Is This A Water In Gasoline Problem?

Snuffy

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May 3, 2002
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I have a 99 Pathfinder. Has run great up til about six months ago. Now, on acceleration, it sounds like a marble sack. It has little power. I have been trying to troubleshoot it...observing under what conditions this occurs. Here is what I have come up with.

It happens on acceleration.
It does not occur when the engine is cold. Need to give it 10 minutes or so.
It is absolutely terrible when I have little gasoline in the tank. The more gasoline in the tank the better it runs.

I'm thinking there may be several factors contributing to the problem. One may be that the tank has water and other contaminants and when the tank is full these rise to the top. When the tank is low these are on the bottom and enter the engine.

Any mechanics out there care to speculate? I figure that is DR related as water in gasoline is a known problem here.
 

Mirador

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Apr 15, 2004
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Snuffy said:
I have a 99 Pathfinder. Has run great up til about six months ago. Now, on acceleration, it sounds like a marble sack. It has little power. I have been trying to troubleshoot it...observing under what conditions this occurs. Here is what I have come up with.

It happens on acceleration.
It does not occur when the engine is cold. Need to give it 10 minutes or so.
It is absolutely terrible when I have little gasoline in the tank. The more gasoline in the tank the better it runs.

I'm thinking there may be several factors contributing to the problem. One may be that the tank has water and other contaminants and when the tank is full these rise to the top. When the tank is low these are on the bottom and enter the engine.

Any mechanics out there care to speculate? I figure that is DR related as water in gasoline is a known problem here.


Sounds like you are due for new spark plugs. However, consulting with a bonafide auto mechanic might help...

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Sep 19, 2005
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I am thinking that gas is lighter than water..and would be on top of the water, not vice versa.

doesnt explain the working ok on cold starts, but it sounded like a fuel filter problem....or it could be a fuel mixture problem...

when its cold it wants more gas than air...then when it warms up it wants the mixture thinned out....does the exhuast fumes smell like unburnt gas??

but it is new enough to have computer problems that could cause your issue

did you know that race cars would add a spray of water into the carb when they were reving high rpms during racing....its a boost of oxygen, and a cooler!!!!!!!!!!!!!!!!


bob
 

Snuffy

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May 3, 2002
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Yes Bob of course gas is lighter. My logic is fouled. Mirador, spark plugs are on my list of to do. Will let you know. I have a nice list of possible problems. EGR Valve keeps coming up. I will get off my butt and try to resolve the problem now.

So who has a great mechanic for Pathfinders.....Robert?
 

Mirador

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Apr 15, 2004
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Snuffy said:
So who has a great mechanic for Pathfinders.....Robert?

If you are in SD, calle Jesus (Taller Los Hidalgos), at 809-227-1854. He services my son Alan's Pathfinder, and my Montero.

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Hillbilly

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Jan 1, 2002
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In Santiago you can take it to Yaque Motors. They are not cheap, but that do very good work on Pathfinders.
There are a couple of possibilities that come to my warped brain:
1) All of the above, of course, but not spark plugs, but possibly fuel filters, the "shoe" on your in-tank fuel pump might be dirty. Seven years of DR gasoline could leave a bunch of schitt on the bottom of the tank, too. Also, remember that the gasoline in the tank cools and lubricates the fuel pump, so more fuel = better performance.
2) Off the wall possibilities: A broken air duct. When the motor revs under acceleration the motor "twists" a bit and may have broken the air ducts to the injection system, causing a stalling sensation.
3) Possible computer malfunction--Yaque can fix that.

Good luck and give us a report, okay?

HB :D:D
 

Andy B

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Jan 1, 2002
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www.elmarinique.com
Water in the gas will not cause a rattling, but will stall the motor as the carb or injector filter clogs up. Your rattling could be predetonation/knocking caused by low grade gasoline, carbon buildup or burnt valves. It could also be that the timing is off due to electronic ignition/brain failure as with the spark too far advanced these symptoms will occur. If it is too far retarded the engine will have no power (hot or cold) but will not knock. A rattling sound rather than a knock usually indicates a valve related problem, especially when the engine warms up. Knowing the way cars are treated here in the DR, the age of the vehicle with mileage approaching 100k, it's probably time for a valve job.
 

Snuffy

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May 3, 2002
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Update

From doing research on the internet and from information here....thanks for all the input...I determined that what was happening was Detonation or Spark Knock.

"Excessive Heat & Pressure In The Combustion Chamber causes Air/Fuel Mix to AutoIgnite. If you hear Knocking/Pinging on acceleration/load you probably have Detonation Problem."

I take it this means the air/fuel mixture will ignite without spark plug spark from Ignition Timing.

Now there are many things that can cause this. I decided to eliminate the easier to fix items.

Focusing on Excessive Heat.......I checked the coolent level.........I haven't checked it in a while because I probably rely to much on the dummy lights to tell me what to do and the last time I checked it...it did not seem to be using much coolant. Well, I discovered that the coolant was low. It consumed almost a container of coolant.

Results...took it out for a long drive and the problem seems to have disappeared. Now this is with a full tank of gas. I will be curious to see what happens as I near empty. I would have never thought the coolant level was related to a Knocking noise.

Vehicle appears to be very strong now and hopefully I have not done to much internal damage from all the Detonation I allowed.

Will let you know what happens on a near empty tank.

Thanks.

Now........had I taken it to a mechanic shop........I doubt they would have given it back to me with a mere charge for adding coolant.
 

Hillbilly

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Jan 1, 2002
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So true. However, I am still betting a coffee on fuel pump problems...
However, knocking is NOT fuel pump related. Be very interesting if you were overheating and not knowing it. Might want to check the temp gauge wiring while you are at it.
HB :D:D:D
 

Snuffy

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May 3, 2002
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To the contrary...

Detonation/Knocking can be caused by a lean fuel mixture....meaning more air or less fuel for good mix. These are the possible causes...

Air leaks; dirty fuel injectors...clogged with fuel deposits or dirt; a restricted fuel filter or a weak fuel pump.

Indeed I believe the problem is a combination of items and the coolant was one. Fuel pump may be becoming weak or clogged.

So you are right on that.