Surging - Bad fuel injector?

S

SHO9987

New member
Been experiencing a surging at light throttle/low rpm situations.  I can feel the car surging and see the fluctuation in RPMs.  If I give it anything more than 30% throttle the car behaves normally.  94K miles on the car, see mod list below.  No CELs or any lights for that matter.  Thought it was the torque converter going out on me; took it to the transmission shop for a diagnosis, all he could find were several misfires on cylinder #1 and #6... obviously not enough to flip the light.  He reported that the transmission was working well, fluid was clean, and he did not think there was an issue with the torque converter. 

I now turned my attention towards these misfires.  I've got new plugs and MSD coils on the way.  I'm considering it might be a fuel injector too, usually I use some Lucas fuel system cleaner every oil change.  I added an extra dose today with a fill up to see if it helps any.  The car definitely felt a lot stronger once I had the fuel system treatment circulating.  Never have had a problem with winter gas around here either. 

Open to any other ideas or suggestions.  I did manage to get a datalog of the surging, but I'm not an expert at interpreting the logs.  Attached is the datalog, the surging occurs towards the end of the log in 5th gear.  There appeared to be a little knock around the same time I felt the surging.  I noted the "misfires" at the beginning of the log, I certainly didn't feel anything then, I was simply pulling out of the parking lot then. 
 
ZSHO said:
It could be a leaky injector! Do you smell any gas!

Have a Ford Mode 6 Data or Compression test performed!
In any event Check and inspect the Spark plugs for any fouling.
Check for any signs of oil inside the spark plug wells..
Coil on plugs are a likely culprit. Z

https://www.motor.com/magazine-summary/obd-ii-mode-6-diagnosis-driveability-corner-june-2002/

https://www.obd-codes.com/p0300
Click to expand...

Thanks for the info!  I haven't noticed any fuel smell, hopefully it is a bad coil.  We'll see what the new plugs and coils do when I get them in.  It seems weird that it is only low RPM though, the car performs and pulls great when I romp on it!  If it's a fuel injector though... I wonder if the methanol is making up for it? 
 
I had this same issue with my 2018. The dealer acts like I am nuts. The dealer says they cant find anything wrong with the car. I can watch the RPM gauge wiggle, I can feel the stumble when I put my hand on the intake manifold. I did upgrade to SP-542's and the problem is gone now. I am not sure if that had anything to do with it but so far, so good.
 
I had some surging issues related to a bad Throttle body, (Idle air control and other weirdness), may be worth a look if you are spraying meth or have an older model.
 
Thanks for the input everyone.  The more I drive the car and monitor everything on my livewire, the more I think it is a boost control or throttle issue, or both.  When I give it 25% throttle and the car doesn't downshift I'll see the RPM jump up and then bog back down like the throttle is closing for a second, the RPM then rises normally after that.  As for the surging when the car downshifts with minimal throttle input (when non aggressively passing someone), it feels like it is a boost issue; almost as if the turbos are creating more boost than what the car thinks I am demanding and subsequently opens the blow-off valves (which shouldn't be opening under throttle right?).  Currently I have the BOVs recirculating in stock configuration so I cannot hear if they are opening early or not, I did notice some oil/residue on my front blow off valve that I haven't noticed before.  I plan on pulling and inspecting that BOV this week when I change the plugs and coils.  Is there any way of testing the BOVs to see if they are bad?  I'll probably switch them back to VTA this week as well.  As for the throttle body, how would one go about diagnosing that? 

 
Definitely check the BOVs, particularly the orange gaskets.  A failure of the BOV is usually the gasket tearing.
 
I would temporarily Disconnect the Rear BOV Plug and only leave the Front BOV VTA! Bit of Trial and error .Z
 
New plugs and coils installed.  I don't think the plugs looked too bad, they were a bit out of gap .035 on all 6, but no oil on them.  Cleaned out the CAC as well, a little water/oil mixture, but not a whole lot in there.  BOVs looked good too, besides a small amount of oil around the o-ring of the rear BOV. 

Brad made a few adjustments to the tune as well.  In his words: it's possible that due to the turbo wheels making more airflow it could be raising the TIP pressure and the throttle is cutting back to limit power and airflow.  The initial impressions of the new tune seem promising, the surging is definitely improving with the adjustments that were made.  The daily drive-ability is a lot better too, these upgraded wheels seem to make a lot of boost and they do so quickly.  Before this tune, trying to accelerate non-aggressively was a bit difficult; too light on the throttle would result in hardly any power, a little more throttle and all of a sudden you're handed all this boost!  I still need to officially datalog it and report back to Brad when the weather is a little better here. 

Regardless, I am happy that it is just some fine tuning that needs to be done and not a bad fuel injector, I'm also happy that I've got Brad taking time to experiment and make adjustments to the tune.  Being back in school I find myself driving a little more responsibly... which is when I started to notice the surging, I'm not surprised the car likes to be driven more aggressively.


