Sean, was that tested on the car pressing the pedal to rotate the the throttle butterfly ?

The switches I have tested off the car WOT activates at about 2/3 to 3/4 of full
rotation of the butterfly.

Andy's definitely described it as happening when he hits the Kickdown switch which to my mind should be significantly beyond triggering the WOT switch.

I'm thinking that erratic connections/melted wires at the rear of the CE panel are more likely cause. That or ignition related problems.

Doesn't explain his 1500rpm idle condition though - that has to be either a stuck throttle linkage, false air, or the ISV sticking open.

 

Idle was more like 50-500 with the O2 sensor plugged in. The car is ROW and an illegal alien now with the O2 hooked up to an NB AFR gauge.

 

Try restoring/reconnecting the O2 sensor & see if the problem persists. Your ROW pot is just covering up the real problem, if not causing your current one.

 

I agree. It was great to take the O2 loop out though in ROW mode. It actually may have revealed the actual problem instead of just masking it.

 

I am going to change the coding plug and disconnect the potentiometer tonight. If I have some time I will pull the CE panel and have a look behind it. It never cut out at high RPM until I went to ROW non-cat.

EDIT: No time to do it tonight. I'll try tomorrow when there's light out and can drive it with the O2 activated again. I'm going to splice in the AFR gauge to see if the O2 sensor is functioning. I should be seeing the LEDs cycle between lean and rich indicating proper functioning.

On a side note, all my idle problems disappeared when I went to ROW non-cat coding, but it started this cut out issue.

 

I have been thinking about those ignition modules in the front. How long do those usually last? My car just turned 156,000 miles the other day.

Looks like I won't be able to work on it until Saturday. I will be missing Sharks at the Park this year as this car is no longer trustworthy in the condition it's in.

 

Take your DD. It's a fun event, you should not miss it. I think they'll forgive you if you don't show up in a 928, just this once!

 

Andy: If your only problem is floored above 4500 RPM, you know these cars have plenty of low-end torque below 4500. You should be fine for a ride over to Berkeley to the picnic. Hope to see you there.

 

Should I just leave it on ROW then? If I go back to my original coding, I will have O2 loop issues, guaranteed.

 

Your engine didn't stall out at WOT with the O2 connected, correct?

No-brainer to me...

 

No but it barely idles closed loop.... another no-brainer.

 

Let's see... annoying idle problem or potential tow due to fouled plugs or plugged cat? You know how fun drives go, you'll hit WOT from time-to-time.

 

It would seem that after so many months of issues...

and...

with an upcoming local event where a couple of dozen 928-ers gather, most with good experience in this area of diagnostics...

I would resort to towing this car, even by mule train, to the SITP event (LOCAL), so that the issue(s) can be diagnosed by wise folks with real experience...

possibly leading to even fixing the isssue, hopefully once and for all

I think the opp would seem priceless

 

Are they original plug wires? I had some weird issues with mine last year that resembled yours. The wires looked ok but once I replaced this it was a totally different animal and cured all problems I had. Engine ran much smoother as well.

 

New plug wires from Roger. Connectors on both sides are fine which was why I bought the wires only.

I will TRY to make it to the event, and it will be coded as US with O2 and not ROW. If I can't get this damn thing fixed I'll trade it for OB. We never had the problems with an '85 as we have with an '87



EDIT: Not going....Official. FIL is coming over and wants to go shooting and dinner for helping fix his Escalade in the afternoon. I have the morning to go corrosion hunting in the CE panel and grounds as well as put a new O2 in.