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So been driving my bought back to life 1985 Porsche 928 and noticing that it drinks gas. I don't know the MPG but I know 1 hours worth of driving is about $20 worth of gas, and that's pre Ukrainian crisis prices. Gas gauge is a little funny, in that 1/4 is empty. I'm guessing that Porsche really wanted people to refill sooner than later? This is one plug that I removed so someone can tell me how it's running as @GregBBRD advised. Yes I know those aren't Bosch copper plugs, as I wanted to put in Platinum's for a hotter burn. I do have a good set of Bosch copper plugs I removed from this engine as it seems someone had just changed them before the car sat. New wires and new fuel injectors. The injectors people talked about that have four holes instead of one hole. The original fuel injectors were a little locked up until you ran the engine for a while. Also the engine did smell like it ran rich for a while until I fixed all the vacuum leaks and changed the plugs and wires. Now there's no smell and the exhaust is clear when at operating temperature. I haven't gotten around to putting in the air temp sensor some people here recommended me to do. The Bosch 0280130085 air temp sensor. A bit more work to get that on there. Advice is welcomed.
NGK plugs are great and definitely a solid substitute for Bosch. I run them in my 89 with 0 issues and have done for 5 years now.
But for anyone reading this Porsche specs the WR8DS plug for use in the 85-86 32V engine. At least that is what it says in the owner's manual
Just be prepared for the sticker shock
The WR7DC+ people use is too cold. You're leaving power (and lower emissions) on the table!
That's good to know. I don't know what the old plugs are exactly because I'm too lazy to go check but they looked new. So the burn on the plug looks normal? I'm still shocked how much fuel she burns when getting around town. Might explain the huge gas tank this car has. Anyway to make the engine run lean? Not super lean just slightly lean. You know what they say, leaner is meaner, plus it uses less gas.
From my experience she should use outside of town 13 l 100km. In town 17 l isn´t too much. On fast overland trips 15 l.
Stop and go isn´t the natural enviroment for our cars! With a stick you haven´t fun.
NGK plugs are great and definitely a solid substitute for Bosch. I run them in my 89 with 0 issues and have done for 5 years now.
But for anyone reading this Porsche specs the WR8DS plug for use in the 85-86 32V engine. At least that is what it says in the owner's manual
Just be prepared for the sticker shock
The WR7DC+ people use is too cold. You're leaving power (and lower emissions) on the table!
A Bosch heat range 8nplug is also available in copper at regular prices, just change the S to a C on the plug number, so a WR8DC.
The higher compression Euro S engines run one heat range lower (So a 7 in Bosch) and if forced induction should go one more colder (so a 6 and some even run a 5).
For NGK plugs the heat range works opposite as Bosch (the bigger the number, the folder the plug). An NGK heat range of 8 is equivalent to the Bosch 7 so if looking for the stock heat range equal to a Bosch 8 you need an NGK 7 so a BR7ES or BPR7ES for projected.tip.
The onset of bat MPG..if you track it and can see it, can be an O2 sensor going south.
They will fail 'lean' and richen up the car.
On this years ****about road trip, Im getting between 15.5 and 19.5mpg on 2.73 rear end, mostly cruising 80-95mph. Currently in Pueblo, CO on the way back home on the northern leg. (map was original plan, I skipped Tulsa)
I have used 3/4 of a quart of oil since leaving home on Feb 25th.
Nope because I have to fill the tank and that is scary right now.
Originally Posted by Speedtoys
The onset of bat MPG..if you track it and can see it, can be an O2 sensor going south.
They will fail 'lean' and richen up the car.
On this years ****about road trip, Im getting between 15.5 and 19.5mpg on 2.73 rear end, mostly cruising 80-95mph. Currently in Pueblo, CO on the way back home on the northern leg. (map was original plan, I skipped Tulsa)
I have used 3/4 of a quart of oil since leaving home on Feb 25th.
Someone in the past had changed the O2 but who knows when that was. It does look changed like maybe before it sat but who's to say? Does it running rich show up on the spark plug photo I've shown or it's not enough to see it?
It's running rich, you can tell from all the loose black carbon buildup around the edge of it. That should be fairly clean.
It is however running well otherwise and getting up to temp to clean the electrodes so it isn't pig rich.
You can google how to read spark plugs. There are guides and videos everywhere to tell how well or poorly your engine is running from the plugs.
This shows that my engine is running perfect, so not much help. So what could be the cause of it running rich? It does have a bouncing idle that occurs once in a while but then runs normal again. I could try doing another smoke test to see if another vacuum leak popped up. Maybe remove the O2 sensor and clean it or at least examine it?
Turn the pot on the MAF CCW 1/8 of a turn; that will lean the car out a small amount. As Speedtoys mentions the O2 needs to be in good shape. Replace it with OEM only (Bosch).
Does it smell like raw gas when you are sitting at a traffic light after all warmed up?
Turn the pot on the MAF CCW 1/8 of a turn; that will lean the car out a small amount.
What pot to the MAF?
As Speedtoys mentions the O2 needs to be in good shape. Replace it with OEM only (Bosch).
I saw that somebody had replaced it but didn't put the plug to the body on correctly. I figure I'll take it out for a cleaning once I get around to changing the transmission oil and diff oil.
Does it smell like raw gas when you are sitting at a traffic light after all warmed up?
It actual smells good once in closed loop. It's when you start it cold is when you see a little white smoke out of the exhaust but I thought that's normal for open loop, as it is in most cars.
Last edited by dukenukemx; 03-24-2022 at 12:22 AM.
1 hours worth of driving is about $20 worth of gas, and that's pre Ukrainian crisis prices.
All the gas price PAIN is SELF-IMPOSED! It is also planned, look into "ESG" .... Call your reps/sens and tell them to STOP supporting the lamebrain puppets war on US oil! $2 to $4 that never had to happen, plus gas prices are what drives ALL OTHER INFLATION! (except for housing which was self-imposed by near 0% fed funds rate for way too long)
My euro runs like a top when running. I use NGK V-POWER BPR6EY, now that is for a euro with higher compression.
These cars consume gas like no tomorrow especially if you drive it for enjoyment high in the RPM's. It's not a daily. On the highway you could get acceptable numbers but 12 would be good on a fun ride.
03-20-2022, 07:00 PM
Fuel consumption seems high
