[stewbets]

Originally Posted by Dave92N54

Yup, I've noticed for me it seems to happen only when manifold vacuum is -10 to -11 per MHD, I've seen it maybe happen once or twice around -9.8. My next guess is going to be replacing the MAP in the manifold but since it appears to work fine, little weary of just buying a new one.

I have tried cleaning it as well, doesn't seem to make a difference but I can say the little "ball" on the sensor has been stained completely black, guessing it's probably the original.

My MAP only has a few thousand miles on it. Did you try re-flashing using Wadger's tips?

[Dave92N54]

Originally Posted by stewbets

My MAP only has a few thousand miles on it. Did you try re-flashing using Wadger's tips?

Yes I did, no luck

[Silent9n54]

Originally Posted by Dave92N54

Yup, I've noticed for me it seems to happen only when manifold vacuum is -10 to -11 per MHD, I've seen it maybe happen once or twice around -9.8. My next guess is going to be replacing the MAP in the manifold but since it appears to work fine, little weary of just buying a new one.

I have tried cleaning it as well, doesn't seem to make a difference but I can say the little "ball" on the sensor has been stained completely black, guessing it's probably the original.

find a used throttle body and i bet it fixes your problem, they are not too expensive. Thank me later

[Dave92N54]

Originally Posted by Silent11N54

find a used throttle body and i bet it fixes your problem, they are not too expensive. Thank me later

Already looked, found one at a local used parts shop out of a wrecked car. Going to look at it later, if it doesn't make a rattle noise i'll buy it. They want like $90 for it, pictures show it looking a little rough though so don't have much hope for it's condition.

[Silent9n54]

Originally Posted by Dave92N54

Already looked, found one at a local used parts shop out of a wrecked car. Going to look at it later, if it doesn't make a rattle noise i'll buy it. They want like $90 for it, pictures show it looking a little rough though so don't have much hope for it's condition.

i chased down this problem for weeks, changing boost solenoids, fuel regulator, vanos solenoids, and did walnut blast and swapped throttle body and it was gone.

[Dave92N54]

Originally Posted by Silent11N54

i chased down this problem for weeks, changing boost solenoids, fuel regulator, vanos solenoids, and did walnut blast and swapped throttle body and it was gone.

Just left the shop with the new TB. Does not rattle one bit. I'm so excited to get home and throw it in.

[Yam_440i]

Please keep us updated with that annoying surging issue. If the new throttle body fixes it, I'm buying one right now

[Dave92N54]

Originally Posted by Yam_335i

Please keep us updated with that annoying surging issue. If the new throttle body fixes it, I'm buying one right now

I'm not going to say anything definitive yet but seems to be fixed. I was only able to take a short drive, I'll take another later when it cools down. It's 101°F outside right now.

I would hold off on anything until tomorrow, i'll be driving about 3-4 hours. I'm still a little skeptical, on my short drive I very briefly saw some behavior as if it was going to surge but never felt anything, could just be me being paranoid. Hopefully tomorrow goes smoothly, otherwise I just wasted ~$100

[E90lmao]

So I finally had time to try and log this, this is what I have so far. My rpm stays pretty constant, this was done with cruise control to eliminate the pedal itself from the test. Not sure if these are useful numbers, are there any other parameters I should add?

https://datazap.me/u/e90lmao/log-162...8;data=1-2-3-7

[Dave92N54]

Well, i'm calling it fixed for now. Drove almost 200miles today and didn't seem to do it. I had the gauges up for a little while (needed GPS up for most LOL) and I did see it surge, but I used to see 13.8-15.1 or so on the AFRs, one bank after the other. When I saw it today, it was only like 14.2-14.8.

[Dave92N54]

Originally Posted by E90lmao

So I finally had time to try and log this, this is what I have so far. My rpm stays pretty constant, this was done with cruise control to eliminate the pedal itself from the test. Not sure if these are useful numbers, are there any other parameters I should add?

https://datazap.me/u/e90lmao/log-162...0&data=1-2-3-7

Link doesn't work seems like

[E90lmao]

Hopefully it was a setting thing but this link should work..

https://datazap.me/u/e90lmao/surging?log=0&data=1-2-3

[E90lmao]

Originally Posted by Dave92N54

Well, i'm calling it fixed for now. Drove almost 200miles today and didn't seem to do it. I had the gauges up for a little while (needed GPS up for most LOL) and I did see it surge, but I used to see 13.8-15.1 or so on the AFRs, one bank after the other. When I saw it today, it was only like 14.2-14.8.

