User Name Remember Me? This isn't a huge deal but I noticed when I hold the throttle at a low speed like cruising in 6th for instance the car has this "surge" effect. The boost will go up and down by 0. I remember back in the day that having the AFR jumping from lean to rich at idle was ideal but I don't recall that being a thing when moving. Like I said, not a huge deal and the car does run phenomenal regardless. I just want to better understand and learn about these things so to diagnose any problems early rather than later.
Thanks for any help. Attached Images. Terry BMS. Looks like normal cruise behavior to me. If you had a surge then PWM would be oscillating. If you want to lower boost during this type of cruise I'd lower menu 12 slightly. Find all posts by Terry BMS.Fixed My Hesitation Issue On My N54 E90 335i
Did you ever correct this issue? My car has done the same thing since I did the BEF. Thread Tools. Contact Us - N54Tech. User Name. Remember Me? Mark Forums Read. Posts: Join Date: Apr Car: i. Send a private message to rhodesman.
Surging while cruising at 1900 RPM
Find all posts by rhodesman. Posts: 1, Join Date: Mar Car: i. Send a private message to trebila. Find all posts by trebila.
Terry BMS Tuner. Posts: 30, Join Date: Jan It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations.
BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. Please click here for more information on legal requirements related to use of BMS parts. AndyG Junior Member. Send a private message to AndyG. Find all posts by AndyG. Posting Rules.Remember Me? Surging or oscillation at light throttle, low rpm.
The problem most commonly manifests when getting under way from a stop light. However, it does not occur every time.
Starting is normal, idle is very smooth once engine is warmWOT is fine, power if excellent and throttle response is normal once at speed. Since I have a manual transmission, the bucking can be finessed without too much trouble but it still bothers the hell out of me.
The car has had recent plugs, the coils were new about 3K miles ago and the injectors were replaced between 5K and 8K miles. VANOS solenoids are very new as are boost solenoids. I'm completely stumped. Appreciate 0.
Private First Class. I am currently experiencing the same problem. I have recently replaced the plugs with a step colder gapped to. I am wondering if this is causing the issue? Though I get no codes.
I had one step colder NGK plugs gapped to 0. No change in the problem. I do get an occasional code which is hard to relate to the problem. It is misfire on cylinder 6 but it only occurs when the engine is stone cold. It happens pretty quickly after the engine is started but is relatively infrequent in its appearance.
It is not related to plugs, coils or injectors since I've swapped all three around quite a bit but the misfire always remains on cyl 6. My car never stalls - I can keep this oscillation think going for quite a while. No misfires ever associated with the oscillation. Should add that I have no obvious vacuum leaks - the cannisters hold a vac for many minutes after the car is turned off and all the hoses were changed to silicone when I installed the inlets and outlets about a year ago.
I have something similar going on. New plugs, coils and index 12 injectors. Car will run great than misfire and stumble. After a bit runs great again. I was getting a lambda code so just replaced the oxygen sensors in front.Forums New posts. Garage New media New comments. Resources Latest reviews. Log in Register.
The one I captured was 3rd gear at about RPM. I have had it happen in 4th and 2nd but it is at different gears. I hold the pedal as still as possible with my foot at rpm and it feels like I am moving forward and backward similar to how you would feel if you pushed on gas then let off, pushed on gas then let off, etc.
I captured a log of it and trying to see if anyone has any ideas. Jan 9, Houston TX. What's your maintenance history? Valve clean, plugs, boost solenoids, vacuum lines, etc. Bump for smarter people to answer, I'm intrigued. N54QC Corporal.
Aug 17, I had the same problem last year and it went away after a few months and then it started happening just recently again. There was several discussions on n54tech including threads I started with logs about it and never got an defined answer other than it might be a hardware issue.
When all of a sudden my car went into limo mode. I check the codes via JB4: 2CF9 - throttle valve potentiometer 1 2CEC - throttle valve actuatorshort locked 2CEE - throttle valve actuatorrunning rough 2CF7 - throttle valve potentiometer 2plausibility in regards to air mass 2D09 - drosseklappe I tried to cleared the codes and they all would come right back.