 
I'm in a similar boat,
updated wheels, and shuddering/surging
also took it in for a torque converter concern.. passed with flying colors.
noted during the issues the throttle plate is being commanded open and closed causing the bov's to open.
requesting an updated tune via Livernois... however they "haven't tuned a updated turbo car yet"
I'm in Michigan and this is the reason for using them but is not looking so good for an email tune from them and they are months out for dyno time.... and at steep cost.  while i know this will be the best for the tune... timing is everything.

Randy
 
Well some of the problem if you want to call it that is the fact that there are now quite a few options of turbo and compressor wheel upgrades. And they are all mostly different. I've seen some ebay wheels that are actually very good but some that do not seem to change much if anything at all(which is a shame).

It gets complicated because of the boost control and drive by wire and torque logic that the ecoboost uses. So you are requesting a torque command from the accelerator pedal, that gets translated into a desired airflow/load. That needs to match with what the new compressor wheels are moving in terms of airflow.

So that's where remote or dyno tuning can be tricky because some of these wheels aren't having the result that you anticipate because some are good and as advertised and some are not. But that's the point of tuning!..Calibrate the ECU for the hardware!

And also a big factor and also in this case is OP also had upgraded wastegate springs and actuators. Unless you are doing a turbo upgrade I usually discourage this. 1: because there usually is just no need because they raise the minimum boost allowed and 2: because it requires a remapping of the wastegate duty cycle tables when there is no need to typically raise the minimum boost pressure. There is a time and place but usually not for the 3.5 eco...Since we really only run up to 17 psi...The OEM boost control has not problem raising boost to those levels with the stock springs of 4-5 psi

 
AJP turbo said:
And also a big factor and also in this case is OP also had upgraded wastegate springs and actuators. Unless you are doing a turbo upgrade I usually discourage this. 1: because there usually is just no need because they raise the minimum boost allowed and 2: because it requires a remapping of the wastegate duty cycle tables when there is no need to typically raise the minimum boost pressure. There is a time and place but usually not for the 3.5 eco...Since we really only run up to 17 psi...The OEM boost control has not problem raising boost to those levels with the stock springs of 4-5 psi
Click to expand...

I remember you telling me this when the CHRAs and wastegates were installed.  I called the shop to see if there was one or two springs in the wastegates, unfortunately I believe it was just the one 7psi spring in each... and I didn't have the heart to wait and order 4-5psi springs to replace them lol. 
 
SHO9987 said:
AJP turbo said:
And also a big factor and also in this case is OP also had upgraded wastegate springs and actuators. Unless you are doing a turbo upgrade I usually discourage this. 1: because there usually is just no need because they raise the minimum boost allowed and 2: because it requires a remapping of the wastegate duty cycle tables when there is no need to typically raise the minimum boost pressure. There is a time and place but usually not for the 3.5 eco...Since we really only run up to 17 psi...The OEM boost control has not problem raising boost to those levels with the stock springs of 4-5 psi
Click to expand...

I remember you telling me this when the CHRAs and wastegates were installed.  I called the shop to see if there was one or two springs in the wastegates, unfortunately I believe it was just the one 7psi spring in each... and I didn't have the heart to wait and order 4-5psi springs to replace them lol.
Click to expand...

No that’s all good I was just saying that it’s a factor and a lot of people think you can just change the springs and actuators and it’s a non issue...you did a turbo upgrade so nothing wrong with what you did...but I wouldn’t do springs  for no reason

But if you were trying to hit 30 psi and had 4 psi springs then that wouldn’t work lol...the boost control hardware in this car probably wouldn’t allow that
 
I will add my recent experience with this.  My Flex was off the road for quite some time because of really bad shuddering.  The dealer diagnosed as a failed torque converter, 140k on the odometer.  I installed a Ford OEM reman torque converter, a used transmission with 60k miles with solenoid pack and a new valve body.  Upon initial drive tests, I could see my RPMs fluctuating up and down and also feel surging when in a high gear with torque converter lockup and at around 45mph.  I confirmed with the Forscan application that the target torque converter clutch slippage was 20rpm, but in fact, I was getting fluctuating slippage up to about 100 rpm.  Knowing all my transmission parts were already replaced, I began to suspect an engine issue.  I checked my EVAP solenoid on the engine for vacuum leakage, but it was fine.  Forscan was showing much higher long term fuel trim on Bank 1 than Bank 2, about 10-14% versus 6%.  I started to suspect an issue with carbon on my fuel injectors causing the problem.  I ran the fuel tank down to about 1/2 a tank and then put in Techron Complete Fuel Injector Cleaner good to treat 20 gallons, and then idled the engine for about 45 minutes.  I then took it for a 10 minute drive, filled the tank with Shell Super gas, and then took it for another 60 minutes drive with multiple speed/rpm scenarios.  By the end of the drive, the fuel trim was starting to come down, the torque converter slippage was substantially reduced and overall driveability improved.  My scans with Forscan during the 60 minute drive show the torque converter slippage greatly improved. 

