Engine stumbles on cold start, restarting causes it to run normal

Spunbearing · #1 07-25-2016, 01:26 AM

Hi guys,

When I start my 2001 X5 3.0 with 206K miles on it cold, the engine stumbles like it has a bad ignition plug. If I turn it off and then restart it the problem goes away. The last code it threw was P1347 - Misfire on cylinder 3 with fuel cutoff. I have read a bunch of posts on this issue and I have had to replace a coil before (cylinder 1). When that happened I moved the coil around and OBD code change to reflect the move of the bad coil. Restarting the X5 never "fixed" the issue, it always continued to run ruff. Several posts I read talked about VANOS timing being changed on startup and that the VANOS unit needed to be serviced to fix the issue. It is the running well after restart that is really tripping me up.

I don't mind replacing the ignition coil but I just don't want to throw parts at it. Right now it looks like that is the best place to start. If anyone has any different opinions I would love to hear them.

As always, thank you guys for all your help.

Spunbearing

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upallnight · #2 07-25-2016, 07:23 AM

If moving the coil changes the location of the cylinder that is misfiring, you have a bad coil. Just change the coil.

Why does the great communist state of Illinois list your X as a Station Wagon? The shitty city of Shitcago list my X as an oversized vehicle and I need to pay extra for the Shitty vehicle sticker each year.

Spunbearing · #3 07-25-2016, 11:45 AM

I will try moving the coil but the part that really confuses me is that it seems fine AFTER restarting it.

I have no idea why it is a station wagon according to Illinois. Probably because they are so behind the times they don't have an SAV category!

upallnight · #4 07-25-2016, 01:31 PM

A computer will count the number of misfires in each cylinder and if the number of misfires exceeds the parameter programed into the computer it will shut down the injector and throw up a SES or CEL light. Shutting off the engine and restarting the engine will just reset the misfire counter.

Spunbearing · #5 08-08-2016, 03:37 PM

Ok, time to update this post. I have been side tracked with work and having my hood latch break so I had to waste a couple of hours going through the grill to get it open again. Now that adventure is over.....

I picked up a new coil and boot for testing and this did not fix the problem, I am still seeing the same code.

I picked up the BMW 1.4 Scanner and got the following screen shots The first one is before I cleared all the errors and the second one is of the ones that came back. There is a code for a crankshaft sensor in the before screenshot but I am not sure how long these codes are stored from Is it 50 starts like the ODBII codes? I am thinking this is the problem.

I also pressure tested my fuel pump and it look like I am getting a solid 44-45psi when the car is off and about 50psi when it is running.

Please let me know what you guys think.

upallnight · #6 08-08-2016, 04:15 PM

Looks like you have a vacuum leak. The 02 sensor are reporting a lean condition. A lean condition is interpreted as a misfire by the computer because a lean cylinder doesn't produce as much power as a normal or rich cylinder. Do you have an OBD 2 scanner that can perform live data? You need to look at the short term and long term fuel trims. Most likely I would look at the rubber boot that connects the MAF with the throttle body and the IAC valve for cracks and as the source for a vacuum leak.

Looks like your AUX fan is also bad. Does the AC work in stop and go traffic?

Spunbearing · #7 08-09-2016, 09:33 PM

Thanks for the reply upallnight. I am not disagreeing that it is a vacuum leak but I think it is something electronic or electronically controlled. If it was just a vacuum leak restarting the car should not have any effect on it, right? My previous experience with vacuum leaks said the issues would still be there.

Also, because you have a Lotus and are kind enough to reply to my posts I doubled checked the intake boots again. The inner one did have some surface cracks on the tube that goes to the ICV so I replaced it. The cracks were not all the way through and passed my water test but why tempt fate. There has been no change in the running condition of the car after changing this, I still have the issue.

After thinking about it for sometime I was wondering if the issues might have something to do with the SAS system. That is suppose to run on cold starts, perhaps there is something wrong with the system allowing air into the intake. Any opinion on this?

There was a post on an e46 forum where this issue turned out to be a cracked exhaust valve. I don't think it is anything that extreme with me because the issue goes away with a restart.

I do need a new Aux fan, that is next on the list. The cheapest one I could find was a Hella from Turner for $300. That is a lot of money for just that fan!

upallnight · #8 08-09-2016, 10:32 PM

If you are anywhere near the South Loop / Chinatown area, I can hook up my OBD II scanner and we can look at the fuel trim to determine if you have a lean condition.

upallnight · #9 08-10-2016, 09:55 AM

You could have a stuck Idle Air Control valve.

That could also be the source of your misfire and lean code at start up.

Here's a video on testing and cleaning it.

https://www.youtube.com/watch?v=3KPkslbjfJg

Spunbearing · #10 08-11-2016, 12:13 PM

Thanks for the offer upallnight, I shot you a PM. This is very kind of you.

So I went through the SAP system yesterday morning to make sure it was not leaking and everything appears to be working fine with that but I noticed I was hearing a vacuum noise coming from the DSA valve. After some investigating I noticed that one of the tabs on the diaphragm housing was broken off and by pressing on the housing I could hear the DSA valve actuate and the vacuum go away. I was very excited, thinking that I had found the cause of my vacuum leak and replaced the valve with a new one but the problem still persists. The engine still runs ruff on cold start up until you turn the car off and then back on again. Does anyone know what changes on a cold startup? Also, what vacuum lines are by the intake for cylinder 3? I am thinking it would be something close by to cause the issue on only one cylinder.

My biggest fear is that it is a lifter or the head gasket is bad.

I have had an ICV go bad on this car before and when that happened the engine would not keep running and the dash lit up like a Christmas tree. That happened around 80k miles. I have a 330 i could steal the ICV out of and swap in there plus another one on a used engine sitting in the garage I could try. i am getting to the point where I think I might have to take the intake manifold off. I also just replaced the "big" 7mm rubber cap on the back of the intake manifold because the previous one was shot.

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