whatnow

I have a 1984 dodge d150 and I am having trouble keeping it running. The truck has a 318 motor with a 4 speed manual tranny. I can start the truck and let it idle for about 20 to 30 minutes and then it dies. When I try to restart it it just turns over. I have already had the carb rebuilt. I have replaced the iginition coil, has a new pick up coil, new fuel filter and pump, cleaned the EGR valve, and even dropped and cleaned the gas tank. I am at wits end with this truck, but I really need to figure it out. Any help would be greatly appeciated. Thanks

blue 68 gts

Sounds like vapor lock

whatnow

Ill check that and get back to you let you know any other ideas if this don't work. thanks

old tired rebel

Do you have the lean burn system on it?

Crazy4Carz.Com

Some easy things to check:

First if you have (1) Spark, (2) air, (3) fuel, it will run.

Air: You are typing this and can breathe so I am guessing we have sufficient air.

Spark: Pull any spark plug wire. It doesn't matter which one. Put an old plug in the end of the wire and ground it against anything metal. Have someone crank the engine and watch for a spark. Gotta spark?
Yes? Ok move on to the next step.
No? Then it is an ignition problem. Possible problems, Points, over heated coil (even though it is new it could still be bad) Ballast resistor, anything in the electrical system.

Fuel: This is an easy one. WITH THE ENGINE NOT RUNNING. Lean over the carb and look down into the throat of the carb and pump the gas linkage. You shoud see the "squrters" spraying fuel down the carb.
Yes? Re-check the other items,
No? Plugged fuel filter, bad fuel pump, bad gas, or (unlikely) clogged sock inside the tank.

Good luck!

whatnow

yes crazy it is getting fuel in the carb. but i will be trying the sparkplug idea you have mentioned. i will let you know how it goes

whatnow

no rebel it does not have the lean burn system

whatnow

well i checked it and its getting spark.

MoparOnly

It's got to be fuel or spark. If it's not vapor lock let's go with spark. I hate to just throw parts at your truck but a new module might do the trick. They're around 30-35 bucks so it's not a huge investment.

whatnow

are you talking about a new ignition control module? I hate throwin parts on too but hey whatever it takes. lol I just really want this thing to stay runnin.

78D200

Does it take the full 20-30 minutes to warm up or does the motor get up to temperature before then, stays at that temperature for "X" amount of time and then dies?

whatnow

It gets up to temp before and runs "X" amount of minutes and then dies.

MoparOnly

Mopar calls them ECU's not modules, sorry about that. They're vulnerable to heat and this may, repeat, may be the answer. You can step up to an orange ECU for 45-50 bucks from any number of vendors online or buy one at a swap meet like I saw last weekend for 30. Stock units are at any parts store but around here they don't want to stock them anymore.
With a new coil and new fuel pump this sounds like the next logical step but I'd sure want to check for spark right after it dies before I'd spend the bucks.

whatnow

yeah we checked the spark right after it died. we had good spark. im thinking the fuel pump is too small. when I got the truck I didnt realize that the person that owned it before had switched out the mechanical fuel pump for a universal electric pump. im going to do some playin with that. any other tips or advice you guys can throw at me would be greatly appreciated. you guys have been a great help so far. i am actually telling alot of ppl to sign up here.

78D200

You need to find out how much pressure that electric fuel pump is pumping to the carb. Also, is there a pressure regulator between the pump and carb? There are only a handful of reasons why someone would install an electric fuel pump on a carb motor (big power needing a lot of fuel, off-roading, converted to some sort of FI).

I would install a mechanical fuel pump and go from there.

rcknrolfender79

I had a 74 camaro with a 350 (I know its not a mopar but the poor mechanics of a chevy may actually help us out here lmao) in it that was doing almost the exact same thing. Only difference is it would die after idling for about 20 to 30 minutes and then I would find gas leaking out of strange places all over the brand new holley 650 that was on it.... It was vapor lock. I put a spacer plate between the carb and intake to help disipate some of the heat before it got to the carb... and that completely fixed the whole situation. Hope this helps you

whatnow

well got it goin now and it stays running! We moved the fuel pump and added a spacer as rcknolfender79 suggested.runs great. Thanks so much guys. lookin forward to trying to help others on here. thanks again.

RobertR

hi I am having this problem now with my 78 d15o 318 auto i put in a new voltage regulator,new ingnition module, new coil, new distributer new ballast resistor, new carburetor runs great for 20/25 minutes and shuts off, wont start even with starting fluid although it wants too. It was a federal vehicle and on the right side of the manifold it has a plate with 2 bolts in it. Not sure what that is for, but today I notice vapors coming out of it when I tried to start it with the starting fluid while it was hot. I have a gasket on the manifold about a strong 1/4 inch thick. It still looked good so I reused it, now knowing if i can buy another one

RobertR

hi I am having this problem now with my 78 d15o 318 auto i put in a new voltage regulator,new ingnition module, new coil, new distributer new ballast resistor, new carburetor runs great for 20/25 minutes and shuts off, wont start even with starting fluid although it wants too. It was a federal vehicle and on the right side of the manifold it has a plate with 2 bolts in it. Not sure what that is for, but today I notice vapors coming out of it when I tried to start it with the starting fluid while it was hot. I have a gasket on the manifold about a strong 1/4 inch thick. It still looked good so I reused it, now knowing if i can buy another one

I been looking and where the EGR valve would be there is a cover and this is were the vapors were coming out of. I orders a gasket for it, but would this be an issue, maybe it is the problem with shutting the truck off?

Iowan

It sure would be nice if you new guys would stop digging up all the old posts from 6 7 8 years ago and answer your own problem. Nothing has changed, bad gas, e-10 or 15, or to much heat in the carb........

RobertR

Sorry for making you upset, but I used the search feature and this post came up, so I added to it my question