DIY 2A9A and 3100 on fresh build, stock turbo world record?

[Aaron]

Freshly rebuilt engine with a ported head, Schrick high lift cams, and stock turbos. Might hit the stock turbo world record, but don't really care about that kind of stuff. Onto the issue..

1) Car is slow to start, starts, runs for 2-4 seconds, and dies, regardless of throttle.

2) Unplug only the intake vanos solenoid, car starts and runs normal ish.

3) Swap the intake and vanos solenoids, plug both in, car starts and runs, but throws persistent 2A9A and 3100 codes.

I tried 3 sets of solenoids, no change. Resetting the code while running results in engine dying, slow to restart. The car seems to run good, minus no boost. Any ideas?

 

[R.G.]

Check fuse 37 (30amp) first

 

[R.G.]

Also make sure to clear all vanos adaptations before retesting

Here’s a good article on pinpointing issue

BMW VANOS System Fault Testing and Diagnosing

In this technical article, we will give you the definitive guide on diagnosing BMW variable-valve timing (VANOS) faults.

us.autologic.com

 

[Aaron]

Fuse 37 is good, and vanos adaptations were reset with each new set.

Car would not stay running today until I unplugged the intake vanos solenoid, then it started and ran good (Minus the codes of course).

 

[R.G.]

Need more info dude. First the easy stuff to cross off

Freshly built, as in approx first few starts?

If so, made sure battery doesn’t need a charge and oil level is correct?

No visible sludge (thick goopy shit) oil buildup on oil cap or filter?

You’re scanning using inpa, correct? No codes thrown before car dies?

Do you have a multimeter to check connectors?

Double check DME connection to make sure no pins were bent / skewed as well

 

[R.G.]

I would triple check camshaft sensor placement
Make sure o ring not visible from any angle

BMW E90 Camshaft Position Sensor Replacement | E91, E92, E93 | Pelican Parts DIY Maintenance Article

A bad cam sensor can cause reduced engine power and a check engine light. Here's how to change it out in under 10 minutes.

www.pelicanparts.com

 

[R.G.]

And the crankshaft sensor fuse is a 20amp, fuse #11

 

[Aaron]

Thanks for the info, I'll try the cam sensor next. Although I don't hold much hope, it only has 51,000 miles, and worked on the previous 2 motors this head was installed on. But it never had a Schrick cam before.

Freshly built, did this from the very first start on forward.

Battery and oil level are good, no sludge.

Using MHD for the codes, and is throwing a consistent 2A9A and 3100.

Yes I have a multimeter. All pins visually appear in good condition, and the DME connection was never disconnected.

Again the cam sensor was never removed, however I'll swap it to rule it out since I've got spares.

If the crankshaft sensor fuse was out the car would not run at all, that's a critical component. But it's just a fuse, so easy enough to check.

 

[R.G.]

My money is on crankshaft sensor wiring / vanos connection wires are pinched somewhere.

Let us know what it was once solved please.

@Hydra Performance might have some insight

 

[Aaron]

I don't think it'll be anything to do with the crankshaft sensor, my understanding is that that is a critical sensor needed for the engine to run.

However it could absolutely be the VANOS wiring, although the wiring in this car is in good shape overall. I will update with results, I hate these fix my car threads that end up ghosting without any results. I searched this issue for a good half hour through threads like that.

 

[chrisdfv]

I don't think it'll be anything to do with the crankshaft sensor, my understanding is that that is a critical sensor needed for the engine to run.

However it could absolutely be the VANOS wiring, although the wiring in this car is in good shape overall. I will update with results, I hate these fix my car threads that end up ghosting without any results. I searched this issue for a good half hour through threads like that.

Did you ever find resolution to your issue?