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DISCUSSION => Engine management => Topic started by: 91 318i on April 17, 2013, 11:18:20 PM

Title: Hesitation/surging problem
Post by: 91 318i on April 17, 2013, 11:18:20 PM

Recently got my car running again. Ran great for about 5 days. Not a single issue.

It happens at any rpm and any gear. Mostly in first and second. Lacks power and feels like a bad miss on one or two cylinders.

Today I swapped the throttle position sensor, cam sensor, crank sensor, and replaced both intake manifold gaskets. I bought a fuel filter that I plan on putting in tomorrow. It looks really old and probably wouldn't hurt to change anyways. I've cleaned the iac and afm as well. Cleaned the throttle body too. No change at all.

I tried unplugging the o2 sensor and still no change. When I unplug the afm however it runs for a few minutes with no problem then reverts to the hesitation issue again. Does this mean its the afm?

Please help
Thanks

Title: Hesitation/surging problem
Post by: 91 318i on April 18, 2013, 12:31:10 AM

Update!

I was at a friends house and on the way home it decided to misfire at any rpm and now in the driveway it has a really bad lopey idle. It drops down to a near stall then up to about 1000.

All 4 cylinders have spark. Fuel pressure regulator? Injector?

Title: Re: Hesitation/surging problem
Post by: colin86325 on April 18, 2013, 10:59:42 AM

Does your AFM harness have an extension lead on it? Basically just looks like another harness that attaches  onto the wire that comes from under the intake.  I was having some problems and I removed my extension and found it was full of water and corrosion.

Title: Hesitation/surging problem
Post by: 91 318i on April 18, 2013, 12:13:14 PM

I do have that extension on there. I took it off because I thought it was pointless. That's when the problem started. I have since put it back on

Title: Hesitation/surging problem
Post by: 91 318i on April 18, 2013, 07:28:47 PM

Today I swapped injectors between the current one and one of the set I had laying around. Changed the fuel filter. No improvement in how she runs. Verified spark on all 4 cylinders. Compression is 120+. Swapped in a different fuel pressure regulator. Messed with the afm some more but got it to a good spot as far as adjustments go. Runs just as bad or worse. Now it barely wants to idle. Has almost zero power. All 4 coils appear to be firing. Has code 1234 according to stomp test.

What does this mean??

Title: Re: Hesitation/surging problem
Post by: colin86325 on April 19, 2013, 09:33:23 AM

I'd suspect some kind of problem with the wiring to the AFM or with the AFM itself.

Title: Hesitation/surging problem
Post by: 91 318i on April 19, 2013, 10:54:38 AM

I've tried everything except swapping the afm because I don't have another one laying around

Title: Hesitation/surging problem
Post by: 91 318i on April 19, 2013, 07:23:22 PM

Update.....

I feel so dumb right now. Ended up being a hole in the number 3 spark plug wire.. Anyways. Got her fixed. Runnin like she should.