Any Dodge experts?

[WrenchDad]

I have a 1999 Dodge Ram 1500 4X4. 318 magnum automatic. Here's the problem first I get terrible gas milage 8-10 miles I know it's an eight cylinder but it should do better than that. I know that could be a lot of different things, but yesterday as iwas driving it just shut down like it ran out of fuel (yes I had gas) It started right back up . I was only 100 feet or so from home so I pulled in and shut it down. Today I jumped in to take my grill to my mother in-law's house(about 3/4 mile away)No trouble on the way there or the way back. Later I went to leave to go back to mom's, I started the truck (but didn't put it in gear)and it ran for about a minute and then died out again. it wouldnt restart (like it was out of gas) I got a ride to mom's and when I got back I tried to start the truck. It started right up even reved up then about 45 seconds it died out again and wouldnt restart. As it dies out It sounds like it is sucking air through the filter but there is no fuel to burn.
My first thought is fuel pump But I'm not a Dodge man so it is just a guess. what puzzle me is why it starts back up after it sits then cuts out after a little while.....Maybe vaccum leak :shrug: Has any one else run into this or know what it might be. If it was a 5 HP briggs I could figure it out, this is a little more difficult for me.
I could use any help you have, thanks in advance.



Kirk

 

[TomH]

first thing I would do is pour in a can of seafoam in the tank. If it is a clogged filter in the tank that will usually clean it enough so it will get better the more you drive it. I have 220 thou on mine and no fuel pump or fuel delivery problems. I seafoam it about twice a year. Put one in the tank, and pour another right down the throttle body until it dies. You have injectors, so take off the power brake line and let the running engine suck it in until it dies. hook the hose back, let it set for about five minutes, and take off. It will look like you are spraying for mosquitos when you take off smoke everywhere as it blows out all the crap that is in there.

 

[rollin2]

Sounds like the filter to me.Should be an inline filter somewhere.

 

[Neck]

There should be a Schroeder valve on the fuel line on top the intake manifold plug a fuel pressure gauge on it and see what you've got for pressure. both running and right after you turn the key on without starting the engine.

 

[WrenchDad]

Guys thanks for the input. I havent tried any of your suggestion yet as I cant get it started. I found out that the only filter is in the tank as part of the fuel pump. I will be able to spend some time on it to night. What about the IAC (idle air control )behind the throttle body could this be causing the problem?

 

[hemigremmy]

Check your vent on your gas cap as well, if the vent is clogged it will run until it can't pull any more fuel and that's it. Once it sets for a minute it could draw some air into the tank and allow it to get fuel again and start back up. I had a car one time that did the same thing. Once you get it restarted and if it dies again just unscrew the gas cap and listen to see if you hear it sucking air into the tank.

 

[cheezy1]

Save your self some trouble and lift the bed off when you change out the assembly...dealer trick. Saves alot of time and draining the tank. Those trucks on average get that kinda fuel milage.:thumbsup:

 

[WrenchDad]

I thought of that also but I didnt know of any reason it should be plugged so I didnt check. Like I said now it wont start. wont even pop or sputter. after cranking I pulled the gas cap and didnt here any thing (just tried it ). I cant hear the pump come on and pressure up when I turn the key so I'm assuming it's either wiring or the pump. Any fuses or relays assotiated with the fuel I've checked (under the hood and the fuse panel in the cab ) and none are blown unless there is one some where I'm not familiar with.

 

[WrenchDad]

Save your self some trouble and lift the bed off when you change out the assembly...dealer trick. Saves alot of time and draining the tank. Those trucks on average get that kinda fuel milage.

Thats a good idea:thumbsup: my brother replaced his pump on his S-10 and cut a hole in the bed above the tank to do it I like your idea better.

You really think that low of fuel milage is normal for that truck. I mean I'll drive to work and back (eight miles total ) and see the needle drop one mark on the guage. Every now and then my check engine light will come on for a little while (maybe a day ) and then go out. I thought my be O2 sensor or some thing. I know if it's not running the right mix my milage would suffer.

 

[Oldsalt]

Many carburation problems are electrical. Could even be the coil. Hit it with some starting fluid [cold engine only], if it burns off the ether and refuses to continue running it is probably starving for fuel. If it won't fire on the starting fluid it's time to check the spark. Remove a plug wire and stick in a good plug. Lay it on a grounded surface and have some one crank the motor an observe the plug. [Any other method that results in the coil having to jump a long spark, like a quarter inch or so, often results in breakdown of the insulation between the winding inside the coil. That is the #1 cause of coil failure].

 

[cheezy1]

Save your self some trouble and lift the bed off when you change out the assembly...dealer trick. Saves alot of time and draining the tank. Those trucks on average get that kinda fuel milage.

Thats a good idea:thumbsup: my brother replaced his pump on his S-10 and cut a hole in the bed above the tank to do it I like your idea better.

You really think that low of fuel milage is normal for that truck. I mean I'll drive to work and back (eight miles total ) and see the needle drop one mark on the guage. Every now and then my check engine light will come on for a little while (maybe a day ) and then go out. I thought my be O2 sensor or some thing. I know if it's not running the right mix my milage would suffer.

I still have my 98...and fully tunned it gets 11-12mpg. :laugh:. And if you put a fuel gauge on it and its not above at least 29psi. constant..then the pump is weak or filter is partially blocked. Which will effect alot of things. Like I learned years ago..''dont shoot the messenger''. Which means normally when the O2 is off..there is something else causing it. Just something to think about..

