Every winter my TA seems to gas foul #6 and #8. It's only those two plugs. Could this be my battery running low and not putting out enough spark? Any ideas? I'm getting tired of taking off the starter to get to these plugs. Also, can I get a hotter plug or run less gap?

Thanks,

Mark

 

You have provided next to nothing as far as information. Have you checked the wires in several different ways? Does it run fine in the warmer months? We would assume so based on what you typed. Have you checked the injector spray pattern against one from a good cylinder? Have you ever done a compression check? What lead you to find those plugs being fouled? I can keep going with questions all day but I think you get the point?

 

Your spark plug gap question makes me wonder if you're still running the stock plugs/gap. As a rule of thumb, you should go with plugs one heat range cooler for every hundred horsepower you've added. Have you stayed stock or changed the plug range. For your setup I'd suggest you switch to NGK TR6 plugs, gapped at .035" My idle smoothed considerably by tightening up the gap and there is less likelyhood of 'spark blow-out'......

It is possible that low voltage has an effect on the ignition system but it would hard to understand why 6 and 8 are the only ones fouling. If you haven't tuned up the car lately, it might be time. Plugs, wires, cap/rotor, air filter, fuel filter would be the best place to start....

Good luck!

 

I'd look for evidence of cross-firing between the #6 nd #8 plug wires.

Also check to make sure you have the correct harness connectors on the #6 and #8 injectors.

 

Is it possible you have a leaky fuel pressure regulator? If fuel gets in the vacuum hose, it can dump it on the #6 and #8 cylinders.

 

Sorry, I have not done much testing this time around. Usually, the plugs are wet with gas and my buddy that is more mechanically inclined than me tells me they are gas fouled. This problem happens only in the winter after it sits for 3 or 4 weeks. I always forget to put stable in the gas because I think I'm always going to drive it. It runs fine in the summer or warmer weather. This makes the 3rd year it's done this. The plug wires show they are firing. I have tested the wires to the injectors with that glow plug(thing?). The opti & coil & control module are relatively new. I have never taken the time to test compression. Fuel pressure is fine at the rail. I will double check the injector wiring. How do you check spray patterns? I may swap injectors with #2 & #4. Where is the fuel pressure regulator? What is the difference in NGK TR55 and NGK TR6? By the way my TA has always run rich.

Any other ideas are greatly appreciated.

Thanks for your help,

Mark

 

My back plug,passenger side ,used to foul,heavy gunk,till I got the intake manifold gasket replaced.Beer time here.My02.

 

Here's your answer.

First off, Sta-bil or any other stabilizer is not your problem. Not if the problem has occurred over the last 3 years. A clog would more likely occur not a leak.

The bad regulator will cause it to run rich all the time. Shown here:

Regulator

The diaphragm is probably leaking and allowing fuel into the vacuum hose. Check it for leaks. As mentioned above.

 

How do you test a leaky fuel pressure regulator?

Thanks again,

Mark

 

Check the vacuum hose for the presence of fuel or fuel vapor (kinda like my first post indicated).