Sparks coming from the idle adjustment screws?

Can't be normal right?

I decided to adjust the idle as she was idling warm at 1,200 RPM. I didnt know that the adjustment screws are hand tight. So I grabbed a wrench, waited for the fans to kick in and the wrench sparked when it made contact with the adjustment screw and the housing.

Good news is that I turned them clockwise (by hand) about .5 turns each and the car is idling much smoother now, just above 1,000 RPM.

Christian
1990 US TR

One more for the collective, my left hand window switch is forward of the left hand window switch on the center console. The Ricambi parts diagram shows them reversed. Kinda weird as they are different part numbers but i want to replace the right switch as it sticks in the Up Position.

Back to the garage.........

 

Yea, the Drivers switch is forward of the Passengers switch. Haha Thats an easy fix.

Now what about the Sparks?

 

I just bought a volt meter yesterday so bear with me. I have the dial set at 20 on the DCV range. With one probe on the set screw and the other probe on the housing I get nothing. With one probe on the housing and the other probe on miscellaneous ground. I get .40. So that led me to believe that the whole housing was getting a current....same reading on the entire left intake housing..... .40ish.

When it did spark, the car stalled momentarily. That was enough to tell me dont try to recreate it again.

 

Will check in the AM.

 

Couldnt wait, Ground strap was a little dirty. Pulled the strap, cleaned it, sanded down the ends to bright metal, same with the two washers and nuts.

Ill start her in the morning. Not too terribly concerned as there are grounding points on the lower intake manifold on the right side by the 7-8 fuel injectors.

 

OK:

1. The 'other ground' I was referring to is between the 5 and 6 fuel injectors on the intake plenum. The 'other ground' was just an observation that Im assuming some current must pass through the plenum by design, as there is a ground for it. I wasnt using it for readings, just an Ah-Ha moment.

2. Yes, the entire 7-12 upper intake plenum.

Hope this clarifies things a little.

 

Thanks Tim for the pic. I didnt measure the grounding point in the picture above, just on the left side upper and lower plenum. I have to give this a rest for the weekend as Ill be in Vegas for work. Ill take some more readings on Monday (or Sunday night if the wife doesnt see me sneak in.)

Christian

Good news, before it would idle about 100 RPM too high and bounce up and down on a cold start. After the adjustment the bounce is only a few seconds then 1,100 RPM.

 

I had my buddy over for dinner. He is a Senior Tech with Porsche (35 years) and we played with the volt meter. .01 max everywhere we measured. Cold, warm etc....nothing over .01. He was familiar with the fuel system and took readings off of the the alternator, engine ground, plenums etc. all normal. My readings were gone. Cant explain it, pulled out the wrench and no sparks/arcing at all.