 

[WrenchDad]

Many carburation problems are electrical. Could even be the coil. Hit it with some starting fluid [cold engine only], if it burns off the ether and refuses to continue running it is probably starving for fuel. If it won't fire on the starting fluid it's time to check the spark. Remove a plug wire and stick in a good plug. Lay it on a grounded surface and have some one crank the motor an observe the plug. [Any other method that results in the coil having to jump a long spark, like a quarter inch or so, often results in breakdown of the insulation between the winding inside the coil. That is the #1 cause of coil failure].

Would there be any other signs pointing to the coil? I'll try the starter fluid tomorrow after work. All the engine or ignition fuses and relays seem OK and like I said I dont hear the pump comming on so it could possibly be electrical.

 

[cheezy1]

Another note on the milage...If that truck was at the dealership at any point..it probably had the engine module ''flashed''. It was a TSB to stop excessive pinging aka spark knock. It took most the advancement out of the computer for the ignition. After I did that to mine the gas milage dropped to where it is now. It use to get 12-14mpg before that. The bad part is you cannot reverse it.

 

[WrenchDad]

Like I learned years ago..''dont shoot the messenger''. Which means normally when the O2 is off..there is something else causing it. Just something to think about..

I agree, I just dont know where to start there are so many possibilities and all Of you guys have been great with your help. I really appreciate it. I cant tell you how many people I know who change thier O2 sensor just because it shows up on the data scan. I had a Ford F-150 that had 4 of them and they were all reading differant and your right something else was causing them to over or under adjust. So I do know that something else might be the cause but I'm not familiar with Dodges so thats why I'm asking. again thanks for the help.

 

[WrenchDad]

Another note on the milage...If that truck was at the dealership at any point..it probably had the engine module ''flashed''. It was a TSB to stop excessive pinging aka spark knock. It took most the advancement out of the computer for the ignition. After I did that to mine the gas milage dropped to where it is now. It use to get 12-14mpg before that. The bad part is you cannot reverse it.

I remember seeing a sticker on the front grill clip that said "Aurthorized dealer modification" and in box provided it was hand written that said 'reprogramed PC" 6-30-00 Does that sound like what your talking about?

 

[cheezy1]

If your not getting fuel..try this. When you fist turn the key ''on''..you should here the ASD relay kick in...and you should hear the fuel pump. If you do not...then simply put a small carb. clean blast and see if it starts and dies. If it does..your hoisting the bed. Or if you have access to a fuel gauge..just connect it and crank..you should have at least 29psi...if not...its the pump. If all is good..you have other issues...lol.:laugh:. I worked at a Dealer doing engines and drivability for years. And my brother spent 21 years at one. So if it is something odd..Im sure I can help ya or at least give ya some ideas. Good luck:thumbsup:
And it could be the mod..I cant remember the number off hand. They had alot of flashes for those model years.

 

[Mark G]

I have a 1999 Dodge Ram 1500 4X4. 318 magnum automatic. Here's the problem first I get terrible gas milage 8-10 miles........
I could use any help you have, thanks in advance.



Kirk

Those trucks on average get that kinda fuel milage.:thumbsup:

Another note on the milage...If that truck was at the dealership at any point..it probably had the engine module ''flashed''. It was a TSB to stop excessive pinging aka spark knock. It took most the advancement out of the computer for the ignition. After I did that to mine the gas milage dropped to where it is now. It use to get 12-14mpg before that. The bad part is you cannot reverse it.

[/QUOTE]


Do yourself a favor and get rid of it:hammer:
Every Mopar I have owned (including the one I bought brand new) has left me on the side of the road. Even other peoples Dodges have left me stranded:glare:
I had the dealer "flash" my truck back in 2001 as part of some other work. He said it was due for a recall, didn't say it would affect anything. It used to get 14-18 MPG but then it dropped down to 10, highway or city. The clown at the dealer told me it was to improve emissions, and was better for the environment. I said, "how is burning MORE fuel and having less power better for the environment?"
I like the look of some Mopars, but the build quality is just terrible.......

 

[hemigremmy]

My brother has a dodge regular cab, 4WD, with a 318 or a 360 in it and he gets the same milage as you. Doesn't matter if he is just driving the truck or pulling a loaded down trailer, same milage either way. He figured out how to get better milage though, he bought a different truck!

 

[WrenchDad]

Do yourself a favor and get rid of it:hammer:
I like the look of some Mopars, but the build quality is just terrible.......[/QUOTE]

I hear ya!!!! I think thats the route I'm gonna take but I got to get it fixed first . Around here (Pittsburgh area) "Wont start and needs work" means your resale value just went down. People around here would expect me to give it to them and then tow it to thier place.
I bought it used private party because I needed a full size truck and wanted to try something different. Well whats different is I have no money because of fuel cost and repairs.

 

[toomanytoys]

My 04 quad cab with a 4.7 averages 14-15mpg. If I drive like my dead grandmother I get 15 if I drive with my foot to the floor I get 14. So....

If you don't hear your fuel pump kicking on the pressurize check the fuses, and i'm sure there is a relay in there. Alot of time with Dodges the horn relay and the fuel pump relay is the same, swap them around and see what happens.