tach off by a few hundred rpm + mild hesitation on warmup

[Insidious Surmiser]

I havn't had too much time to tear the car down and check all of my connections/grounds... also still re-building my tool collection. But, I thought I'd see if anyone had any advice on what could be the cause. I plan on checking my TPS and ignition system first.

The car seems to hesitate a bit or stumble at low throttle input when it's cold (warming up) but once it's warm, it seems fine. But still... it seems like there is a lack of power, although the car runs VERY strong when it's actually making max output. I'm a bit confused TBH

also... currently throwing no codes

 

[stew_7mgte]

Stumble sounds like a afr issue. Not sure about the tach being off.

 

[Insidious Surmiser]

yeah, it's just odd altogether... if the o2 sensor was screwed it should be throwing a code, same goes for bad grounds, same for afm, tps. The car just feels like it hardly wants to go when it's cold... we'll see

 

[IndigoMKII]

yeah, it's just odd altogether... if the o2 sensor was screwed it should be throwing a code, same goes for bad grounds, same for afm, tps. The car just feels like it hardly wants to go when it's cold... we'll see

I do believe that's during closed loop operation, so the o2 input is null and void(Correct me if I'm wrong).

It sounds like your afr's are a bit rich under warm up, do you have a wideband? Have you checked your static timing after it's warm?

I know that when my car was close to 6 degrees static timing, my car ran like SHIT til it was warm.

 

[Insidious Surmiser]

yeah I'll have to do that for sure... sadly I do not have a wideband.... I did on my last car, and it would run 14.7:1 ALWAYS (except WOT) of course everything on my last car had been gone over with a fine toothed comb, multiple times (by me) but I haven't had the time or tools to do hardly anything with this car

 

[Insidious Surmiser]

still not shedding light on the tach issue... I've read of people having a loose/bad connection somewhere between the igniter and the ecu (one guy said he had to jiggle/mess with a connector near the ecu under the dash...)

I'll be putting a different cluster in the car too to see if that will fix it (waiting on the last gauge to come in the mail from tubbie)

 

[Insidious Surmiser]

still need to get under the dash and fiddle around/replace my gauge cluster with the one without crinkled white faces :nono: but I did find my car had 0 ign timing advance... so adjusting that got rid of the hesitation...