I am clicking through the gears without any impact. I've had this misfire condition only 3-4 times, once it stalled coming to a light, and another it actually set a pending DTC.
Engine did this with a tune as early as 8k-10k miles and now has just under 20k miles. I played the game of change spark plugs, make sure the gap is right, swapped coil packs, etc... to no avail. It's always Cylinder 6. During long cold start idling, I may see more misfires from cylinders 3 and 4 than 6. As soon as it switches to warm idle, it goes to 6. A few other EcoBoost owners have experienced similar problems but not everyone.
I am not sure injectors and valves would be that dirty. I do know GTDI is very finnicky about these things.
I have a 09 SS (Which is why I'm even on this forum) but I also have a 2017 Ford Fusion with the 2.7L EcoBoost GTDI. It runs into something similar where it'd misfire under heavy boost but not enough to set off a DTC. If I pull the Mode 6 data, I'll almost always see the largest number of misfires with cylinder 6. Say I do a 30 minute drive, as long as I stay out of boost I may see a max of 5-10 misfires since key on. If I go WOT for a few seconds, I might see 60-150 misfires almost all of them from cylinder 6 while under boost. The datalog shows this start to happen when the ECU closes the throttle for upshifting or whenever.
If I go WOT with the ECT about 170F-180F and the ambient temp is cool, it may misfire so badly that the engine light will flash and I can't accelerate past 55 mph no matter how hard I try. The automatic transmission doesn't seem to work in this failsafe mode either as I am clicking through the gears without any impact. I've had this misfire condition only 3-4 times, once it stalled coming to a light, and another it actually set a pending DTC.
Engine did this with a tune as early as 8k-10k miles and now has just under 20k miles. I played the game of change spark plugs, make sure the gap is right, swapped coil packs, etc... to no avail. It's always Cylinder 6. During long cold start idling, I may see more misfires from cylinders 3 and 4 than 6. As soon as it switches to warm idle, it goes to 6. A few other EcoBoost owners have experienced similar problems but not everyone.
I am not sure injectors and valves would be that dirty. I do know GTDI is very finnicky about these things.
#1. Did it do any of this before you had it tuned, and what mileage did you get it tuned at?
#2. What fuel was the tune set with and what are you using. Most tunes move past using anything less than 91, but there is tunes for lower octane. Depending on certain tune factors, I've read those Ecoboost 2.7/3.5 love to carbon valves up quickly.
#17
Senior Member
I don't recall having any of these problems with the stock tune. I had started tuning it fairly early on, so no real chance for the valves to gunk up. The EcoBoost PCV systems are different from LNF, and I have seen GM make a large number of changes with the LTG as well.
Ford's fueling is different from the LNF. While both EcoBoost and LNF have wideband O2s from the factory, Ford flex fuel vehicles use a virtual/inferred alcohol content in lieu of an actual alcohol sensor. From lessons learned the stock EcoBoost fueling will adapt to at least E50 without issues. That said, I've had it happen with 93 octane, E30, as well as full E85. The type of fuel doesn't seem to impact it from experimentation.
Ford's fueling is different from the LNF. While both EcoBoost and LNF have wideband O2s from the factory, Ford flex fuel vehicles use a virtual/inferred alcohol content in lieu of an actual alcohol sensor. From lessons learned the stock EcoBoost fueling will adapt to at least E50 without issues. That said, I've had it happen with 93 octane, E30, as well as full E85. The type of fuel doesn't seem to impact it from experimentation.
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