CHADisBAD

i read all about the hiccup issues on this forum, and that is exactly what i told jason and tony @ BIP last week, because i had read they had the hiccup problem resolved. tony called me yesterday said something is up with the ECU and need to be investigated more, i then told him well the car was running fine besides the hestitation/hiccup. so im like you, i dont see how the ECU could be bad when this is a common problem.

last night i seen where this thread was brought back to life, and these symptoms sound pretty much the same as well, other than the map sensor/key cycle.

Hulk

Yes sir, as soon as some cars go to a bigger tb than 80mm they get this issue, I have heard that bip on this forum fixed the issue and I hear so have EC

mrweelr

I'm getting closer to resolving these issues with my S550 82mm TB. Make sure you raise the idle in P and D to the max limit in STAR and go into ME > ADAPTATIONS and reset adaptations for sensors, mixture and do a default initialization. Also do the TB recalibration with the ignition on/off disconnect/reconnect cable process. Your car may run much better after you do these things. If you have no vacuum leaks anywhere and you've triple checked all gaskets and hoses with brake/carb cleaner and/or done a smoke test, then I agree this is most definitely tune related. Doing those things above in STAR reduced the bucking/hiccup issue dramatically on my car, but it's still there slightly on tip-in. Will post results after I change the MAP sensor next weekend. Skeptical that will make a difference, but it's worth a try.

Karlson

any updates?

mrweelr

I received the new tune from BIP, but can't get that POS Galletto software to connect or write to my ECU. Going to work on this with Tony and will update once I successfully refresh the ECU. The stutter/hiccup issue issue is still ever-present and very annoying in stop and go traffic.

kponti

I haven't read the first page recently so you may have covered this, if so ignore.
But somehow your symptoms sound like mine when I had one of my plug wires loose. The stock wires can be a serious pain in snapping them securely back in place especially when they are old or stock. After having one too many of them pop off when driving normally or under WOT (all this started after I disconnected them for TB, then again some months apart for header install), I simply bought a replacement Bosch set from Amazon and I haven't had the shaking hiccuping ever since.

Also popping off is my description for: Its still attached, but when you really push HARD and rotate the wire at the same time, it pops in further. If you pull on any of the wires and they come off with normal everyday force, it was not in properly, it should take enough force that you might have to use a plug remover to take off for it to be in place properly

One last thing....most of these TBs especially the NON Mercedes ones tend to have the Y-pipe (rubber snorkel) propped nice and tight (or so you think) against the TB and not actually slip over sealed like the stock one was. I removed that weird jerry-rigging contraption and used a silicone hose with worm clamps ( ). I think that has gone a long way in eliminating my MAP code (500 plus miles and counting)

mrweelr

KPONTI - Appreciate the suggestions, but this hiccup/bucking issue started a few years ago when I reflashed the car with the first tune. After I installed the 82mm TB, the issue is even more pronounced and makes the car unpleasant to drive. I changed the plugs about 6 months ago and lubricated the plug wires with dialectric grease, they are all snapped on tight. That rubber snorkel is not as tight on the 82mm S550 TB as the stock snorkel was on the stock TB, so I was planning on installing an aftermarket aluminum pipe with cone filter setup and silicone coupler to get rid of that rubber Y, but haven't had time to research aftermarket filter kits. If you were able to get that silicone coupler to seal properly with the MB y pipe, please post some pictures of your setup. I've been getting the P505 - idle malfunction code intermittently and can't find any vacuum leaks anywhere. I'm convinced the bucking/hiccup issue is the tune and Tony is going to help me reprogram the ECU later this week and I'll post an update once it is done.

Karlson

Whats your throttle %?

mrweelr

Ranges between 1.6% and 2.0% at idle in P and D, but I've seen it dip to 1.2% a few times. I already raised the idle in P and D to max in STAR and reset the ECU adaptations and TB calibration. I still get the intermittent P505 code and check engine light. The tip-in bucking issue is constantly there and we will see if the retune fixes it.

Hulk

Tps% too low
Did you try checking down that metal vacuum line to the front of the car?

I was getting the p0505 last week and checked the metal line into the sc and still was getting the code and my tps% was like you , actually mine went lower than 1% at one point.

Followed the metal line to the front and low and behold there was a hole in the line, must have been rubbing on something. Cut the metal line, got a rubber vacuum hose and joined the two parts, all good now.

Karlson

Mine goes into 0.8, is it the lowest can go? I couldn't find a leak, so going to use star to raise it to maximum in p and d to check.

Hulk

Ya mine hit that via obd, on zt2 it was reading 0 since it couldn't show .8

Waaaay too low, did you ever get p505?

Mine was a freak occurrence because I had never gotten that code before, so it had to be a leak somewhere

Karlson

running p505 for past 3 weeks and can't figure out solution

Hulk

Raising the idle is a band aid, there has to be something wrong either with the tb, connections or a leak somewhere

Karlson

at least that helps with getting rid of CEL, sprayed two cans of break cleaner to find a leak, but rpm didn't change at all.

Hulk

What kind of tb is it?

Karlson

Merc one with part number a2731410325 on it

Hulk

I'm sure you have done this but do a tb reset

Karlson

I gave up after 9th time.but still the same thing

Hulk

Damn bro, it's low, have you tried swapping tb or connector?

E55Greasemonkey

I'm having the tip-in hesitation and bucking issue also. If you partly accelerate at the right (wrong) time the car will buck like a bronco! I've learned to drive around the issue somewhat. No codes, ever. Worse when cold. I feel there is not enough fuel given at tip in, as the ECU is calibrated for the smaller stock TB. Not sure if the tuners have access to the part throttle load maps. The solution would be to add more fuel at tip in. You'll notice if you reset the mixture adaptations with STAR the car drives great for a short time until it re-adapts.

mrweelr

I removed the blower for the S550 82mm TB swap and was very methodical and everything was fanatically clean before I reassembled, I also used all new MB gaskets everywhere. The P505 code started right after the 82mm TB and 550cc injectors went in, there are no vacuum leaks anywhere. I sprayed every hose, connection and seam on the top of the engine carb and brake cleaner with the engine idling and it could not alter the idle. I even removed the metal line from the supercharger and reinserted it with some grey RTV along the outside edge where it slides into the rubber grommet at the back of the blower just to be sure it wasn't leaking, made no difference. I've seen my TPS % drop to .8 also from time to time, my understanding is it should be closer to 3%, but raising the idle to max in STAR didn't fix it for me. I even replaced the ridiculous to reach MAP sensor with a brand new Bosch unit shipped direct from Germany and it made zero difference.

The bucking/hiccup issue was there before I did the 82mm TB and 550cc injectors, it's just more pronounced with the larger TB. I will post an update after I get the BIP tune loaded, if it's still there after the tune change, I'll be very surprised. I should not that my car purrs smooth as silk at idle and cruise and is a beast at WOT, but that tip-in hesitation/bucking just takes the joy out of driving it. I will sleep better at night when this problem is fixed.

viper04

Keep us updated! on this.

kponti

Does this car have a blowoff valve?

Hulk

Bypass valve