Should I do a computer reset?

[KenB]

Should the battery be disconnected to reset the engine management computer as a matter of course when putting in new spark plugs and/or ignition components?

I went to replace my spark plugs a couple weeks ago after 40k or so miles...

3 spark plug wells were filled with oil so I replaced the valve cover gasket first, cleaned out as much oil as I could before removing sparkplugs, (some oil still went into cylinders as it smoked like a bitch after starting) and replaced 3 spark plug connector boots that had been soaked in oil for I don't know how long. I also replaced the air filter. Coils were all replaced before the last set of plugs. Old plugs were Bosch, new ones NGK.

Instead of getting better gas mileage, it was worse. The engine also seemed to run a little rough and sluggish intermittantly. Sort of like a coil was weak or a plug not firing 100%

ON my daily commute, I drive 70 miles each way, 50 miles at 80 mph. I kept a close watch on my gas consumption via OBC. Right after changing everything I got around 21.5 mpg at 80mph. (cruise control on).

Gradually over the last 2 weeks (1,500 miles) it has improved, yesterday I got 24.5 mpg and the roughness and sluggishness is all but gone.

Should I have reset the computer? Has it been trying to re-adapt to the new parts from where ever it was with the old plugs? They were pretty badly gapped but clean.

Should I still reset the computer and start fresh? Or let it go since it seems to have improved.

Any opinions, speculations or advice welcome.

Thanks.

[632 Regal]

concidering that you cant really hurt anything I wouldnt hesitate in resetting it.

[BuckNaked]

um, okay , silly question...
how do I reset my OBC and what all gets reset?
A fresh start seems in order.

[632 Regal]

lol... there are 2 ways of rebotting the computer. 1st is you gan remove the batt cables, connect them together and turn the key to the run position for 15-20 minutes, this will drain the capacitors and you will need to re-enter the radio code. The 2nd way you just purr the bulkhead connector on the DME for 5-10 minutes, plug it back in and your good to go.


um, okay , silly question...
how do I reset my OBC and what all gets reset?
A fresh start seems in order.

[632 Regal]

or search "reboot"

[ryan roopnarine]

if you reboot it now, you will be back to square 1, back to bad gas mileage and rough running.

[632 Regal]

it's like a magic pill on my car.
if you reboot it now, you will be back to square 1, back to bad gas mileage and rough running.

[Morgenster]

When I had my alternator swapped I think my mechanic did the same.
By the time I left the shop my idle was like never before, but it got back to where it is now (louqy) pretty fast.
I'm wondering if doing it again is in order and also why after a reboot all goes well and then gradually gets worse again.
I'd assume the problem with my idle to be electrical and not mechanical.

[KenB]

Thanks for the replies, I'm due for inspection next month. If it fails for emissions I'll put the stock chip back in and reboot to get it through. Last time it was just over on one of the parameters but it was right before I put new sparkplugs in 2 years ago.

For now, I'll leave it since it is running great finally, I should have done a reboot when I first changed everything.

When I've rebooted in the past (last time 6 months ago with the new battery) I never had as poor performance as I had with this "tune-up" it just took a little while to reach optimum performance.

Right now it's back to it's normal smooth self, so I think I'll leave it be. My average combined mpg is 23.5 so I think it's about as good as it's going to get.

[BillionPa]

if your idle goes downhill after running like a dream, your O2 sensor or MAF sensor needs replacing.

[eem2x]

One think to keep in mind... my idle issues (M60) resulted from the computer doing it's job properly based upon the inputs it was receiving from the O2 and the MAF. Garbage in - garbage out.

My first inclination was that THEY were the problem but ultimately it was from the intake manifold gasket. I found when working with a rough idle investigate the parts that are core 'blocking and tackling' of the sytem: vacuum leak in the intake manifold gasket or valve cover gasket, the e34's version of the PCV, which is the oil separator and the corresponding backplate, the throttle control valve (easy to remove and blast with solvent), the oil cap and dispstick leaking air. Once these are verified then it could be the O2 or mass air flow sensor, but with no moving parts they'd be last on my list. Good luck!