Why are my plugs fouling??

[pattejam]

Hello all,

About a month ago, my '91 was hesitating under load. (between 1500-4000 rpm) I replaced the spark plugs with new NGK's. The car ran great. Now, the problem has returned. I guess that I need to find the reason the plugs went in the first place.

Could this be an O2 sensor? Can I test these somehow?


Also, how sensitive is the engine to overheating? Are these cars known to blow head gaskets when they overheat?


Thanks in advance for any advice.


Cory Patterson

 

[ScienceofSpeed]

Cory -- Do you have anything aftermarket on the car? Any adjustments to the fuel system?

-- Chris

------------------

http://www.NSXClassifieds.com - free NSX classifieds site!

 

[pattejam]

Hello,

I have recently put an intake on.

That is the only thing.

Thanks
Cory Patterson

 

[DanO]

Hi Cory

It sounds to me like something is wrong with your engine. When you say that your plugs are fouling, what exactly do you mean? Do they have carbon buildup on them? On all of them, or just one or two? What do the other plugs look like? Since you just put new ones in, it may be a good idea to take them back out and see which one(s) are messed up. How does your engine sound at idle? Does is sound smooth when you rev at idle to 3k or so?

Why do you want to know about overheating? I imagine that running the engine at temps higher than it was designed could cause some damage, but these engines don’t usually run that hot unless there’s something wrong. Is your engine running hot too?

DanO

 

[pattejam]

Hello,

The engine idles ok. If i rev it from idle, it shakes a little until about 3000 rpms and is smooth all the way up after that.

I had a bad thermostat and the engine overheated. This happened in my old car and it cost me a new head-gasket.

I will pull the plugs this weekend and check them out.

Thanks

Cory

 

[Harvey Wong]

My 91 NSX overheated one time, but it turned out because there was air in the heating system ( I have not changed the cooling liquid for a long time ). After I flushed the system and replaced the liquid, the heating is fine.
Harvey Wong

Originally posted by pattejam:
Hello,

The engine idles ok. If i rev it from idle, it shakes a little until about 3000 rpms and is smooth all the way up after that.

I had a bad thermostat and the engine overheated. This happened in my old car and it cost me a new head-gasket.

I will pull the plugs this weekend and check them out.

Thanks

Cory