Throttle Delay, intermittant
Thread Starter
Member
Joined: Jul 2018
Posts: 171
Likes: 34
From: USA Tennessee
2008 SL550 R230, 2004 E320 W211
Throttle Delay, intermittant
I have a 2004 E320 with 170K miles.
Sometimes when it is cold, it seems to run a little rough; it idles fine, but it seems a little rough at low RPM and the throttle seems odd at low RPMs (until it is warmed up). Recently, with the car in park, I noticed that the throttle response had significant delays, at times (with the car in park and warm engine) I could punch the throttle to floor, and then release it, and the engine would never come off of idle. I could "blip" the throttle, and again no response. Sometimes it seemed like there was a 1 to 2 second delay from the throttle. Driving the car, the throttle seemed a little sluggish, but not as bad as when in park. Then I re-started the car, and the problem seems to be gone???? I have experienced it again, and it seems that this comes and goes? I don't have any CEL or codes?
I have replaced the plugs and wires, air filter is good.
I suspect either the MAF or the throttle/pedal position sensor. I have searched the forums and found some posts on both of these, but I can't definitively tell if either of these is my problem.
Does anyone have any suggestions on how to test either the throttle position sensor or the MAF? I guess I could try cleaning the MAF, and see if this gets better, but to be honest, I would assume the MAF would NOT be intermittent and I would assume I would get a CEL or code if the MAF was bad/dirty?
Any advice would be appreciated. Thanks.
Lee
Sometimes when it is cold, it seems to run a little rough; it idles fine, but it seems a little rough at low RPM and the throttle seems odd at low RPMs (until it is warmed up). Recently, with the car in park, I noticed that the throttle response had significant delays, at times (with the car in park and warm engine) I could punch the throttle to floor, and then release it, and the engine would never come off of idle. I could "blip" the throttle, and again no response. Sometimes it seemed like there was a 1 to 2 second delay from the throttle. Driving the car, the throttle seemed a little sluggish, but not as bad as when in park. Then I re-started the car, and the problem seems to be gone???? I have experienced it again, and it seems that this comes and goes? I don't have any CEL or codes?
I have replaced the plugs and wires, air filter is good.
I suspect either the MAF or the throttle/pedal position sensor. I have searched the forums and found some posts on both of these, but I can't definitively tell if either of these is my problem.
Does anyone have any suggestions on how to test either the throttle position sensor or the MAF? I guess I could try cleaning the MAF, and see if this gets better, but to be honest, I would assume the MAF would NOT be intermittent and I would assume I would get a CEL or code if the MAF was bad/dirty?
Any advice would be appreciated. Thanks.
Lee
Member
Joined: Nov 2019
Posts: 79
Likes: 7
w211 04 e220
Had almost the same problem,only I was overtaking and suddenly car lost all power,no check engine light etc..Restarted car everything seemed fine,until one day black smoke was coming out like crazy,egr valve blocked/dirty.Would suggest to clean maf throttle and egr.
Thread Starter
Member
Joined: Jul 2018
Posts: 171
Likes: 34
From: USA Tennessee
2008 SL550 R230, 2004 E320 W211
I have cleaned the MAF, and there does seem to be some improvement, but I still feel like there is a slight delay on the throttle at times. I will continue to drive it and report back. If anyone knows of a good way to test the throttle position sensor in the pedal or otherwise, let me know. Thanks.
Lee
Lee
Thread Starter
Member
Joined: Jul 2018
Posts: 171
Likes: 34
From: USA Tennessee
2008 SL550 R230, 2004 E320 W211
I still feel a delay in throttle response, although it seemed slightly improved after cleaning the MAF. However, when I quickly "blip" the throttle in neutral, it still hesitates for about a half second or more for the engine to respond. Still no codes. Using Star SDS (I am a novice, or something less than novice), I tested the MAF, and at idle it is just barely within expected specs (can't remember what the spec is, but I think it was mv, temperature was fine), occasionally going out of spec (but just barely). Second test was at RPM >3500, this tested within the expected results. I'm wondering if my MAF is failing, but is barely within spec enough not to throw any faults?
Interestingly, while running the MAF test at >3500 RPM, I noticed that the car wouldn't go over 4200 RPM in neutral. I saw some other Mercedes posts that this was a rev limiter while in neutral? Is this correct?
At this point, I'm pretty sure either my MAF is failing, or the pedal position sensor is failing? I don't like to throw parts at problems without knowing for sure, but at this point I'm probably going to simply put a new MAF in it (about $120 online for Bosch).
Any thoughts or advice?
Lee
Interestingly, while running the MAF test at >3500 RPM, I noticed that the car wouldn't go over 4200 RPM in neutral. I saw some other Mercedes posts that this was a rev limiter while in neutral? Is this correct?
At this point, I'm pretty sure either my MAF is failing, or the pedal position sensor is failing? I don't like to throw parts at problems without knowing for sure, but at this point I'm probably going to simply put a new MAF in it (about $120 online for Bosch).
Any thoughts or advice?
Lee
Last edited by Leej; Jan 14, 2020 at 11:48 PM.
Newbie
Joined: Apr 2021
Posts: 3
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E240
Hi, I had the same issue I was overtaking and my car went into limp mode and produced the P0101 code.
I done a few checks on the MAF but trying to find info to confirm it is the MAF before I buy the part.
is there a section where someone has done check on the MAF to confirm its dead?
Thanks
I done a few checks on the MAF but trying to find info to confirm it is the MAF before I buy the part.
is there a section where someone has done check on the MAF to confirm its dead?
Thanks
