Causes for surging under throttle

[Jersey_M3]

Hello all, Im trying to diagnose an issue I have with my car. Ive recently started to encounter more surging than usual throughout the power band. The 2k one took place ever now n again but under full load I had it at 5k. I was wondering if anyone had an idea as to why this happens. I have no codes or pending codes on the car and have driven it 3,000 miles in the past month or so. Currently sitting at 128,000 miles. I redid the vanos at 118,00 miles: turbotoy hub, arp camshaft bolts, besians reseals, and upgraded chain guide. Used the BMW bridge, no knock off. I did not purchase the besians solenoid because, well i have no codes. I also did rod bearing work at 125,000 miles, with all OE parts. At the same time I changed the fuel pump, fuel filter, and all new OE injectors. Air filter and throttle bodies were cleaned as well. Any thoughts?

[Arith2]

The best thing to do would be to look at data while the car surges. I recently had a faulty fuel system code over a stupid MAF.

[Lukem3]

Vanos hesitations would happen under 3k usually. Anything after 3k is usually going to be af related, ping or a misfire

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[Arith2]

Hello all, Im trying to diagnose an issue I have with my car. Ive recently started to encounter more surging than usual throughout the power band. The 2k one took place ever now n again but under full load I had it at 5k. I was wondering if anyone had an idea as to why this happens. I have no codes or pending codes on the car and have driven it 3,000 miles in the past month or so. Currently sitting at 128,000 miles. I redid the vanos at 118,00 miles: turbotoy hub, arp camshaft bolts, besians reseals, and upgraded chain guide. Used the BMW bridge, no knock off. I did not purchase the besians solenoid because, well i have no codes. I also did rod bearing work at 125,000 miles, with all OE parts. At the same time I changed the fuel pump, fuel filter, and all new OE injectors. Air filter and throttle bodies were cleaned as well. Any thoughts?

Do you have a stock tune? Any surging is unusual.

[Jersey_M3]

Do you have a stock tune? Any surging is unusual.

Yes stock tune. All stock motor

[Jersey_M3]

What is the easiest or best way to pull log data off the car?

[liam821]

What is the easiest or best way to pull log data off the car?

Dirty IACV, bad MAF, or vacuum leak would be the top suspects.

[mrgizmo04]

What is the easiest or best way to pull log data off the car?

Find jfoj thread on e46fanatics about obdfusion. It logs quite a few PID.

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[heinzboehmer]

What is the easiest or best way to pull log data off the car?

BMWLogger: https://bimmersoftware.com/bmwlogger

or

Testo: http://www.bimmerforums.com/forum/sh...ime-graph-view

[liam821]

BMWLogger: https://bimmersoftware.com/bmwlogger

or

Testo: http://www.bimmerforums.com/forum/sh...ime-graph-view

I used Testo to do test my CSL map sensor. It's a pita to get working, because Windows, but it works great once it does.

[Arith2]

I used Testo to do test my CSL map sensor. It's a pita to get working, because Windows, but it works great once it does.

I'm not looking forward to figuring that one out. What sensor are you using?

[sc_tr0jan_m3]

Might be a stupid suggestion but have you tried clearing your adaptations yet?


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[liam821]

I'm not looking forward to figuring that one out. What sensor are you using?

I ordered a Bosch 0261230101 - it's the same part as the OE BMW CSL sensor but since it's a Bosch part number it's 1/3 the price. You can get it on Amazon for $41.

https://www.amazon.com/Bosch-Original-Equipment-0261230101-Manifold/dp/B00BL747DC

[Arith2]

I ordered a Bosch 0261230101 - it's the same part as the OE BMW CSL sensor but since it's a Bosch part number it's 1/3 the price. You can get it on Amazon for $41.

https://www.amazon.com/Bosch-Origina.../dp/B00BL747DC

I ordered the sensor for the M50's manifold as it showed a cross reference in part numbers. Visually it's identical to the CSL one. Hopefully the internal resistance is the same. I'm only out $17 if it's wrong. The one I got is VNE so hopefully is doesn't crap out. It's all chinese garbage anymore.

[liam821]

I ordered the sensor for the M50's manifold as it showed a cross reference in part numbers. Visually it's identical to the CSL one. Hopefully the internal resistance is the same. I'm only out $17 if it's wrong. The one I got is VNE so hopefully is doesn't crap out. It's all chinese garbage anymore.

Once you get it working, you can use Testo to verify it's working correctly and returning the correct voltages.