surging rpm Options

[Joe_1985]

well i just noticed this tonight, after i drove my 25 mile drive home and parked in my driveway, I noticed that my rpm would float between 1000 and 700 very slowly.

so i got out and stood behind my car and listed to the exaust (its stock) and id hear the rpms slowly go down to about 700ish rpm , sputtering missfire, then jump back up to 1000ish, sit for a second or 2 then slowly fall sputtering missfire, then repeat.


when i got the car i changed the cap, plugs, wires, rotor button, cleaned out the intake manifold, and throttle body.

ill check the plugs in the morning.

it also surges up and down the rpm range if i hold the gas steady, does the same thing falls very slowly then goes back up.

btw this is a 7afe with 189,000 miles on it

[Mstoochn]

why is your timing advanced.... 7a-fe shouldn't be adjusted

[Joe_1985]

why is your timing advanced.... 7a-fe shouldn't be adjusted

why did you post a reply, your reply was neither helpful or useful

to everyone else, thank you

[Mstoochn]

why is your timing advanced.... 7a-fe shouldn't be adjusted

why did you post a reply, your reply was neither helpful or useful

to everyone else, thank you

A/F is going to be off if your firing is advanced beyond Zero degrees, without the proper A/F ratio to begin with of course your going to be running lean, also causing lean missfires when there is too little fuel in the mix that relate to what is known as floating rpm. if the ecu is similar to the 5s, the ecu controls timing (aside from cam gears, or the cams being set wrong to begin with)

look at your fuel system as well. Filter is most probable

if your EGR was a miss your car would smell HORRIBLE, almost intoxicating.

Fuel economy bad?

This post has been edited by Mstoochn: Nov 7, 2009 - 6:05 PM