Suspicious sporadic start
 

Hello guys. I'm new here and this is my first post. I just bought a 2003 4.6is. And it needed a little work, according to the seller. He stated that all it needs is a throttle body and maf sensor. I scanned the vehicle with my INSTA software, and sure nuff, it came back with the codes for the throttle and maf sensor and also the pedal potentiometer. I changed the tb and sensor but couldn't get it to start. Mind you, last week, it was the samething. I tried starting it bit it wouldn't start. Went out a few days later, it started right up. Along with the bad idle he told me about. I let it idle for a while to see if it would clear up but it didn't. Turned it off and I couldn't start it again. Fast forward to now, this is where I'm at. Cranks but no start with the TB and sensor newly installed. I checked for fuel in the rails, has fuel. Checked for spark. No spark
I don't know why it would start one time and not the next. Is it possible that it being immobilized? I don't know at this point. Can I get some of yous to help? I would really appreciate it. Thanks. And I have videos of it idling and pictures of the codes I pulled if that would help ya.

Crank fuel no spark hints at EWS so scan for EWS.

No start intermittent suggests crank position sensor. (and may also inhibit spark).

Can you clarify what EWS is? And with CPS? It never showed up on the scan. Could it still be a possible culprit? And which CPS should I change or check? There's two of them.

CPS is cam position sensor and I'm not sure that will prevent a start, the car I think has a workaround for the CPS not working.

Crank sensor is CPK for some reason. I'm pretty sure the car won't allow spark until it knows where the crank is.

EWS stands for D rive A way P rotection.

(Whatever the three words in German). Aka immobilizer.

The "catch22" is that you won't get a code until you get a start from my understanding. But look into immobilizer, because it comes up on the forum regularly the EWS gets out of sync and allows crank but no start (why allows crank the world may never know)

Okay. Will do.

Can we check fuel pressure? How many miles on it? How much fuel is in the tank?
No spark is a biggie. Remove and clean the cam position sensors. Check the wiring harness. Wiggle the harness while someone cranks it.

Which is the cam sensor and which is the crank sensor?

Yes there's fuel in the tank. I have 15X,XXX miles on it. I just replaced the tb and maf sensor.

Cam sensors are right on the front of the engine. The crank sensor is usually near the bell housing for the transmission. I've never changed on M62 not sure exactly where it is.

Okay.

I can monitor cam sensor realtime with my scanner. I don't know if I can with the crank sensor but that would be very helpful.

Do you use INPA or INSTA as a means to do that?

I use a foxwell nt-510 scanner. But the laptop solution has much more I don't have so I don't know where to.search.


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EWS = Elektronische WegfahrSperre

If the rolling code sync between EWS and DME is lost it's lost permanently until initialised again with diagnostics. This can't explain temporary non start symptoms (cranks but won't allow fuel injection).

(If we were talking about temporary symptoms where the engine is not even cranking a problem on EWS module key recognition and start motor activation is a different thing.)

EWS 3.3 bedtime reading.
http://www.e38.org/EWS.pdf

Solid point on the sync. Can't be ews sync but can be a bad key or a bad key antenna.

Do you have alternative keys to try?

Like I said earlier if there was a problem on EWS key recognition the engine would not even crank as starter activation would not be allowed.

I got it to start. And it idled for about 3 min and it died. I could not get it to start again. But when it did idle, it was idling rough. Before this, it gave me an error code for the throttle potentiometer 1 and 2 and one with no number next to it. Codes, 000075, 000076, 000077. One for the pedal travel sensor, potentiometer 2 (0000E8]. And 000073 - hot-film air mass flow sensor. Learn function, lower stop, throttle actuator (000086). I wanted to up load the pictures so that you can see what I see. But having an issue doing that. Hopefully this helps.

That's a boat load of errors most having to do with throttle.

If you can bring up realtime values, check on the gas pedal signal (both) and the throttle position (both). If the car can't read the tps I'm sure it will just pull the plug on running.

What's going on with the Alternator? If you can't get a stable voltage it can cause similar symptoms.

Feels like there's wiring loom damage check on the wiring from the TB that joins up and goes to the DME. Often when you get lots of different systems having errors it's a wiring problem.

I always thought that's how it should work but I hear tales of people trying to start with ews sync problems and say it cranks.

When I recently bought two new keys, I tried the valet key and it did nothing the first try. Second try it started the car. I would expect of any ews problem no crank at all but I hear of cases where it cranks but no start.

I also must say this. I didn't mention it earlier because I didn't think it would matter or make a difference. All the while I'm doing this, I'm jumping it with my truck because the battery that's in it has a bad cell. So it's just a bad battery.