So you think it could be the throttle body itself? I really want to know why mine and yours made noise when the new one doesn't. I wonder if something common has broken or something dislocated itself..

[Dave92N54]

Originally Posted by E90lmao

So you think it could be the throttle body itself? I really want to know why mine and yours made noise when the new one doesn't. I wonder if something common has broken or something dislocated itself..

Well, within the black box on the side of it if I remember correctly are some gears which control the throttle blade and are used for idle, since we have no IAC. I'm guessing something in there gets loose and that's why we see the issue sometimes, and why it's at conditions similar to idle (low throttle).

There are definitely other things that cause these symptoms too though so, who knows.

[Silent9n54]

Originally Posted by Dave92N54

Well, within the black box on the side of it if I remember correctly are some gears which control the throttle blade and are used for idle, since we have no IAC. I'm guessing something in there gets loose and that's why we see the issue sometimes, and why it's at conditions similar to idle (low throttle).

There are definitely other things that cause these symptoms too though so, who knows.

glad you listened and got it sorted out

i knew mine was fixed within 30 sec of driving as the low end acceleration improved greatly and was smooth as butter !!

[E90lmao]

Originally Posted by Silent11N54

glad you listened and got it sorted out

i knew mine was fixed within 30 sec of driving as the low end acceleration improved greatly and was smooth as butter !!

I'm starting to think it's my TB, looking for a replacement immediately. While idling I can hold the throttle down to around 1500rpm and without changing throttle position the rpm revs up a bit passed 1500 then drops down under 1000 and keeps bouncing around or hunting I think is the term.

[Yam_440i]

My map sensor on the inlet wasn't tightened down properly, after securing it properly, I think this issue may have gone.

It's a really weird one!

[Spyro235]

I had steady state surging on 3-7% throttle way back when- I'm the poster of a couple surging threads a few years back. What solved mine ended up being o2 sensor replacements- Replacing seemingly perfectlty good sensors fixed it. If I reset my o2 adaptations it would go away until it relearned the behavior- I finally sucked up the cost, replaced all 4 at once, and it totally went away. It was SUPER annoying to me as I had a 110 mile a day highway commute and it would sit there and oscillate the entire time.

[E90lmao]

UPDATE: I took apart my throttle body and it was completely fine, the knocking sound is normal, if you take it apart you'll see what I mean. I then replaced the intake manifold and throttle body gaskets, that didn't do anything. During the whole trouble shooting process I've been running a bottle of chevron techron injector cleaner (2) and a single bottle of liquimoly injector cleaner for 3 cycles a few fill ups spread apart and of all things that has fixed my issue completely... guess the cheapest solution is worth trying first before throwing money at the thing! Goodluck to everyone with this issue

[_N54]

I had this issue, but it wasn't so severe. It was annoying though when cruising on the highway. I installed RB TD04 turbos and 4 new oxygen sensors and the problem has gone away. Not sure what fixed it lol and it's hardly been about 1,000 miles so who knows if it will be back or not.

[Dave92N54]

Originally Posted by _N54

I had this issue, but it wasn't so severe. It was annoying though when cruising on the highway. I installed RB TD04 turbos and 4 new oxygen sensors and the problem has gone away. Not sure what fixed it lol and it's hardly been about 1,000 miles so who knows if it will be back or not.

I'll have to take a look at my 02 voltages after work today. They're all less than a year old. My secondaries are a set of the universal sensors used by Vehicular DIY. I wouldn't put it past them being bad, I got them off amazon. They seem to work though. I wouldn't put it past my wiring skills either. Should have just bought OEs. Primaries are on warranty as well.

I've also considered that it may be a result of my loose ass wastegates. I've adjusted the rear but the front is not having it.

[stewbets]

Originally Posted by Dave92N54

Well, i'm calling it fixed for now. Drove almost 200miles today and didn't seem to do it. I had the gauges up for a little while (needed GPS up for most LOL) and I did see it surge, but I used to see 13.8-15.1 or so on the AFRs, one bank after the other. When I saw it today, it was only like 14.2-14.8.

Hey Dave, is your fix still holding up?