spark plugs are white

dadiesel5 · Apr 25, 2007

i have about 1 hour of runtime on my rebuilt engine and i checked the plugs and they are solid white, it will rub off if i rub it hard with my finger. the plugs are
ngk fr5 and i checked the gap and its 0.35. what does this mean?

86bluecobra · Apr 25, 2007

http://www.dragstuff.com/techarticles/reading-spark-plugs.html
Look through these articles. The links are at the bottom. Lets you know how to read your plugs.

Joey5.0 · Apr 25, 2007

White= not enough fuel.

What year car and motor?

BigHairyMonkey · Apr 26, 2007

dadiesel5 said:
i have about 1 hour of runtime on my rebuilt engine and i checked the plugs and they are solid white, it will rub off if i rub it hard with my finger. the plugs are
ngk fr5 and i checked the gap and its 0.35. what does this mean?

please tell me you mean 0.035 and even then, your plugs should be gapped at .054. oh and your running lean

Aryan15 · Apr 26, 2007

What are ngk fr5s?

dadiesel5 · Apr 26, 2007

its a 93 with a fresh rebuilt 306 with trick flow h/c/i and 65mm tb and the ngk fr5 is what plugs trick flow recommended with their heads.

4G-KDMP · Apr 26, 2007

306 or 302 i think your plugs need to gapped between .050 and .054,.035 sounds a little to close .

dadiesel5 · Apr 26, 2007

302 bored to 306 what will it change when i gap them bigger.

302RollinHard · Apr 26, 2007

Did you relocate the coolant temperature sensor when you rebuilt the engine i.e. moved it to the back of the intake? That can cause you to run lean.

dadiesel5 · Apr 26, 2007

no i didn't move anything

SoCal89GT · Apr 26, 2007

dadiesel5 said:
302 bored to 306 what will it change when i gap them bigger.

By having a bigger gap you force the spark to jump further thus giving you a bigger spark for igniting. BUT, too big a gap and you will blow out the spark before ignition.

It seems pretty much to be a standard of a .054 gap as previously stated

dadiesel5 · Apr 26, 2007

do i put on a fuel regulator to richen or how do i do it.

4G-KDMP · Apr 26, 2007

this should help it's from ngk

http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp?nav=31300&country=US#installing

3. Gapping
Since the gap size has a direct affect on the spark plug's tip temperature
and on the voltage necessary to ionize (light) the air/fuel mixture, careful attention is required. While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.
A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximizes burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.
With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think.

795.0pacecar · Apr 26, 2007

If its fuel injected, reading plugs is not an accurate way of determining whether or nor the engine is running lean unless you do a full throttle run, then immediately shut down the engine and check the plugs. EFI mustangs tend to run lean and have white plugs at idle and part throttle cruise to get the engine warm quicker, to reduce fuel usage, and for emissions. The only way to know for sure if the engine is running lean is by using a wide band O2.

A fuel pressure regulator is a band aid what wont work for long because the computer will adjust out any small changes in the fuel pressure, by adjusting the fuel injector duty cycle.

4G-KDMP · Apr 26, 2007

you didn't mention what yr your stang was but from 89 - 93 gt or lx
ngk recomends plug ur45 with a .o54 gap

ngk spark plug http://www.ngksparkplugs.com/apps/car_truck_suv/default.asp?nav=60000&country=

this site gives you 3 options for ngk and none of the options suggest using the fr5.

http://www.sparkplugs.com/results_app.asp?productTypeID=1&AAIA=1133985

are you sure you have the right plug?

dadiesel5 · Apr 26, 2007

i bought the fr5's because they was reccomended in the book that was with my heads (trickflow twisted wedge) also do you think i should gap my plugs at .054 or a little smaller since my motor is built and has a little higher compression than stock. thanks for the link.

spark plugs are white

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