BMW are very sensitive to voltage. A jump start is a one off to fix a battery run flat from leaving power on. You need to have a functional battery.

For testing purposes you could probably disconnect the dead battery and run off a host battery from a near car but don't try to leave a battery with a dead cell attached.

Okay. That's good to know. Didn't know that. So do you think that would make all tr h difference? What about the rough idling? After changing the throttle body and maf sensor? Wouldn't you think it would idle better or correct it for that matter?

Jumpstarting a BMW in general is a pretty bad idea.

And yes, 100% you can royally screw up synchronization of your various modules with a bad battery and low voltage.

I had this same problem with an old e39 I was trying to bring back to life. Car started and I drove it home. Battery was bad, didn't want to replace it, and went to start it - CLICK. Died never would start again because the EWS lost sync. And it fried my Transmission control unit.

Spent WEEKS hunting through INPA to figure out how to resynch the codes and get it to start, and was fortunate an e39 TCU isn't coded to the car.

A painful lesson. Get a good battery before trying to diagnose other (esp electrical) problems.

Also +1 on a real scanner OR a machine with INPA. I use a Launch X431 mini

Wow! Had no idea. BMW'S are very finicky, I find. Will do that.

I'll post back afterwards. Oh! So in doing all this troubleshooting and long starts, how would I keep the battery from going dead?

looks like you're in good hands with Andrew here but just second what these guys have said these modules are so voltage sensitive, I would invest in a decent multi stage charger and keep that connected for these things also if you are ever connected to ista/programming keep it hooked to a charger.

Not sure if it has been suggested and might not be related because you are getting intermittent start but no fire but continuous crank could be a DEM/EWS misalignment. You mention you already have ISTA so maybe worth giving that a try, there are plenty of vids on youtube to show you how to carry out a DME EWS alignment with ISTA

I appreciate that. And inhale been going back forth between here and YouTube, plus other member boards to get this solved. I will definitely keep posting my progress.

So maybe, once I install the new pedal, it will correct the rough idle. You think so?

You need to be able to read data real-time like the pedal and throttle positions.

When my idle was horrible it was from a giant vacuum leak. Car set a code for ICV.

When wife's car acted similarly, it ingested the o-ring from the MAF into the throttle body and jammed the throttle plate.

I would love to do that. But my version of INPA is older, so therefore don't have option for e53. Maybe I could use the e38 option since it's the same engine. But, also, when I press the pedal, it doesn't respond or anything.

I bought a foxwell scanner for working on my e53. It's really never let me down. Always gets to the module I need.


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Did it have the no start problem before you did the work? When it has started was it only when the engine was 'cold'. When it starts will engine rev normally?

I wouldn't do anything until I replaced the battery. You're going to need one anyway. I wouldn't replace anything or take anything apart. After installing new battery I would clear the codes and see what comes back when it starts the next time.

Well the guy I bought it from said that it idles but when you press the gas pedal, it wouldn't respond. So when I got it home, it didn't start either. It wasn't until the next day that it started up and it idled rough, like he stated. But going to put new battery in along with the new pedal and see what happens.

Did I miss what you are using for scanner?


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I'm using INPA and ISTA.

Ok those will show everything you'd want.

Ok

I wish I can share the display of the screen here.

You can do a screen shot or else people take pic with their phone


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I tried that. It's too big of a file to upload.

I use tapatalk app to auto resize


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Thanks for getting me hip to this. [emoji1]
Here are the pics.https://uploads.tapatalk-cdn.com/202...c64ee5115a.jpghttps://uploads.tapatalk-cdn.com/202...e984bf0f47.jpghttps://uploads.tapatalk-cdn.com/202...d353b4ad80.jpg

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I had the same issue with my throttle body at one point. Try this...disconnect the Throttle Body connector. Clear the codes from your rig...and fire it up. It should start using a default algorithm so the response won't be quite as good. If it does start up and run well (as compared to what it's doing), reconnect the TB connector with it running. Shut the car off and re-start. Totally resolved my issues. For some reason, the TPS communication with the DME didn't "refresh" appropriately until I did this procedure. Then I was off to the races with full throttle and nice smooth idle.

Did you replace the MAF and the throttle body or just the throttle body?

What do you mean by won't respond- it shows no indication it is trying to rev up? Or, if you depress the gas pedal it starts missing or roars but doesn't tach up and then stalls shortly after?

Codes are not always definitive. Sometimes they are more directional. I wold be sure the MAF is operating properly. In your case some of the codes could be problems that the MAF is causing.