Beretta.net

i asked this before and didnt really have enough info to give you guys for any feedback.

now i think i have it narrowed down to figure out what is causing the sputtering and shaking at stoplights.

1)only happens at stoplights or signs in gear with my foot on the brake
2)only does it when gas is low AND right after i put more than half a tank in
3)goes away after a little driving
4)doesnt matter what kind of gas
5)fuel filter, air filter, plugs all have been changed(had a full tune up not too long ago
6)never has cut off
7)oil pressure gauge and rpm's drop(hovers normally at 7; drops to around 5)

not sure if this is related or not....
8)noticed a slightly noisier idle

1994 base with 3100 auto
113,XXX miles

does your car have a tach? (not that they are deadly accurate i hear), but what rpms are you spinning when in gear at a stop light? could just need an idle relearn. i think my '95 3100 settles around 700-800 rpms(not lower than 600 for sure) while sitting at a stop light, when warmed up

you didnt mention plug wires. plugs gaped decently close?

berettaboi wrote:does your car have a tach? (not that they are deadly accurate i hear), but what rpms are you spinning when in gear at a stop light? could just need an idle relearn. i think my '95 3100 settles around 700-800 rpms(not lower than 600 for sure) while sitting at a stop light, when warmed up

you didnt mention plug wires. plugs gaped decently close?

the tach settles like yours at around 700. when it sputters it drops to around 550-500(guesstimate)

how do you do an idle relearn? why would i need to do one? does something go belly up that would cause the idle to be off?

when i had the tune up done the wires and plugs were included in the service. what should i be looking for when checking the plug gap?

yes an idle relearn is just unhooking your battery for 5 mins+, and then hooking back up and restarting the car... i like to turn on nearly all accessories to put full load on the alternator, then the ECM can learn it's lowest possible idle with a full load. you should leave the car at idle, until the fan comes on (even that is beyond operating temperature) and then you can shut the car off, and should be good.

i forget what the gap for the 3100 spark plugs should be (should be in a post around here somewhere, or on autozone's website, or other). it's not a huge deal if it's only a bit off... many people just throw them right in without gaping the plugs, but for best results in performance and gas mileage they are meant to be gaped specifically for each different application/engine. there is a 'keychain' gauge tool for gaping the plugs, no more than $2-3 at many parts stores

could be even moisture getting involved. it's a good idea to use di-electric grease on the spark plug wires for both ends to prevent that.