Another tip-in jerking question........

jpjackson · Post by **jpjackson** » Mon Jan 04, 2010 3:11 pm

i just played one of your logs and noticed your afrs jumping all over the place. is this where your problem is? just curious

thething96 · Post by **thething96** » Mon Jan 04, 2010 4:38 pm

The reason the afr's on the log look so erratic, is because the day I was datalogging, it was raining and snowing. Some water went inside the connection between the o2 sensor and the wideband gauge harness. I had another aem wideband do the exact same thing whenever it rained. I'll post new cal and log a.s.a.p.....

thething96 · Post by **thething96** » Thu Jan 07, 2010 11:53 am

Well, last night I finally got to doing a compression test... Cylinder 1: 200 Cylinder 2: 190 Cylinder 3: 205 Cylinder 4: 205 I thought for sure that cylinder 3 would have the least amount of compression, but I guess is 2 this time. As far as I can tell, compression difference is not that much, not enough to create that issue. It started snowing real bad today, so I'm going to try a new throttle body and post cal and log...

Post by **Bugermass** » Thu Jan 07, 2010 11:05 pm

dude.. .. you need to turn off closed loop, and TUNE the part throttle fuel maps.. I metioned this in another post already.. your part throttle map is 95% sure causing your problems.

thething96 · Post by **thething96** » Fri Jan 08, 2010 2:34 am

I did try close loop off, but it doesn't change a thing. The problem happens well above close loop limit. Never gave any problems before, in between, or right after close loop going to open loop.I tried a buddys skunk2 throttle body, but that thing is a p.o.s. It had a major vacuum leak, so I installed my tb with his map sensor. I did another log. On this log, youll notice close loop on until 350 mbar. when I did the log, the spots on the log that had the jerking were on 4th gear, and I kept it as steady as I could on 2000rpm. Also made throttle increase at a very slow rate so that things can be seen earier. Just wished dataloging would log faster, because there's a couple of spots where the car leaned out when the bucking happended and it wasn't captured on the log. But looking over the log, this is happening in between 6-8% throttle, and also noticed it happening in between 420-470 mbar. Some points on the log where the car would jerk, at times the car leans out real bad, but at other times, the afr difference is only about half or a point difference(from 14.0 afr to 14.5-15 afr) so it doesn't seem to be totally afr related. Gents, take a look .....

thething96 · Post by **thething96** » Fri Jan 08, 2010 2:41 am

for some reason, I can't seem to be able to load the log. I'll keep trying...

thething96 · Post by **thething96** » Fri Jan 08, 2010 9:52 am

log...

ninezeroteg · Post by **ninezeroteg** » Fri Jan 08, 2010 11:31 am

^ I have to agree with Bugermass. Running in closed loop is just gonna make the problem impossible to find. It's making corrections to fix what's wrong with your fueling, which is where your problem most likely is. How are you ever gonna find what's causing this when you have a correction trying to fix it? Turn it off til you get this figured out, or you never will. Get your open loop fueling dialed in, and if it's still doing it, people will actually be able to help you find out why. Also, disable fuel cut for vacuum leak is enabled. That's not helping things either.

thething96 · Post by **thething96** » Fri Jan 08, 2010 1:09 pm

Ok, yeah sorry, I didn't really know what bugermass was trying to say. I'll disable closeloop and also the vacuum leak fuel cut, and I'll post tonight, thanks.....

thething96 · Post by **thething96** » Sat Jan 09, 2010 1:14 pm

I have a couple of logs ready, but just double checking. I should have closeloop disabled, fuel cut and vacuum leak fuel cut desabled, right? Or is there something else I should change to get a good log for diagnostics? Thanks....

ninezeroteg · Post by **ninezeroteg** » Sat Jan 09, 2010 1:40 pm

Closed loop needs disabled. Fuel Cut needs to be enabled. You had it disabled in the vacuum leak disable check box. Other than that, you need to do your best to tune the fueling in your low/medium load cruising areas. If the fueling isn't spot on, it's going to cause issues other places in the map. Here's an example: Say you have too much fuel at around 419 mBar and 2000 rpm... That one place having too much fuel can make other areas in that vicinity seem to have too much fuel as well. So you notice too much fuel in that general area, and take some out everywhere around it. Then, when you're cruising around later, and stay in an area for long enough to stabilize, it reads lean (because you took fuel out there due to another cells overfueling). The only way you can make sure your fuel is correct is to hold it at that load, and that rpm long enough for it to stabilize, clear your log, then take a reading. Make a change, let it stabilize, take another reading. That's the only way to get it right. Once your fueling is correct, I would almost bet that your jerking issues will stop. Have you messed around with the timing maps at all? Too much timing in the low load areas can cause a jerking at low loads too.

thething96 · Post by **thething96** » Sat Jan 09, 2010 7:02 pm

timing is pretty much close to stock. I'm using stock type r timing, just smoothed it out. But when most people make low rpm street tunning, what gear is the best one to use? Is it 4th like full throttle(on b series transmissions)? Thanks...

ninezeroteg · Post by **ninezeroteg** » Sat Jan 09, 2010 7:14 pm

Use 3rd for all. Also, if you can't get rpms below say 1500 stabilized to take a good reading, you can at least be fairly confident that rpm's that are less than where you can get it stabilized would want a little less fuel.

Post by **Bugermass** » Sun Jan 10, 2010 3:05 am

I wouldn't try to hold steady state with the stock honda ECU, theres too much stuff going on to get a good stable reading that will translate well while under acceleration.. Your best bet is to get low in the RPMs, set your foot at a fixed throttle % then just let the car accelerate on its own.. Do this multiple times at the same TPS % .. Then repeat at a higher TPS value.. Once you get a good solid portion of the map logged, you can go and make changes then do it all over again.. Make your changes about half of the actuall value its off. So if a group of cells iis off 10%, change it 5-8%.. Change cells in groups where the values are simularily off, then you can make an educated guess as to where oddball cells should be by looking at the surrounding cells.

thething96 · Post by **thething96** » Mon Jan 11, 2010 4:59 am

Here's the new cal and log. On this cal, I decided to add more fuel on the spots where it starts to jerk, which is between 400-500mbar. I added a lot more fuel, as you can see on the log. The jerking got a lot better, feels less harsh, but afr's are waay to rich for that amount of load. I tried to make it a little leaner, but then it would start getting worse. Also noticed that the car has more issues when it's warmed up and has been running for some time. When it's cold, there is no issue what so ever, but when it gets to 140 degrees and higher, it starts again. As previously said, afr's are not always related. Even after adding this much fuel, there's still some bucking going on. When going at 12.0 afr, the car will jump to 13.0 sometimes and still have some jerking, so that's that.....Thanks.......