so all at once yesterday when i was driving home from work i went to stop at a light and the car died. started it back up and my idle was really rough and it would barely run. it seems to drive like normal and just have problems idling. at idle it sounds like a ported engine with a brap brap brap kind of idle. anyone have any ideas why this might happen randomly? i dont think its a problem with the ecu or any sensors because the megasquirt seems to be working like normal.

setup:

s5 T2 shortblock 280 miles on rebuild
FD intake manifold
MS3x ECU
VMIC
Walbro 255

 

vac leak?

 

chugging is from too much fuel so it wouldn't be a vacuum leak but possibly a failing or stuck AFM.

 

I thought it was a vac leak too. But too much fuel makes more sense.

 

smell the exhaust - does it stink like gas?

 

it might be a vac leak, i checked yesterday for them and couldnt find a source to the problem. im going to buy a propane torch today to do some further testing.

AFR at idle is 13.1. ive tried making it more rich and lean and neither has an effect on the idle (as far as getting rid of the lope)

I have no afm as im running a megasquirt standalone.

thanks for the tips so far guys.

 

well i tried finding vacuum leaks with a propane torch and either couldn't find any, or it didnt really work.

heres a couple videos that help describe the problem.

Start and idle before problem occured
<iframe width="420" height="315" src="http://www.youtube.com/embed/HmZIfLop6no" frameborder="0" allowfullscreen></iframe>

heres a vid at idle and another driving around
<iframe width="420" height="315" src="http://www.youtube.com/embed/r0-fdtIdKNE" frameborder="0" allowfullscreen></iframe>

<iframe width="420" height="315" src="http://www.youtube.com/embed/ixJmUvlTcc4" frameborder="0" allowfullscreen></iframe>

 

Does it smoke consistently? What color is it?

 

Timing? I'm just throwing it out there... how do the plugs look?

 

the smoke appears to be oil to me. could be from a slightly heavy premix or a still breaking in engine.

i have checked timing but i will do so again just to double check.

 

sounds like your timing is jacked, the squeaking noise sounds very much like preignition.

 

What would this mean? Too much fuel? When I start my car in the morning it smells like gas every time. It reminds me when I used to own snowmobiles, aha.

 

what should my timing at idle be?

 

well i think somehow i have a fucked up apex seal.

 

Compression numbers?

 

I'm a little late but I'd do a compression test before wasting time on anything else. I've always hated when I hear that idle sound.

 

ima compression test it today. if its anything but perfects ill have it out and torn down tonight. but when i pull the trailing plug on the rear rotor i get a loud whoosh followed by two slightly quieter whooshes. which makes me think apex seal. i found that i was setting up my timing wrong and that it was actually 10 degress advanced from where it should have been.