4.8is Cranks over but engine won't start

[upallnight]

Originally Posted by X5Ghost

Ya but I didn't see that before going to town tearing up the key. I was too eager to get going on A fix. No worry, it's my mistake. I hope to somehow get the key fixed otherwise, it looks like $280 key with programming. Outch!

My OBD2 shows no codes, I don't have access to a better reader unless I get the car towed to the dealer which about another $250 including towing and dealer diagnosis. Trying to avoid that if I can and do some diagnosis in my driveway, otherwise this is going to be an expensive repair when all said and done. Sucks!

Each time the engine is shut off, some of the engine codes are reset. Engine misfire is one code that is reset when an engine is turn off. That's why people always say that shutting down the engine and restarting the car and the engine run beautifully. That's because after so many misfires, the engine will shut down an injector(s). Now with an injector turn off by the computer there's a noticeable misfire, but shutting down the engine will reset the misfire count so now the injector is working again. There may still be a misfire, but the misfire is imperceptible to us, but not to the computer.

A scanner that can read the history of trouble codes along with data as to what was happening with the engine and car threw up the code is invaluable it determing what is the problem and the final solution. Everything else is just a wild ass guess. The days of the "Shade Tree Mechanics" are limited.

[crystalworks]

Originally Posted by X5Ghost

Ya but I didn't see that before going to town tearing up the key. I was too eager to get going on A fix. No worry, it's my mistake. I hope to somehow get the key fixed otherwise, it looks like $280 key with programming. Outch!

My OBD2 shows no codes, I don't have access to a better reader unless I get the car towed to the dealer which about another $250 including towing and dealer diagnosis. Trying to avoid that if I can and do some diagnosis in my driveway, otherwise this is going to be an expensive repair when all said and done. Sucks!

I hear you. That key should still be fixable unless you damaged it during the opening process. I've opened many of them and put them back together after soldering in new batteries. Hope you can get it fixed. I think I paid $190 for a new key from the dealer here in SA (previous X only came with 1 key). Maybe try another dealer. Sorry about that...

As for the codes... yeah a generic OBD2 reader isn't going to get you far. Bluetooth (or USB) OBD2 dongles are ridiculously cheap and can be used with Torque or other programs. That's an option. I use Carly BMW which, with cable & software, was about $70. I use it on my tablet and have good results with it.

[jfoj]

You can watch the tach and see if there is output from the crank sensor.

You should see the tach pretty steady at 100-150 RPM while cranking.

We have been seeing BAD KEYS that will allow the engine to crank, but not start. The EWS usually inhibits the fuel pump, injectors and starter, but for some reason we have seen cases that are crank, no start that are key related.

As for a replacement keyfob, for around $135, a Valet or Plastic Emergancy key if available are about $50 online if you READ this thread -

what did you pay for your E46 diamond key replacement? - E46Fanatics


The other simple tool to use for no starts is a can of starting fluid. A solid 2 second burst in the intake preferably at the MAF opening and crank the engine. If it starts and dies, you have a fuel problem. Either no fuel pressure, contaminated fuel or injectors not triggering.

Cutting open a key is the LAST thing you want to do.

[SchnellEuro]

Another thing to check is the Integrated Supply Module (IVM). They fail and are often overlooked as the cause, as they tend not to throw any codes.

[X5Ghost]

Originally Posted by upallnight

When the engine is cranking does the tach bounce a little? If there's a little bounce the CPS may be okay. This is not a definitive test, it just a cheap ass check to see if the DME is getting a signal.

No bounce or any movement of the tach what's so ever. Guess could be CPS?

Originally Posted by jfoj

You can watch the tach and see if there is output from the crank sensor.

You should see the tach pretty steady at 100-150 RPM while cranking.

We have.......

Cutting open a key is the LAST thing you want to do.

No needle bounce what so ever, completely dead.

Ya, l was following the suggestion of a fellow X'fer who had a reasonable suggestion at the time. I should have waited to vet this out further.

Originally Posted by Joshdub

Fwiw a Bluetooth obd dongle that'll work with the torque app is ~$10

If you have any suggestion of names and brands, I'll buy one to work with the torque app. Thx

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I have not done much for the last couple of days, been down with bad flu but hope to get back on my feet soon to tackle the beast.

[upallnight]

Originally Posted by X5Ghost

Thank you, I'm located in Minneapolis, MN.



No bounce or any movement of the tach what's so ever. Guess could be CPS?



No needle bounce what so ever, completely dead.

Ya, l was following the suggestion of a fellow X'fer who had a reasonable suggestion at the time. I should have waited to vet this out further.



If you have any suggestion of names and brands, I'll buy one to work with the torque app. Thx

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I have not done much for the last couple of days, been down with bad flu but hope to get back on my feet soon to tackle the beast.

If you order this from Amazon, you'll probably get it in a couple of days. The cheaper ones are usually from China and it may take 4-6 weeks to arrive here.

Amazon.com: Foseal Car OBD2 OBD 2 OBDII Bluetooth Diagnostic Scan Tool Check Engine Light for Android & Windows System Torque Pro: Automotive

[jfoj]

If the tach is not moving, then most likely a crank sensor which will cause the fuel pump not to run beyond the prime function and the injectors and coils will not trigger/fire.

This is a video the tach on a E46 330 cranking for reference - https://www.dropbox.com/s/k7tmin8qek...4_056.mp4?dl=0

As for an OBDII App, HIGHLY suggest OBDFusion, its cheaper than Torque and properly supports Wideband O2 sensors.

[X5Ghost]

Quick update after finally getting back on my feet.
Checked the spark and turns out there no spark produced. Bought a crankshaft position sensor and replaced it but still crank and no start.

So far, fuel pump and delivery ok, air is not restricted and ok, but no spark and CPS is not it. No codes. What do you suggest to look at next? This is puzzling.

[X53Jay4.8is]

Originally Posted by X5Ghost

Quick update after finally getting back on my feet.
Checked the spark and turns out there no spark produced. Bought a crankshaft position sensor and replaced it but still crank and no start.

So far, fuel pump and delivery ok, air is not restricted and ok, but no spark and CPS is not it. No codes. What do you suggest to look at next? This is puzzling.

I think at this point I might get the vehicle properly scanned to see what direction or path to go down next.

[X53Jay4.8is]

Originally Posted by X5Ghost

Ok, based on earlier suggestion, I took the key apart to check the battery which was soldered in and a PITA to remove but this didn't turn out to be the issue. If it was that, the engine shouldn't crank. Now the key buttons are inoperable so I will need to replace the damn key.
I checked the fuel line during a crank and there is plenty of fuel flow. Not a fuel pump issue.
Next need to check the crank sensor, I think that might be the issue.

What's the way to check the operation of the crank sensor? Is it to check for spark with the ign coil out or is there a better way?

Why did you take the key apart when the car was obviously cranking?