Some Data #'s for skip/surge issue.

[HighMileage]

Lately I have a light throttle/light load skip-surge issue going on.

I first noticed that the BLM Value #'s are around 115 in the 8th and 12th cell. (far right,counting across)

Hopefully these 400 frames of numbers can shed some light on this. Steady on the pedal,hold on,here we go on the bucking bull for 400 frames:

Speed: 32-34mph.
RPM: 1,575-1,625.

AFR: 14.8
MAF: 15.9
LV8: 50
TPS: .66v
Clt: 193'F.
IAC: Steady at 58.
Prog Idle: 650
MAP: .12KPA.
Int air: 84'F.
Ign v: 13.3 and steady.
02: Everywhere between .098 and .741 (new Denso 02).
Advance: Varied between 43-45.
Inj pw: 3.8-4.2.
Inj duty: 4.9-5.3%
EGR-0.

X-counts: Took 523 frames to go 0-255. The Delco I had in there went faster. But same skip/surge.

Status: Checked boxes: Closed Loop and BLM Learning.
3rd gear box checked. TCC box checked.

Block Learn Value box constantly changed +/- 10 from 128.


Once past the light throttle/light load "mode",it is nice and smooth. I hear light pops out of the exh while coasting down a hill.

But hit the gaz,and it goes!

Any ideas? Thanks.

Steve. '87 GN,t-tops. Mostly (all?) stock.

 

[TurboDave]

There's nothing much to be seen in the static data you provided in the post.

You need to upload the .dat file you recorded so we can look at it.

 

[HighMileage]

Alright,I think I'm onto something. In the last few days,I have been checking everything from vac leaks...to crank sensor..to running with the cam sensor unplugged,etc. Plus checking the numbers I have against all I've read. Nothing points to anything.

Today I reset the ECM. A 128 appeared in all of the cells. I went for a drive...

The skip/surge at light throttle was completely gone! Idle is smoother,too. It runs flawlessly. About 15mi later,I'm heading home. But,the issue *might* be coming back.

** One thing that was happening when I first bought this car,was the SES light would flash on/off quickly with a hard bump. The engine would quit/come back quickly.

Cause: It turned out the the ECM plug(orange wire) next to the battery was barely connected and not clicked.

Could it be that the bad connection damaged part of the ECM?

I *did* have a GM car whose batt conn was loose. The ECM failed soon after.

Any thoughts?

Steve. '87 GN,t-tops. Mostly (all?) stock,PowerLogger.