yay hesitation bucking at low rpms~RESOLVED~

[kevin derhouson]

Just did a timing belt job, kevlar belt, pulleys water pump tensioner seals, fluidampr (used longer arp bolts ofc) install whole shibang..

now i'm 100% certain that everything... everything.. lines up absolutely perfectly.. while it was being done i left the key in the accessory position and drained the battery.. put a slow charge on it, fired up idles normally(so ISC should be fine) whole deal.

driving at low rps mostly happens in second gear i get sporadic hesitation and some bucking.. don't say MAS because i run SD :p
sometimes wants to die when down shifting for a light.

high rpm everythings great.. builds boost normally, runs normally, powers there..

plugs fine
wires fine
fpr fine
CAS checked..
fuel pump fine
vacuum is normal.. boost leaks checked.
FML

edit: suppose i didnt' check fuel filter but the timing pardon the pun of it seems suspicious.

[Marke Bailey]

you could have meth leaking into the charge system, making large droplets that dont burn.

[kevin derhouson]

will check, thank you marke

edit: that would surprise me though, i got a warning light on my hsf-3 when one of my fittings was leaking slightly.

[Brett Haviland]

is it possible that the tuning system, PCM or SAFC (if you even have one) lost its tune or something when the battery went dead


good job on tackling all that work on your own tho  that job can mess  people up  a lot of the time.

[kevin derhouson]

don't think thats possible as i run ecmlink v3, and watching my afr's they seem normal under all conditions..

has to be spark or fuel imo.. i'll figure it out :p

just frustrating.

[KevinBuckham]

Did you switch to SD at the same time?

I had issues up to two weeks ago with my ECMLink V3 speed density tune related to idle control and issues at ~2500 RPM in second gear at low / mid throttle.  Finally have it all cleaned up.  My idle issues were fixed my adjusting O2 Feedback adjustment rate.  Also had to do some small increases to tip-in related to TPS change, up my idle and low throttle/rpm timing, and slightly increased coolant temp based fuel compensation.  Now it won't die while coasting to a stop even if I immediately kick on the heater fan and A/C.  Also drive-ability from cold is much improved.

For your idle trouble, do you notice the A:F going lean just as it dies?  How long is your lead to your MAP sensor from the intake manifold.  Keep it short (6" or less) and definitely don't have anything else on that line.  Are you running a 2G cam sensor, or a 1G style?  Have you verified base timing if 1G style?  If you are on a 2G style, do you have a 2.4?  If so, they tend to like a bit (not lots) more timing at idle especially if you have upgraded cams.

[kevin derhouson]

nah been running SD for over a year now


resolved:

after driving more and being astute i realized that the misfires/stalling were happening only in

2/4/R gears

1/3/5 gears were not effected..

turns out a wire from the main relay wandered a bit and was grounding out.

[kevin derhouson]

Did you switch to SD at the same time?

I had issues up to two weeks ago with my ECMLink V3 speed density tune related to idle control and issues at ~2500 RPM in second gear at low / mid throttle.  Finally have it all cleaned up.  My idle issues were fixed my adjusting O2 Feedback adjustment rate.  Also had to do some small increases to tip-in related to TPS change, up my idle and low throttle/rpm timing, and slightly increased coolant temp based fuel compensation.  Now it won't die while coasting to a stop even if I immediately kick on the heater fan and A/C.  Also drive-ability from cold is much improved.

For your idle trouble, do you notice the A:F going lean just as it dies?  How long is your lead to your MAP sensor from the intake manifold.  Keep it short (6" or less) and definitely don't have anything else on that line.  Are you running a 2G cam sensor, or a 1G style?  Have you verified base timing if 1G style?  If you are on a 2G style, do you have a 2.4?  If so, they tend to like a bit (not lots) more timing at idle especially if you have upgraded cams.

to be honest i had RG set up my ecmlink/SD because i'm a pussy :p

[Chad Giffen]

nice catch

[John Hartman]

definately a good find.  You gots dah skillz yo!

That sorta shit can drag you down for a long period of time.