Weird Problem

sroosr · #1 04-25-2004, 11:37 PM

I have a 1996 van. It's a Dodge Ram 2500 V8 with 84,230 miles on it. The problem is when the gas tank gets lower than 1/2 full it loses power, back-fires, accelerates very slowly and will only go up to about 30mph. Another thing it does, but not all the time is when it does get up to 30mph it will begin to slow down as if you were letting off the accelerator; then after a minute or so it will slowly get back up to 30mph. Now to confuse things even more, it will completely and for no apparent reason stop doing ALL of these things and begin running normal again. It may take a few days before it starts running bad again or it may take 4-6 weeks. A mechanic I used for the first time said the problem was the fuel pump. So he put a new fuel pump on it and it was fine for about 6 weeks and then it started doing the same thing. So I don't know if the new fuel pump went bad OR was installed wrong OR the fuel pump was not the problem at all and it was just time for it to start running bad like it used to do before the new fuel pump. They are going to look at it again this week, but I'm just not real confident they know what they're doing. Has anybody had or heard of this type of problem? Thanks for any help.

bignoisey · #2 04-27-2004, 10:10 PM

Water in the gas will cause this. There are fuel additives designed to dissipate water in your gas - try that first. The lower the tank level, the more percentage of water to gas in your tank. But you also may have contaminated gas in your tank. Sediment may be clogging your filter or strainer in the tank. Check to see if you have an external fuel filter and try changing it. If the mechanics pull the pump again, they should check for contamination. If you do have a bad load of gas, you'll probably have to pull the tank and get it cleaned thoroughly to make the problem go away completely.

slantsixness · #3 05-03-2004, 12:57 PM

Bad gas and/ or water. Try drygas (ethanol) in it. It should help. You can get it at auto parts stores and truck stops.

Also, but this is RARE;
I have found in some vehicles bags, rust, plastic parts and Gas Can nozzles down in the tank, which when the tank is low on gas, will restrict the fuel to the pickup, so, if the drygas doesn't fix it, take the tank out, then the sending unit and see what's up with it.

Don't buy crap gas from cheap wholesalers anymore, if that's what you did....!

Good luck,

Slantsixness

greatbarralbion · #4 11-02-2004, 07:24 PM

Sorry No Help But I Have The Exact Same Problem On The Exact Same Model And Year Realy Weird

Ramcamper B-350 · #5 11-03-2004, 06:05 PM

check if its a mechanic or electric problem. to test it unplug the wire from the gas fuell sensor of the gastank (in any point of the line you can cut and repair easy). Reiner

wpatters1229 · #6 11-29-2004, 09:35 PM

I have a problem that started right after my wife filled up a few weeks ago. This is a 1992 B350 with the 360 FI engine.
When it warms up and you are traveling with very minimum acceleration it will "cough" just almost like a backfire through the carb. In fact that pretty much describes it. If you floor it the van takes off like a scared rabbit. I thought it would start failing when I took up a steep hill.....just goes great but if you are going 25mph and ever so slightly start to speed up it will do it's cough. I checked everything but the fuel filter because I have been told it is in the gas tank.
Would a clogged filter do this? I thought it might be water in the tank but I've added some additive that is suppose to clear that up and it still does it's cough. No engine codes. Doesn't do it all the time and at 70mph for two tank fulls it only did it trying to get up to 70 and then ran without a hickup until I had to stop again for more fuel.

Any ideas?

89ltd · #7 11-30-2004, 01:48 PM

sounds like an egr valve opening to soon, try pulling the vacum hose off and plug it with something and see if it helps. The valve should not open right away, only at higher rpm and when it is up to temp.

wpatters1229 · #8 11-30-2004, 03:16 PM

That makes sense.....It has been very cold here lately and my wife says it ran fine until it warmed up and then it started the coughing. Does that sound like it is along the same idea?

wpatters1229 · #9 12-03-2004, 05:42 PM

Quote:

Originally Posted by wpatters1229

That makes sense.....It has been very cold here lately and my wife says it ran fine until it warmed up and then it started the coughing. Does that sound like it is along the same idea?

I tried that; pulled the hose off the egr valve and plugged it. Still did the "Cough".
The other option is to pull the gas tank and replace the filter and pump. I hate to do that because I just don't know for sure if that is the problem. It would seem that temperature wouldn't have a thing to do with it and if you running at freeway speeds of 65 or 70 it runs perfectly for hours.

I think I will live with it awhile. Maybe it will get worse and show it's true self. I thought of replacing the wiring, plugs, cap and rotor just because that is the easiest thing to do regarding a tune up. Everything else is either the computer or some smog device that is also a mystery to diagnose.

cwalker842 · #10 12-06-2004, 12:36 PM

Hello,

I have the exact same year and model van with the same problem.
When the tank is less than 1/4 full and cold, I lose power, backfires, goes about 30 mph. I get multiple cylinder misfire codes.

Did you ever find out the reason it was doing this?

Thanks

wpatters1229 · #11 12-06-2004, 01:33 PM

I don't get any codes....I assume the red engine light comes on when you get a code. That doesn't happen. I removed the vacumn line to the EGR valve and plugged it. Suggestion was that it might be that....no fix. Waiting to see if it gets worse. I hate to have to drop the gas tank and replace the fuel filter and pump.

wpatters1229 · #12 12-14-2004, 01:23 PM

update on problem....I found out the fuel filter is outside the fuel tank so I was able to replace it. I also replaced the ignition wires, plugs and cap/rotor. Also added some HEET to "again" remove any water in the tank. Seems to have fixed the problem. The guys at the parts place said it was probable the fuel filter since the fuel injected throttle body carburetor is very sensitive to dirty fuel.

shutupalex · #13 09-17-2005, 03:17 PM

Mmmm, I feel sorry that all of you are seeming to have the same problem I have. I've been chasing this ghost now for a year. I have replaced everything (and I do mean everything) from the fuel pump to the injectors. From the spark plugs to the distributer. From the exhaust manifold to the muffler (even that stupid warm up valve in the exhaust manifold I've wired open). All filters and any other thing I could possibly do short of driving it off a cliff. It has been to Dodge and they cannot detect anything. For some reason this problem will not trip fault codes. It's quite frustrating when they tell you it runs fine, charge you a hundred bucks for looking, and you end up stranded in the mountains anyway. I have an increasing suspicion that the engine computer is at fault.

rhinologistics · #14 09-30-2005, 02:33 PM

I Have The Same Problem But At 3/4 Tank Did You Figure It Out???

fredjacksonsan · #15 10-18-2005, 09:38 AM

Try not to bring back old threads(this one was 9 months dead); you'll probably get a better response by starting a new one with some details about your vehicle.

Also, check the Ram Truck forum, there are numerous posts dealing with the exact same issue, and several fixes noted.

Good luck with the problem.....

Mike

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