Ignition or fuel?

I have a problem with the engine heavily backfiring in the exhaust at 5000+ rpm if I put my foot into it, particularly during merging operations on the Interstate. Maybe my foot is blocking the air flow and I should take it out of the exhaust?

Anyway, a look below the hood showed a yellow sort of dust on the plug wires, and maybe one connector not quite as well down as possible, but messing around with it did not change a thing. Anyway, I changed the plug wires and spark plugs anyway, even if they were fairly recent. The way it feels, however, is much like the rev limiter feels (burning in the exhaust, suddenly total lack of power.) On the other hand, during normal driving I have an occasional stutter where the wideband oxygen sensor drops down, suggesting (AFAIK) that the fuel is not being burned, hence an ignition problem.

Does anybody have seen something like this? It cramps my style if there is a 50/50 chance of the engine refusing to cooperate with what I want to do. Before you know it, I will be ending up driving 53 mph in the left hand lane of every Interstate in the US to avoid having to merge.

Leon

Reply to
Leon van Dommelen
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Leon I know you have already checked, but by any chance, water has gotten into spark plug well?

~Cissy :-)

Reply to
Expmiata

Check your ground terminals? Any jumpiness or lagging in the tach?

Reply to
Lanny Chambers

Hi Leon,

You could have a dying coil pack. POPSTOY suggested that the terminals inside the coil pack can get corroded causing bad connections. Pull the wires and look for a white powder inside on the connectors.

Water in the gas can cause this kind of problem. It accumulates in the bottom of the fuel filter as well as the bottom of the fuel tank. Sometimes that water can be sucked into the fuel flow at WOT. A alcohol fuel additive can be purchase that allows the water to mix with the gas and be burned without the backfiring.

Three feet in the exhaust will certainly result in a yard of backfiring.

Reply to
Larry Gadbois

Are you sure the water is burned after mixing with the gasoline?

;-)

Dana

Reply to
Dana H. Myers

What Dana said. I'd try changing the fuel filter. Chas Hurst

Reply to
Chas Hurst

Thanks for all responses. I don't think I am going to mess with the fuel filter, though. I don't play golf. It is obviously more than time that I make an appointment with a shop and have them replace all suspected parts. The fuel additive sounds a good one to try right away.

Leon

Reply to
Leon van Dommelen

The water doesn't burn unless you get your foot in it!

Reply to
Larry Gadbois

I'd sort of suspect ignition before I'd suspect running out of fuel.

Dana

Reply to
Dana H. Myers

It may be. Should I tell them to test the ignition coil as per the manual, or just replace it to be safe? Anyone know how much the thing costs?

Leon

Reply to
Leon van Dommelen

When was the fuel filter last changed? When were ignition parts last changed? Ignition coils cost 10 times more than a fuel filter, that's one reason I recommend changing the filter.

Chas Hurst

Reply to
Chas Hurst

The additive seems to have done the trick. At least I had no more problems taking it out on the Interstate. With a drizzling rain, the ignition is not likely to have improved. Also seems to explain why I had hesitations at road roughness.

Thanks! Leon

Reply to
Leon van Dommelen

It goes in the shop tomorrow and they will most definitely replace the fuel filter (along with timing belt, its tensioners, water pump, power window rollers, drive shaft, valve cover gasket, accessory belts, water hoses, thermostat.) I am not yet sure about replacing the ignition coil, especially since the fuel additive may have solved the problem. Maybe I will just ask them to test it. I expect to be driving to the state of Washington soon, so I would like to minimize potential problems. It will probably already take me much more time than people expect. :))

Leon

Reply to
Leon van Dommelen

Hi Leon, When are you going to come to Washington ? If you come up from the South, be sure you stop and see Mt. St Helens. It is still pushing up Lava and it a sight you should not miss. Are you going to be in the Seattle area ? I would like to talk to you and I will take you thru the Musuem of Flight. ( I volunteer there.

Bruce RED '91

Reply to
BRUCE HASKIN

As soon as I have read the books on quantum mechanics and solid state physics. I am getting at the end of the first "course" (quantum mechanics I), but that sure must be a killer course from the problems in the book.

I expect to be at Pacific Northwest Labs. I have not looked up exactly where that is.

Sounds nice. I will give you an e-mail when I am in the area.

Leon

Reply to
Leon van Dommelen

Hi Leon,

Sounds good. I will be looking forward to getting together with you.

Bruce RED '91

Reply to
BRUCE HASKIN

If I'm going to experiment on the chance it's water in the fuel system, I'd try a can or two of ethanol-based fuel additive. Here in CA, we get to drink ethanol-dosed fuel all year long, I rarely hear of issues with water in the fuel system now. The biggest problem is for the gasoline vendors to keep the fuel "dry" before selling it.

Dana

Reply to
Dana H. Myers

Actually, the stuff I put in was methanol based. I forgot the name. A four letter word with ee, IIRC. :)

Leon

Reply to
Leon van Dommelen

Isn't "heet" a swear-word in Florida? :-)

Reply to
Lanny Chambers

I use rubbing alchohol. Cost 79 cents a pint at the super market. Methanol can damage fuel injection components. Alchohols prevent the freezing of water in your gas tank. They don't make water mix with gas.

Chas Hurst

Reply to
Chas Hurst

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