jagster936
Veteran Member
Sounds interesting, subscribing
Ack! I missed the other spreadsheet pages! But, I still think that the requested fueling is higher than I have seen for stock: I have data from the son's Golf, which, at the time I gathered data, was a perfect runner, and I see a max of 41.8 mg/str.I'm no professional, but the 45 mg/str appears at the lower RPM's but at the 3000 RPM mark they are within spec of 40.0-42.0 mg/str.
Though a value that I believe is out of spec on block 008 is the IQ MAF Limit @ 3000 RPM. The log shows 32.8 mg/str and spec shows it should be 36.0-39.0 mg/str. Not sure how to interpret this though.
Yeah, if I was logging then it would have been 3rd gear. I'm guessing that it was a stock tune at the time: fueling is maxed around 37 mg/str (car now has a Stage 3 tune, with same T4 nozzles, in which case I figure fueling is now substantially higher); log of my car shows max fueling around 49 mg/str - Stage 2 tune with DLC520s.IQ MAF = Smoke Limitation (last column on block 008 data log)
Was the data log taken while in 3rd gear at WOT on your sons car?? Also, does his car have a tune or any mods?
I agree, the boost drops off around 3000 RPM.
I guess is could be sticky vanes, probably pull the down pipe off to check that, I had manually stroked the vanes, but I will check again.
Another thought is that it is under fueling around that RPM.
Also, I was looking at the time stamps vs RPM from your sons car and mine and I noticed that his went from 1900-3800 in about 4 seconds, mine got to 3800 in about 9 SECONDS....now I know it is a DOG! Again assuming your car data log was in 3rd gear.
Performance-wise everything was great, on the wife's car, except that there was a lull around the 3,000 rpm mark, kind of like it was running out of fuel, flat-lining and then pulling back out of it and resorting to full boost/power. I'd cleaned the intake, EGR and intake ports in the head, so all was clean there.That would be interesting seeing logs of all the blocks on her car. Also, how could you tell the vanes were sticky around 3k besides pulling the exhaust and watching the movement of the vanes?
I do plan do check them out once I get back from a work trip.
Work backward from the vanes. Actuator. Hoses. N75. Vacuum pump. I'd still wonder whether there could be a boost leak happening.I was really hopeful it was sticky vanes but they are as free as one could hope for, even got the car hot to see if it caused them to stick any and they are super easy to get full travel from.
Any other ideas???
Been like this since I've had it. I've redone the timing twice, once when I did the belt job and second when I did the cam and liftershas it always been like that? if it was like that when you got it could be a bad timing belt job where vagcom will show it is in time but... Timing is set based on crank-to-IP positioning. You still have the cam, and the cam gear could be off.
Verified the N75, new vacuum hoses, checked vacuum up to N75 with a gauge and holds.Work backward from the vanes. Actuator. Hoses. N75. Vacuum pump. I'd still wonder whether there could be a boost leak happening.
Testing it from the top where it connects to the N75 would also check the line going down to the actuator.I haven't pulled a vacuum directly on the actuator due to it holding boost as well as it responds well to the requested on the graph.
But willing to try if it is felt that it could be an issue.
I found a boost leak spraying soapy water on the tubes and connections.I will hook up some pressure to the system and see of i have a boost leak somewhere.
I decided to chart the IQ values from block 8 vs the boost values from block 11 and that the IQ via MAF follows the actual boost trend almost identically so I could see fueling being effected by the boost issue because of what the MAF is seeing.
This is about the same as I get.Okay, got some testing done.
Checked the turbo actuator with a hand pump and hooked up just after the N75. Thr actuator responds smoothly and no jerking when pulling a vacuum on it.
Also, at idle the vacuum after the N75 was at 20 in-mg and at WOT the vacuum just after the N75 got down to 10-13 in-mg
Can you recheck my numbers? The gauge was out of calibration and so are 6 in-mg lower.This is about the same as I get.
I'm going to look at the boost log again, though UhOh is better with it.
Let me throw this out there if I may: According to "factory specs" you turbo actuator should not hit the stop--request of full boost--until there is 18" of vacuum applied. If you only have 4" to 7" at WOT that would certainly cause an erratic boost curve.
I do not remember how much vacuum you have anywhere else at idle, but if you do not have at least 22" (24"-25" is better) of vacuum at idle straight off of the pump, then I would consider rebuilding the vacuum pump. It is an easy job to do and all you need is an o-ring.
The turbo is set to 'vent' off the excess boost that the ECM sees that is over allowable boost. So at WOT the more fuel sent into the engine means higher boost so the vacuum drops from the N75 to the actuator opening the vanes in the turbo to help keep the boost under control. The vanes in open position are "venting" off boost like a wastegate setup would.The way it works makes no sense to me.
At Idle I get more vacuum then when I take off and it drops.
I have power as far as I can tell and the only thing I get is slightly lower MPG for the all highway driving I did for my last 2 jobs.
Use to get just over 50 MPG w/o the AC.
Last several years it dropped varying 45 to 47 or so.
Last job was 1 mile to the highway, 30 miles to the exit (1 toll booth in between) and 1 mile to the parking lot.
I should have gotten 50+
My boost gauge easily goes to 20-23 LB (US) boost if I punch it.
Some day I have to lengthen again, it was even higher when I installed the actuator.