How long are the 928's plugs good for, normaly?

I don't have the recomended service interval mannual.

Thanks.

 

Hmmm...

Plugs have gotten better than when the cars were new.

I'd expect 5 years for regular plugs and 7 for platinum plugs.

But can any of us wait that long?

 

How many miles.

I might put 150,000 miles on a car in 7 years...

 

Dude....when I had my first car, a '77 Rabbit [VW Golf]...they were clean for 3 weeks tops!

Of course, that 1588 cc engine was making probably 125 horsepower via a G-grind cam that wouldn't idle below 1500 rpm. All I know is that K-Jetronic hated it! That EE engine did all its work between 5 and 7k. Since this car only weighed 1800 pounds and didn't have any sort of limited slip....it had much in common with motorcycles and bottle rockets. And it did big hairy smokey burnouts! Great fun at high school beer parties-

NOT that I would EVER have consumed an alcoholic beverage before my 21st birthday or anything....



That thing burned as much oil as fuel. I recently changed the plugs on my '85 928S2, and discovered that my plugs were black and covered with soot! No oil fouling, as per my Rabbit with its worthless valve guides...but it made me purchase a set of W8 plugs. THEY made the car run a bit better, but I'm convinced that I'm still way rich [I pull the car onto the driveway, let it sit for 15 seconds while I close the garage door....and there is a soot mark on my driveway]. But 928 Specialists has an '85 European car like mine, and they have had great results by adding fuel at higher RPM's and manifold pressures.

I've wondered.....I have W8 plugs now. Can I use W9's?

N?

 

Oh the other thing is I've never pulled a set of platinums. I'm much more used to the iron nickol plugs used in lawn mowers, and small tractors.

I was expecting to see a shiny gold looking this smileing at me from the center of the ceremic.

Instead I've got kinda a black crater where the gold wire should be. I'm not sure if the crater is an optical illustion because of a bit of gunk built up around it, but here's what I know. As best as I can tell, the plug gap is the same as when I put the plugs in the motor, so any build up on the center must have been matched by errosion on the ground. I'm not seeing that much errosion on the ground. There might be a little, rounding to the ground, but again, there is a bit of crude, so it might be an optical illustion. I'm almost 100% sure the flats on the ground havn't erroded sigificantly.

That has left me perplexed.

Oh one more thing, the plugs were in service in the car when it was running REALLY rich. Since then, I fixed the AFM, and the mixture has leaned out to a more normal reading, and the soot is no longer appering on the plugs.

Btw Normy, my experence on black soot is you need to figure out where, and why, the car is running really rich. Mostly likeing it's doing this on cruise, not WOT. Fuel pressure, temp II, temp I, MAF/AFM, and ECUs are the first place I'd look. I just solved this problem. Grosely miss adjusted AFM.

 

Miles? 50k regular and 70k platinum.

I just pulled the original plugs from my ten-year old Taurus. 100000 miles. They were still good. Then again, the Bosch platinums I put in the 928 were shot after 7K miles and 12 DE days. At $19 for the set, about the cheapest real service that I can do.

 

Well, I know I'll go through them faster than your Taurus! Every mile is a fast one! Loughts of WOT. My rear tires usualy last less than half as long as the frount ones. (Opps!)

I pulled the plugs because I'vee been haveing a cold start issue, and just generaly feeling down on power. It idles fine, but just doesn't seem to have as much go as it used to. That is of coruse highly subjective, so I could easily be wrong, but thats the feeling I got and it don't cost me a dime to pull the plugs and look.

 

I've noticed more power by just changing the air filter. Funny that the filter is more than a set of nice plugs. Swap 'em at the track.

 

I've already got a new air filter. Well, it is less than 2,000 miles old.

 

Glen- make sure you put the correct plugs in your Taurus. My '97 Aerostar has a 3.0 liter engine that is the same as the Taurus, and the Chilton manual [and the Aerostar forum at Ford-Trucks.com] says that the left and right banks of this pushrod engine take different plugs-

Anyway...

Viribus, I sent my MAF to John Speake in England, and he sent me one back that he'd rebuilt and tested on his personal car, so that's covered. I'm fairly certain that my injection is working the way it should. Either I have some sort of wiring issue [though resistance across the wires from the engine to the computer is correct for each sensor], or there's some sort of oddity in the ignition that an occiloscope won't identify. I don't have any sort of air/fuel ratio meter...but Dave up at 928 Specialists has had great results with a rising rate fuel pressure regulator on his '85 S2 5 speed.

I'm serious- I've got the pot on the MAF screwed way down toward the lean setting [clockwise], and if I start it up in the garage, back it into my driveway, and do my "flow" while stopped.

[A flying thing, applied to driving: I touch my door locks button, the AC button, set the shifter, set the windows and sunroof, physically touch my wallet with a finger, touch my seatbelt, the parking brake, the rear fog light [Euro], and the headlight switch. I do this EVERY time I drive that car]

This flow takes about 10 seconds....but if I got out of the car at that point and looked at the driveway....there'd be a few drips of black water. If I let the car sit there for 30 seconds idling...you'd see a nasty black spot!

N!

 

Temp II?

I don't rember if LH has the Temp I, but if it does, check that too.

Throtal position switch? Might be stuck in WOT enrichment mode.

Leaking fuel injector(s) You can usualy identify which one is the problem because it's rare for 8 injectors to all leak at the same time. Usualy it's just a couple, and you can see the carbon build up on the plugs for those cylinder.

Finaly, last but not least, fuel rail pressure, and possibly leaking regulators and/or dampaner.