Vanos Rebuild Start Hesitation

[sapote]

Battery is new as of 3 months ago and has no issues cranking, so I figured it would be fine. Ironically I changed the battery thinking it was the issue in the first place

I can add voltage to the log but with all these PIDs I'm pulling its pretty slow at refreshing so not sure how accurate the data is. What am I looking for exactly with battery voltage, dips while driving?

Everything is depending on DME voltage, i.e. injection amount, fuel pump rate. We want to know how stable is the DME voltage; a new batt with bad wire connection can cause jumpy DME voltage.

Remove the not needed pid: gps car speed, intake temp, coolant temp, MAF, as we already know they are good.

[sapote]

Log a drive at fwy speed coasting with smooth throttle. The absolute throttle position pid jumped to very high then dropped to zero -- data look so strange.

[jamesfoley]

Log a drive at fwy speed coasting with smooth throttle. The absolute throttle position pid jumped to very high then dropped to zero -- data look so strange.

Yea I honestly don't know if I trust the absolute throttle position in that log. There were times I had my foot on the throttle and it was coming back as 0 on the gauge. If I really had no value coming out of the pedal then the car wouldn't be accelerating and I would 100% have a code, but it drives fine so 🤷

I'll pull some PIDs and get some more logs of throttle position. Is battery voltage just "Input voltage read by the scan tool" in the PID list?

[jamesfoley]

Bit of a side question, but does anyone know the legitimacy of shadow codes within BMW Scanner?

The DME always has two "Internal fault" shadow codes that do not clear, 63 [099] and 59 [089], and I also get shadow codes for "Ignition Coil, cyl. 4" 32 [050] (multiple of the same code) which do clear, but always come back.

[jamesfoley]

sapote Voltage looks rock solid here https://datazap.me/u/jamesfoley/e46-...=0&data=1-6-13

Tried to be reasonably smooth with the throttle but its still pretty jumpy

[sapote]

With the new MAF, do a log for cold start idle with adding Secondary air status pid (to see when SAP turn on and off) and all the o2 sensors, coolant temp, fuel status. I suspect the pre cat sensors are bad leading to fuel system status 8.
So the log should show pre cat sensors dip down below 0.1 during SAP running (too much oxygen) and swing to 0.8 when SAP turned off.

The DME voltage looks great.

[jamesfoley]

With the new MAF, do a log for cold start idle with adding Secondary air status pid (to see when SAP turn on and off) and all the o2 sensors, coolant temp, fuel status. I suspect the pre cat sensors are bad leading to fuel system status 8.
So the log should show pre cat sensors dip down below 0.1 during SAP running (too much oxygen) and swing to 0.8 when SAP turned off.

The DME voltage looks great.

Cold start log as requested with secondary air pump status: https://datazap.me/u/jamesfoley/e46-...-9-10-11-12-13

For what it's worth, its consistently starting fine from cold now ever since I swapped the MAF. Only seems to be the warmer starts that it struggles with now. The log above it started instantly with no issues whatsoever after sitting all night.

[sapote]

Cold start log as requested with secondary air pump status: https://datazap.me/u/jamesfoley/e46-...-9-10-11-12-13

For what it's worth, its consistently starting fine from cold now ever since I swapped the MAF. Only seems to be the warmer starts that it struggles with now. The log above it started instantly with no issues whatsoever after sitting all night.

This shows pre cat bank1 sensor1 didn't drop below 0.1v during the SAP running, while bank2 sensor1 was well below 0.1v and it looks much better than bank1 sensor. So I think it's worth to replace B1 sensor1 and hope it will solve the fuel status 8 issue. Do you have stock DME software or aftermarket tuned version?

One odd thing: I never seen the secondary air status starts at 4 then drops to 1 to run the air pump. It normally starts at 1 in cold ambient and then switches to 4 after pump turned off.

[jamesfoley]

This shows pre cat bank1 sensor1 didn't drop below 0.1v during the SAP running, while bank2 sensor1 was well below 0.1v and it looks much better than bank1 sensor. So I think it's worth to replace B1 sensor1 and hope it will solve the fuel status 8 issue. Do you have stock DME software or aftermarket tuned version?

One odd thing: I never seen the secondary air status starts at 4 then drops to 1 to run the air pump. It normally starts at 1 in cold ambient and then switches to 4 after pump turned off.

As far as I know I have a stock DME. Is there any way to check this?

Its an EU car if that makes any difference? Also I started logging before I started the car, possible the PID didn't update quick enough when it started?

[sapote]

Read the DME software version to verify it's stock.
The SAP status was was 4 (no pump running) after engine running, and then switched to 1 (pump running). The DME should have detected the cold ambient with key turned on and before cranking. it's odd but I don't think it caused any problems.
One more thing: during driving, the post cat sensors follows the pre cat sensors -- acted like the cat efficiency were down and unable to clean the exhaust gas; Cats are not cheap so hopefully the mixture was so bad that the cats couldn't clean it all.

[jamesfoley]

Read the DME software version to verify it's stock.
The SAP status was was 4 (no pump running) after engine running, and then switched to 1 (pump running). The DME should have detected the cold ambient with key turned on and before cranking. it's odd but I don't think it caused any problems.
One more thing: during driving, the post cat sensors follows the pre cat sensors -- acted like the cat efficiency were down and unable to clean the exhaust gas; Cats are not cheap so hopefully the mixture was so bad that the cats couldn't clean it all.

MSS54 Software Version is 211322001301-J424 if that's what you're after?

I could understand if the cats aren't as efficient at 22 years old, but that's another bridge I'll cross once the car is running correctly. As far as I know post cat O2 are just to monitor cat efficiency right, so they're not going to change how the car runs

[sapote]

MSS54 Software Version is 211322001301-J424 if that's what you're after?

I could understand if the cats aren't as efficient at 22 years old, but that's another bridge I'll cross once the car is running correctly. As far as I know post cat O2 are just to monitor cat efficiency right, so they're not going to change how the car runs

I don't know much about the software version; on the cats, they should not affect engine running unless they are clogged up, but so far I don't see the evidence (post cat sensors with stuck lean signal at below 0.5v)

[jamesfoley]

I don't know much about the software version; on the cats, they should not affect engine running unless they are clogged up, but so far I don't see the evidence (post cat sensors with stuck lean signal at below 0.5v)

Googling the version number doesn't seem to yield many results which is odd.

At 120k miles it could probably benefit from two new pre cat O2 sensors so I'll get them both done once the fuel regulator is sorted. Just trying not to change everything at once mainly to lessen damage to my wallet...

[sapote]

Why do you need to work on the fuel regulator? What’s the measured pressure at idle?

[jamesfoley]

Why do you need to work on the fuel regulator? What’s the measured pressure at idle?

Honestly it was just the next step after I did the pump. I have the regulator, just needed a shop with a lift that could fit it for me. Was also the next recommended step by the shop who sorted my VANOS timing so it’s booked in for Saturday.

Zero idea on pressures as I’ve not had them checked, though will hopefully get some readings on Saturday.

Do you have any idea if a DME update would help?