Petza914

This is good to hear because I just bought NGK BPR6ES for my 84 Euro and was a little torn on which heat range to select.

tv

Yeah I noticed what you said about NGK being opposite of Bosch. Well here is what I can say, I was running NGK V-Power back in 07 when it was running GREAT and I had used 2 other brands before but was not super happy with them. (and I was fully aware of the heat ranges and changed brands because of that once) Now when I changed the older NGK's last year for new ones because of all the sitting, I have to assume I was smart enough to look at the old ones to get the same ones new. (I think I have the old ones in the garage with the car)
These new NGK's were running great with the new 4 hole injectors. It never sounded better before the HG went. (the engine was also running nice and cool with these, though the plastic covers being discarded played a role)

Jerry Feather

As to the gas consumption I suspect that you are missing a very likely culprit. You need to check that your Fuel Pressure Regulator and the Damper(s) have not failed in that the vacuum diaphragm in one or more of them has ruptured thereby allowing fuel to be sucked into the intake where the vacuum is created to operate them. I think that could also affect your idle.

I think also that there is likely some misunderstanding about the heat range for Spark Plugs. None of that has anything to do with the heat of the spark being produced, but rather the amount of heat that is allowed to build up in the body of the plug for the purpose of fording off plug fouling.

dukenukemx

I recently checked on them and no leaks. I took a vacuum tester and tried to see if any fuel would come out of the vacuum line. Nothing. At this point I accept that this car just eats fuel, and Porsche knew. That would explain the funky gas gauge where 1/4 is also empty and why the tank is something like 23 gallons. I gotta calculate my MPG to get an accurate idea how it goes.

I took a moment to remove the MAF and turned this screw 1/8th counter clock wise as instructed by @Rob Edwards. Gotta see how the gas burning goes like this. I'm not expecting miracles but I prefer to run my engines a little lean. Here's my MAF.

928NOOBIE

Sometimes the pot is adjusted to compensate for vacuum leaks; I am guilty of this behavior. If that has been done and the leak(s) get fixed; like when an intake refresh is done; the MAF would most likely run the car over-rich; too much can prevent the O2 from correcting enough/quickly enough to compensate adequately.

We want to know what the MAF setting is currently sitting at. Check it using ohms.

Take the multimeter and attach to terminal numbers 6 and either 3 or 4 on the MAF itself if it's still out of car (alligator clips work well for me) or if the MAF is installed disconnect the LH connector and attach to pins 14 and 25 (ground) - 14 and 25 are both are on driver's side of double row of connectors; 14 is at very top, 25 is the bottom one. Mid point for the MAF ohms setting is 380. Give us the data...must have data. We love the data.

As an FYI and a personal recommendation for tuning purposes its obviously faster to check MAF setting through the LH; I got some junior timer connectors and made a set of wires to plug onto the LH terminals. I have used alligator clips before I made my test kit.

GregBBRD

Correct, Jerry.
But there is quite a bit more to that story, which I've been trying to get people to understand:
Long before the diaphragm in the stock fuel pressure dampers fails and dumps fuel into the intake system (which means the diaphragm has to actually crack and leak), the diaphragms have gotten rock hard and no longer move, which is required for them to do their job.
The result is there are significant fuel pressure surges in the fuel rails (which the dampers are supposed to control.)
This creates both rich and lean areas in the rpm range, depending on what the pressure surge is doing.
The O2 sensor attempts to "chase" the fuel mixture, but the pressure surges occur way faster than the O2 sensor can respond....or even show the issue.

The point is:
The fuel injection system is a....system.
The individual pieces are all dependent on each other.
Trying to tune the fuel injection system, which can't function correctly because of bad parts, is a fool's errand.

Darklands

My engine in the S saws sometimes at low idle and sometimes I have micro shut offs at driving. Sawing is the result of the pressure peaks, right?

GregBBRD

Perhaps.
Surging at idle is almost always too much fuel.
Not sure about the micro shut offs, while driving.

gb

Darklands

Thanks Greg,
the next time on the Dyno I should measure air fuel ratio.
Without hard data I think is leaning these engines with the dump computer’s dangerous.

GregBBRD

Yeah, making generic changes to an engine's fuel or ignition system, without gathering data about what the effects are, is really a gamble.
For this reason, "generic" chips are a terrible idea.

One of my mentors, who taught me a bunch (in my youth) used to have a great saying about running lean and running the ignition timing right on the "edge" (on a drag race boat.)
"You really aren't making optimum horsepower, unless the inside of your exhaust pipes are metal sprayed with aluminum, from the pistons, after every run."
He also never ran a tachometer in any of his boats:
"If you're behind, you need to go as hard as possible. A tachometer is only going to make you "lift" off the throttle, and slow you down."

Darklands

Speed is a question of money, how fast want we to go?