Misfiring, Popping, Dying - Problem?

[MNwe4]

Ok guys, here's my situation. Car was running great and now it popps and lays over when I accelerate with any boost, sometimes when decelerating, and dies sometimes at a stop or idle. Basically it's not driveable. I had a similar problem a while ago and it was a bad cam position sensor. What could it be now? Coil pack, ignition module, crank sensor, and cam sensor are all new and the car was FANTASTIC until last weekend. I've been reading stuff about the cam sensor and it seems fairly complicated as to how its set and affects performance of the car. Would it be possible that my car is chewing up cam sensors for some odd reason?

 

[forcefed3.8's]

When it won't idle, unplug the mass airflow sensor. If it clears up, the sensor is bad. Check the plug wires. Did you replace the cam sensor yourself, and how was it set? After the car is running the cam sensor can be unplugged. If the problems go away, something is wrong either with the setting or the sensor itself.

 

[bmackinnon]

yep, sounds like the maf has gone south.... try tapping on it while idling, and if the engine stumbles, that's a sure sign...

 

[MNwe4]

Thanks guys. The plugs and wires are new also. When I say stuff is new I mean within the last year and the car has only maybe 3,000 miles on it since the rebuild. I have the MAF sensor and translator from Full Throttle and I understand those are pretty robust. Plus a bad MAF wouldn't cause backfiring would it, just stumbling and hesitation? Had 3 bad MAFs in the past before the switch. The cam sensor was installed by a professional and the car ran GREAT for quite a while, just now started acting up. Can the cam sensor come loose and move, or is it something that has to be taken out, rotated, and put back in?

 

[turbojd]

Make sure the crank sensor is no loose and contacting the interrupter ring also. What brand coilpack and ignition module?

 

[bmackinnon]

Have you checked the fuel pressure? A failing fuel pump will also cause the symptoms you are experiencing.... :frown:

 

[MNwe4]

Fuel pressure is great. Not sure on the brand of coilpack and ignition module. Are there certain brands to avoid?

 

[86GN-862+2]

What do the error codes say? It is probably a loose connector/ground maybe?

 

[GNAT87]

Avoid anything but AC Delco

 

[MNwe4]

Have no idea what the error codes are. My main problem is that I'm in Minnesota but my car is still in Missouri where I used to live. So it will be going back to the performance shop to be fixed, but I like doing the research and trying to figure out possible solutions to help speed up the process, plus it's fun. I was just back in MO driving it when it started having problems, but as long as it's an easy fix and nothing else goes wrong, I'll be bringing it up here after Memorial weekend. Thanks for all the ideas guys, I like exploring all possible solutions.

 

[at7we2]

did you get this problem resolved yet?

 

[1chance]

did you get this problem resolved yet?

+1

 

[1chance]

How do you check coils with volt meter?

 

[turbojd]

How do you check coils with volt meter?

Check the towers front to back. 11-13 ohms.

 

[typetmkp]

I

 

[typetmkp]

I have the same issue have checked almost everything. fuel press good. cam sensor set. tps consistant. only thing that pops up funny on the scan is to o2's will give a very lean reading from time to time consistant with to pop. going to try a diff maf tomar.(did the tap test nothing,try'd a autozone maf didnt change.) Would a bad o2 cause this? or is something else telling the motor to go lean and the o2 is just reading it? any thoughts?

 

[89mulletbird]

O2 going lean could be bad O2 sensor, change it, it is cheap.

 

[chris_mile]

didnt see anyone mention timing chain. this is exactly what mine did when i first slipped a tooth then it eventually free spun. just a thought.

 

[at7we2]

forgive me if you guys already noticed, but this is a fairly old thread. the most recent post was April of '09 prior to 89mulletbird's post this morning. just thought I'd mention that in case someone didn't realize it.

 

[89mulletbird]

oops!