Restarting the car did nothing nor did disconnecting the battery. I got the codes to clear by holding the pedal to the floor. Assuming this is the the relearn for the pedal. Re start the car and still same issue Now codes read. My thoughts are the throttle body is bad but I'm unsure.
Today after work I'll take a better look and see if a gasket got sucked in the throttle body or if the connection is bad. Anyone have any thoughts? Nov 14, North Wilkesboro. If you have a JB4 with the engine off, ignition on. Do option 1,7 to reset adaptations. Drive around normally with no sudden throttle movements for about miles so the DME can learn normal driving behavior and then do WOT pulls log these too and either post here or send to me But, if you have the time definitely check out your throttle body and make sure everything looks good.
If it looks good and you got some new gaskets on hand go ahead and clean up your Vanos Solenoids as they tend to cause some strange issues if they haven't been clean anyways. Keep me posted.
engine surge, no throttle response, codes! ideas?
I went to over look everything at the throttle body and the connector pulled right off! I have no idea how that could of happened. I did my walnut blasting over 3k miles ago.
Whatever works I guess. Ace Private. Dec 12, 31 Las Vegas. Reset adaptations last night only to have it happen again. Neither a throttle reset or JB4 adaptation reset has worked for me. The problem seems to have developed in the last few weeks. My issue seems to be based on maintaining low, constant throttle openings at high speed regardless of gear.
Shifted down to 5th and 3rd to see if it made a difference. It just bucked harder in lower gears as the RPMs exacerbated the problem. Ffwturbo New Member. Mar 3, 5. Just recently began to get this surge. This began after I removed the throttle body and intake for cleaning and external PCV mod. Have the surge now for over a month.
Looked everywhere for leaks cracks, reflashed tunes, replaced intake gaskets, reset throttle adaptations with pedal and MHD Gonna try to go back to stock tune and see what happens. Aug 13, N54QC Corporal.I noticed a hesitation and roughness between and rpm under acceleration. There are no SES lights or any other symptoms. The car would accelerate through that range well enough but it was very annoying.
It is particularly noticable in 4th through 6th gear. In 1st through 3rd gear the car accelerated too rapily through the rpm range to notice the roughness unless you are looking for it. My car has had the HPFP and all injectors replaced under recall and I paid for new spark plugs about a year ago and it currently has 67K miles on it.
Otherwise the car is great. I took it to the dealer and they confirmed my symptoms I did not tell them that I knew about the 2AAF and the TSB and said I need a new low pressure fuel pump, the one in tank. I asked my service advisor if they were sure.
I said OK but "fuel delivery at rpm is different at each gear and varies with load on the engine.
BOV Setup for your N54
I said "OK, do the repair. After warm up, I started accelerating and the car was still doing the exact same thing. I immediately brought the car back. I am reserving my opinion of this dealer until I have the problem resolved. Everyone can make a mistake. I will update the post as soon as I have resolution. Has anyone experienced the same thing? Your problem sounds to me like a problem I had with ignition coils. It was a misfire and most evident under heavy load in 3rd or 4th gear around 3k rpm.
No codes until later, when the ignition coil went completely south. I am also having the same problem with my car xi 6MT. It happens only at lower RPMs as you stated. It feels like the boost is breaking up under moderate to hard acceleration. I too have had the HPFP and injectors replaced under the recall.
Also, no check engine light and otherwise the car runs great. I haven't had a chance to bring it to bring it to the dealer yet and won't be able to for another week or so because I'm leaving for vacation Tuesday. Please keep us posted, I'd love to know the resolution to this issue. Very interested in final resolution!
Could be as simple as a dirty filter Sooooo, was the LPFP replaced? I just had an injector replaced last week. Now mine is also hesitating between and rpm under highway load acceleration. It won't do it in 1st or second gear when I'm pulling out.