Read my 3.2 Spark Plugs Please

[LBEEMING]

1985 US 3.2 Carrera.

Can you please help with reading my plugs? Normal or slightly lean?

[LBEEMING]

[hughc]

As an amateur, I'll take a guess and say they look pretty good. Nothing to worry about.

[Uwon]

How many miles/km? We’re they cleaned off/sprayed with parts cleaner before the pic?
If reasonable mileage and straight out of the motor, I would say way lean.
M2CW
Johan

[LBEEMING]

Straight out the motor, no cleaning. They have been in for around 5000km. I will check the fuel pressure in this case. I used some injector cleaner about 1000km prior to pulling them, not sure if this would affect anything. New fuel filter too, so perhaps the pressure regulator is on its way out. Not sure how else to increase mixture other than turning DME switch to position 1.

[E Sully]

I would say they look pretty good. Very close to what my '86 looked like, and it ran great till I sold it. Today's gasoline burns a lot cleaner than the old days when a tan look was a good sign.

[proporsche]

what spark plugs are you using .you did not say..looks otherwise ok to me..here is the fuel mix procedure..

[icarp]

Yes , I agree that your plugs look very good ! Bosch 4 or 5?
The insulator has a soft white color, not hard and glossy.
The ground electrode has a soft grey color , It is tough to read the heat range as there is not a pronounced line half way through the bend on the electric ground . But still I think they are correct.
There is a proper spark ring around spark tip , the shinny microscopic edge all the way around
The black on the plug base is standard hydrocarbons , which is normal for modern fuels .
All in all the plugs look normal for a motronic injected engine .

Also it depends on how often you run it to redline , at full load , that is the only time you will get an AFR of 12.5-12.8
Light throttle will produce an AFR of up to 15.8-16.0 to 1 , this is what the EPA wants . Light throttle and high vacuum = lean AFR , so at low load no harm.

[LBEEMING]

Hi, the car currently has Bosch WR-7-DC+.

Should I be running something else instead?

Thanks. Appreciate all the comments to far!

[Reiver]

They look fine but....reading plugs today with the dif additives and corn is difficult at best.

Also, back in the day you read your plugs at wot or close to it...shut the motor off and stopped and pulled a plug otherwise you are reading them at idle only.

[EC900]

I’d say quite normal, some carbon build up flaking off one. Always a good idea to inspect plugs one at a time as it would give a better idea if/where/which is the problematic cylinder such being oil and carbon fouling, bad injector, etc.
The tan color on side electrode may be lean burn, gaskets and threads look good so no oil entering from valve cover leaks, only the lower thread has the buildup. Clean them and reinstall.

[E Sully]

Mixture looks fine, the carbon may be from your valve guides.
They were known to wear a bit on the Carrera engines. I replaced all the valve guides on my '86 engine due to oil getting past them.
What's the mileage on the engine, and has any work been done?

[LBEEMING]

Hi,

Not sure of if this engine was rebuilt, PO said he hadnt. The Speedo however only shows 14k miles. So whether the previous owner changed it when he did a rebuild I dont know. I need to do a leak down test to see how healthy she is.

[bickyd]

Pelican search feature is so frustrating. Can you tell me if a black sooty film in the tailpipe is normal? sorry to intrude on this thread but it kinda goes with it?

[LBEEMING]

I think this is a classic sign that something is running rich. My exhaust tip is clean. AFM mixture screw only adjusts idle mixture, so I'd check AFR at idle first then look to why maybe WOT and cruise is rich.

[Coastr]

Originally Posted by LBEEMING

1985 US 3.2 Carrera.

Can you please help with reading my plugs?

Hard to say but looks like Bosch to me.


Ok I will see myself out

[bickyd]

Originally Posted by LBEEMING

I think this is a classic sign that something is running rich. My exhaust tip is clean. AFM mixture screw only adjusts idle mixture, so I'd check AFR at idle first then look to why maybe WOT and cruise is rich.

Ya , what I figured. Thanks for the reply. Just needed the prod to do what i need to do, which is spend more money.

[EC900]

Originally Posted by bickyd

Ya , what I figured. Thanks for the reply. Just needed the prod to do what i need to do, which is spend more money.

Could be as simple as a vac leak causing an over rich condition. What’s the running condition and MPG been?
I’d suspect that your plugs are equally soot covered, so in any event a basic tuneup service would be in order but also without a meter in hand these tolerances will be basic and not necessarily dialed in.