Bottom line is that this experience seems to validate what I had suspected.  Fluctuating RPMs during torque converter lockup at high load/low speed/low rpm scenarios (e.g. going up a hill in 6th gear at 45 miles/hour with torque converter clutch engaged) can be caused by fueling issues and in particular what I think must be carbon buildup on the fuel injector.  If you are having these symptoms try some top grade PEA based fuel injector cleaner and see if it helps.
 
Any update how it is driving ?  I am getting the shuddering as well and was ready to bring it to the dealer for warranty.  Now I am thinking about putting the stock plugs back in before I bring it in.  Not sure if they would give me crap about having tightly gapped colder plugs. 




abs said:
I will add my recent experience with this.  My Flex was off the road for quite some time because of really bad shuddering.  The dealer diagnosed as a failed torque converter, 140k on the odometer.  I installed a Ford OEM reman torque converter, a used transmission with 60k miles with solenoid pack and a new valve body.  Upon initial drive tests, I could see my RPMs fluctuating up and down and also feel surging when in a high gear with torque converter lockup and at around 45mph.  I confirmed with the Forscan application that the target torque converter clutch slippage was 20rpm, but in fact, I was getting fluctuating slippage up to about 100 rpm.  Knowing all my transmission parts were already replaced, I began to suspect an engine issue.  I checked my EVAP solenoid on the engine for vacuum leakage, but it was fine.  Forscan was showing much higher long term fuel trim on Bank 1 than Bank 2, about 10-14% versus 6%.  I started to suspect an issue with carbon on my fuel injectors causing the problem.  I ran the fuel tank down to about 1/2 a tank and then put in Techron Complete Fuel Injector Cleaner good to treat 20 gallons, and then idled the engine for about 45 minutes.  I then took it for a 10 minute drive, filled the tank with Shell Super gas, and then took it for another 60 minutes drive with multiple speed/rpm scenarios.  By the end of the drive, the fuel trim was starting to come down, the torque converter slippage was substantially reduced and overall driveability improved.  My scans with Forscan during the 60 minute drive show the torque converter slippage greatly improved. 

Bottom line is that this experience seems to validate what I had suspected.  Fluctuating RPMs during torque converter lockup at high load/low speed/low rpm scenarios (e.g. going up a hill in 6th gear at 45 miles/hour with torque converter clutch engaged) can be caused by fueling issues and in particular what I think must be carbon buildup on the fuel injector.  If you are having these symptoms try some top grade PEA based fuel injector cleaner and see if it helps.
Click to expand...
 
Put forscan  on it the last couple days, there are misfires incrementing overtime as I drive it but don't seem to increase while the shuddering is happening.  Like 9 total for a 45 minutes drive.  The other thing I noticing it while going 35-55 or so I seem the actual converter slippage toggling between 1 and 100 or so while I am feeling the shuddering.  The desired converter slippage is like 20 or below while it is doing this.

At highway speeds the desired and actual convertor slippage is 0 or 1.

I guess I will put new stock gapped plugs in and see whats happens. 
 
Blackhawk said:
Any update how it is driving ?  I am getting the shuddering as well and was ready to bring it to the dealer for warranty.  Now I am thinking about putting the stock plugs back in before I bring it in.  Not sure if they would give me crap about having tightly gapped colder plugs.
Click to expand...

I actually do have an update.  90% of the problem was my throttle body.  One possibility was that I likely messed with the positioning screw on the top of it sometime in the past (I don't really remember).  Another possibility was the water/meth, I have sprayed w/m daily for the last 40k miles on this car and have heard that it can sometimes get into the TB housing.  Regardless, I replaced with a new TB and saw a significant improvement in symptoms. 

The surging although much better, was still there.  AJP made quite a few adjustments to the tune, I'm sure he can chime in with all that was adjusted.  I think he allowed a little more slip in the torque converter and adjusted shift points to keep the car out of the troubled surging areas.  After that the car has been running great ever since. 

Even though the transmission fluid is clear/pink and it was blessed off by the transmission shop... I still think it is just a matter of time until the torque converter goes.  The car has almost 100k miles, the last 40k being pretty hard miles.
 
A quick update for me. put the stock plugs in but still had the shuddering and misfires slowly incrementing.  Brought it to the dealer and they spent 3 weeks chasing the misfire counter by replacing plugs/3 new coils and finally escalated to corporate.  Corp had them run some extra tests and they determined it was the torque converter (which I had suggested when I dropped off).  The shudder went away once it was replaced.  Driving the new loaner vehicles gave me the new car bug and I traded my 2011 SHO in on a 2017 MKZ 3.0t AWD on Saturday.  Loving it so far, just need to spend some time researching what I want to mod :)

Stopped at the drag strip 45 mins after leaving the dealer, only got one pass in, 13.7@102.  I'm guessing a full tank of 87 octane and 41 PSI in the tires didn't help.  Hoping for low 13's stock with some good 93 and playing with tire  pressure.
 
Torque converter shudder gone, time slip shudder ...

Glad the dealer and Ford were able to resolve, enjoy!
 
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