Speedtoys

..I can be at a stoplight, idling smooth and nice.

14.7's give/take a few tenths in the non-cat map...sweet.

Go..get to next stop light, sum bitch is pegged at 18.99....idling smoothly as ever.

Two stops at lights later, 14.7s..



TE3A, 4.2LSU clear air'd a week ago. Dip switches and firmware both set to the 4.2LSU as well.


What...the...hell...is going on?


I can be at great idle in non-cat map, put that map into the cat map, switch to force cat mode (pot disabled)..and...with the same map that shows great A/F numbers while cruising...in cat mode, im showing 17.5-18.99 constantly.


Something is seriously haunted here.

GregBBRD

The really great part of Sharktuning is that you get two of the brightest people I know to help....for free.

John? Jim?

Speedtoys

Ya...they'll be around.

I never used to get anything BUT consistent readings..I mean, at a stop light pegging 18.99 for 20 seconds, I should not be idling...at all.

FredR

Jeff,

If you were really experiencing 19 to 1, I doubt the motor would be running- at least it would be stuttering chronically I would think- I presume no tell tale signs to support the numbers?

I seem to remember someone else reporting similar behaviour- doubtless the J's will know what it was.

Fred

danglerb

Sounds like sensor/meter is whack.

John Speake

It's not clear from below whether the A/F is sometime inconsistant when in open loop, or only when you go to closed loop ?

If only when in closed loop, what is happening to O2 adjust ? What happens if you zero out the adaptation parameters and switch off adaptation before you switch from open to closed loop ?

Bill Ball

If the car is running OK despite 18.99 AFR readings by the wideband to the Sharktuner, the narrowband signal to the LH must be more reasonable.

Speedtoys

Might then blow your mind, to hear that the LH is being fed by the NB output of the Tech Edge.

Ya...dafuq??

Will confirm that true or not in the AM.

jcorenman

That can only be the WBO2 controller going wonky. If it were real then the car wouldn't be idling smoothly, so the WBO2 reading is bogus.

Do you still have a separate NBO2 sensor?

Ignoring the WBO2, does the car run OK when you do this? What is O2-adjust doing? (ST's fuel-monitor page)

Sidebar:Is this the TE 3A2 that I loaned you a year or two ago for Sean's car? ("Cal" written on by hand on the panel, to correct a labeling error?). If so, it has done this before. It would be fine for months, then go into this silly-lean mode, then if anything was changed (new sensor, free-air cal) it would be fine again for a while. The folks at Techedge were very helpful but were certain that it was an installation problem. So I replaced it with a LC-1 which worked fine, and used the TE for a portable unit where it also worked fine. That's what I meant by "it's a little flaky, keep an eye on it".

My suggestion is to replace it with something that has a gauge now that you are boosted. Maybe an Innovate MTX-L, or LC-1 with the red or blue digital gauge.

Dictys

I had the same problem with Terry's GT. It was a loose connection in John's harness giving a wonky WBO signal. Sometimes when coming to a stop the connection would be lost and the error light on the controller would come on (quick red flashing).

dprantl

+1. A 928 engine really does not like idling at above 18:1 AFR and will be very rough with lean hesitation. And if the LH is being fed this NB signal, O2 adjust will quickly peg at +20 to try and bring the AFR down. Sounds like a wiring and/or controller issue to me.

Dan
'91 928GT S/C 475hp/460lb.ft

Speedtoys

Jim: Ya..was a great price on that unit, and its worked mostly very well...so far.

3A2's aint cheap, what other WBout controllers are out there to feed the ST with?

John Speake

Techedge 2J2...

dprantl

I am running the predecessor to the 2J2 (2J1) for ~5 years now with the 928 as my DD, no issues and still on the original Bosch LSU 4.2 sensor of the same age.

Dan
'91 928GT S/C 475hp/460lb.ft

SeanR

Innovate LC1 here.