UPDATE of previous post
I am experiencing an intermittent problem with sudden loss of power and bogging down. with my 95’ Ram 1500 (318 ) at freeway speeds engine suddenly loses power and runs terribly and will run only with minimum throttle and with too much throttle will backfire and possibly die after I pull over and wait five to ten minutes engine will usually run perfectly again this problem can happen after five miles or five hundred in hot or cold weather. I do not smell any gas fumes
In fact I first had this problem in Florida and it resolved itself then drove to California with no problem now problem is back I have replaced EGR and control solenoid (found it melted due to contact with exhaust system), cat converter, temp sender, and a few other sending units checked for exhaust obstructions. I also noticed that there seems to be a vacuum in the fuel tank when the problem occurs if I loosen fuel cap I hear air rushing in past the cap? the cap passed the cal smog test but I have replaced it with a new Stant replacement still get vacuum or possibly pressure but it sounds like a vacuum is this normal could a vacuum be forming in the tank and causing the fuel pump to be slowed or stopped? Maybe that would explain the intermittent problem at freeway speeds? And now just replaced Evap purge solenoid but problem remains there are no trouble codes being generated. Any ideas would be greatly appreciated since my girlfriend[8D] lives around 300 miles away and this could happen a couple times a trip! One of you guys must have an idea.
Bob (Rocdad)






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R O'Connor

 

I have now changed out crank sensor, cam sensor, rerouted wires per tsb, new stock coil, changed out Bosch platinums with stock plugs, changed out gas cap, bought fuel pressure gauge pressure seems fine the problem with engine bogging down still happens after long drives at 65-70 mph I live in California and want to drive to New Orleans to help victims my prevous post have not gotten any replies please respond it you have any ideas.

Not sure if related but since I changed out gas cap seems like moisture actually water accumulates in cap?

 

Could be Vapor Lock

While you are traveling the high country this summer, and your car becomes weak, irritable, tired or just plan dead, it may be suffering from vapor lock.
Vapor lock is the result of high altitude, high temperatures, or a combination on your car's engine. Vapor lock can occur at any altitude due to heat, but it is more common at higher altitudes, because gas at high altitudes vaporizes at a lower temperature. The resulting gas/air mixture can slow down or even stop the flow of gas to the engine, especially if your car is not designed for high altitude travel.

The key symptoms that your car is suffering from vapor lock is a loss of engine power, a rough running engine, and/or a engine that will not start. To reduce the chance of vapor lock, avoid running the air conditioner, and at the first signs of power loss, shift your car into neutral and rev up the engine. Finally, be sure to shift to low gear when climbing.

If your engine won't start due to vapor lock, here are a few good tips you may want to try to get it started:


First, loosen the gas cap. Be sure to stand back when doing this because gas may spray out at you.
Second, remove the air cleaner cover and hold open the choke flutter valve in the carburetor with a object, like a screwdriver. Be careful - backfires can occur.
Third, start the engine, holding the gas pedal all the way to the floor - do not pump the gas.
Fourth, wrap a wet cloth or cloth with snow around the metal fuel line near the carburetor (trace fuel line to make certain it goes to the carburetor).
Finally, let the motor cool at least 30 minutes before trying to start the car.
Try this a few times, but don't over do it or your car battery will die.

Also when was the last time you changed your Fuel Fliter.
Also try to leave gas cap loose dont tighten all the way.

 

Thank you for replying to my post in over a year you were the first to at least try to assist me unfortunately this occurs at all altitudes in fact usually at near sea level during this time I even drove over Mt Lassen the highest highway in the west without problems it happens in all weather and seasons. What is consistent is the truck has been running at high speed for at least a hour or more it also will fix itself after cooling somewhat.
some other points the dodge Ram does not have a fuel filter that can be changed out, I do seem to notice a vacuum on the gas cap during these times but loosening the cap does not seem to affect the problem much. If I limp home with the problem the next morning the engine will still have symptoms for less than a minute till it seems to clear itself, The Dodge Ram is fuel injected so no carb problems.
Thanks for the input.

Bob

 

Here is one example i found from doing a search. sounds like something is heating up and causing the issue.

"Can someone please help. I've had my 95 Dodge 1500 for around three months now. It has 100,000 miles on it. Whenever I drive it for more than 30 minutes or so, the truck starts to "sputter" and it stalls out. After it sits for a while, it starts back up and runs fine. I talked to a dealership and they told me that it sounds like the fuel pump module, which is of course inside of the gas tank. Dealership wants over 700.00 to fix. Could it be something inside of the gas tank? I thought it was water in the gas when it first happened, but i don't believe it is. Any help would be appreciated."

 

An after thought. have you looked at the evap system. Over time the charcol inside can loosen up and the purge system on them can plug up.

 

Yes I have thought about the Evap sysytem in fact I replaced the Evap solenoid I will take another look at the canister but if I remember right it is sealed. My next task right now is the fuel pump shows great pressure when testing in the driveway but I am trying to locate a extension hose for gauge so I can put gauge in front of windshield tucked under rear of hood and monitor during the problem times.
If you are right about the Evap charcol getting loose what would happen? I have noticed a vacuum problem during the event with air rushing past cap but I have tried running with no cap and it does not seem to affect the problem much.
And I do not know if it is related but everytime I get gas and take off the cap I can shake water out of the cap?

Thanks for the reply and taking the time to suggest answers.

Bob

 

Finally! I've been searching the net for answers to my problem, which is the exact same problem as yours. (Except for the water on the gas cap and my problem is constant, not intermitten). I am in the process of replacing all the sensors to the throttle body, O2 sensor, coolant sensor, and what ever sensor I can find. I was also told that it could be the catalictic converter or the fuel pump. I took it to a mom and pop shop to have it put on the snap-on diagnostic scanner and the old man told me that my computer or power control manual was shot. He told me this becouse it put out code code #10 and #49 which according to the scanner, those codes are undocumented. I refuse to believe that it's the computer, and I hope that it's not the fuel pump as it appears to be a pain to pull out. Only because I am regretting emptying the tank.
Well, if I run across the fix for my problem, I'll post it here so you may try. I'd appreciate it you'd do the same if you find it first.
Thanks again! Peace out![8D]

 

Just curious if you fixed it? I still have problems and need to drive to Nevada in August.
Thanks

 

Nope, not yet! I removed the cat. converter and ran a flex pipe. It ran like a champ for about 20 miles and then started to act up again. Now I think I am having a problem when it gets hot. This truck is driving me nuts already. I've redone the obvious. Sensors, tune up, cleaned the injectors and replaced the gas cap. Now, it looks like I will have to check all the wiring. I will start by consentrating on the distributer and go from there. If I find it, I'll let you know. Let me know if you get yours running like new again. Thanks!