I have a 1984 W150 that I have been trying to get back on the road for awhile now. After taking it to two garages and changing about every part in the brake system, it will stop again. But now I can't keep it running. After the engine warms up, it stalls and will not restart. I typically use the truck to plow my driveway and to get to work in bad weather. It spends a lot of time sitting. I am trying to fix this myself due to amount I just spent on the brakes.

What happens is this. It will start when the engine is cold then, after it warms up, it sounds like it is running on 7 cylinders. Kind of a vibration, just doesn't seem like it is running smooth. At this point if I put it in gear it stalls, I can move it a little in the driveway but forget going up a hill. If I leave it sit and idle for a long time and it will keep running. When it is acting like this, if I press the gas down quick it coughs and hesitates before it will rev up. If I put my hand over the air intake it responds better to a quick push on the gas peddal. After it stalls it will not turn over, it acts like the battery is dead but the radio does not reset and the lights stay on. If I leave it sit for a while it will start again.

I have tried the following things: I replaced the air/fuel filters, changed the cap and rotor, tested the battery and alternator voltage, pulled the plugs and looked at them, cleaned the carb's fuel inlet valve, rebuilt the whole carborator (I found a Tablespoon amount of black non-metalic flakes in it, most of this was at the bowl vent valve.), repaired vacuum line that I broke taking the carborator off, checked the ground from battery to chassis.

What should I try next?


2. Another problem that I have had since I got this truck a few years back is that after it sits for awhile (days/weeks) it cranks a really long time before it will start. It often goes until the battery is about done and then fires off and runs. The truck will typically restart easily if has been run recently (within hours). Before the above problem, it always has run once I got it started.

Any ideas why this would be?

1984 Dodge W150 318 Holly 2280 4X4 Plow.

 

what is the gap like on the spark plugs? the idle speed could been incorrect and be causing it to stall. 1 more thing that crosses my mind is the timing. the timing not being right can also cause it to stall when you step on the gas.

 

Replace the plugs and gap them to .35 its a cheap fix that fixed my bogging issue in under 20 min. ( dont buy any bosch or platinum crap, good ole champion coppers )

Also, did you spritz water on the plug wires at night? You may have a plug wire that is arching under load. Plug wires are another cheap upgrade since you already replaced the cap and rotor.

Check your vacuum advance. The hose could be cracked or something and not be allowing the distributor to advance the timing under load.

Also, if your accelerator pump is bad inside the carb you can slowly accelerate but not quickly.

Good luck man, I just spent the past two months getting my truck running. I have the same year and everything just a few more minor issues with mine too.

PS I rebuilt my ENTIRE brake system so I feel your pain on the money thing. Luckily I did everything myself minus the second master cyl I had to install. ( first one was bad from the factory and after taking it somewhere to have them power bleed they told me that it was a bad master. At that point I just paid the $200 to get it fixed and on the road. lol )

 

Thanks for the ideas. I will get a chance to try them soon and see how it works.

How does one check the vacuum advance on the distributor?

 

You can check the vacuum advance for leaks by sucking on the hose. If you keep getting air it is bad. You should be able to pull a vacuum on it and seal the hose with your tongue. The vacuum should hold the hose to your tongue; if not it has a slow leak and failure is imminent. Be sure of course that the hose does not leak.

 

I'll try that, if I have the distributer cap off will I be able to see the rotor move when I pull a vacuum on the line?

I changed four spark plugs on the one side last night then ran it a bit. Seemed like the ones I took out had a little bigger gap. Maybe .050 instead of .035. I tried to adjust the fuel/air needle in the carburator base but am not sure if I did it well. It seems like I just run it in and out and it doesn't do anything and then the engine will begin to stall. At one point I had the one side turned all the way in and it was idling along like nothing happened? I checked that the fuel squirts into the carborator when the throttle is pushed and it does.

It would idle and back in and out of the garage. If I tried to drive up the hill by the barn it would quit on me...

Right now the engine acts like it needs to be partially choked to run right. I don't know how to test this thoery when I am in the cab trying to drive it though. It will idle but if I jab the throttle it will bog down and them back fire out the carburator. But if I put the choke part way closed it will rev up okay...

I wonder about the vacuum in the manifold under the carburator. I noticed that when the engine in bogging down the vacuum actuator on the choke plate comes out then back in when the engine comes back to idle. Loss of intake manifold vacuum causing the problem or is this just a symptom of the engine slowing down and trying to stall on me?

If I need to block the air going into the carb to get it to run right, what does that mean?

 

the back fire makes it sound like it is a timing problem. i would have to guess that you would have to adjust the distributor to compensate for the slack in the timing chain. i would adjust the carb to about where it should be then start messing with the timing.

 

Plugs burn open and points burn closed. This is an old fact that means the gap gets bigger on plugs as the electrode burns down and point gap gets closer as material builds up on the contacts as they are used.

"I'll try that, if I have the distributer cap off will I be able to see the rotor move when I pull a vacuum on the line?" The answer is no. When the vacuum advance works it moves the plate that holds the points, or whatever electronics are mounted to that plate, not the rotor. You should be able to see the plate rotate slightly.

"If I need to block the air going into the carb to get it to run right, what does that mean?" It means you are running lean. If someone has tightened the adjusting screws to hard into their seats the needle and/or the seats can be damaged and then will not regulate the fuel properly. I can't say if this is your problem just that it can happen.

Change the other 4 plugs first. I agree with crazzywolfie that it sounds like timing. A vacuum gauge will pay for itself the first time you use it. I highly suggest you use one to find out what is going on in the engine.

 

NO, the rotor will not change position when the vacuum advance is actuated. The Vacuum advance will rotate the plate that the points or electrical pick-up is mounted on.

Your vacuum will drop when the throttle is opened so the movement on the choke actuator may be normal.

I am guessing that you have a plugged jet in the carburetor that is not allowing the fuel to come in fast enough to support more RPMs.

I am certainly not an expert but I tend to disagree with Crazzywolfie on it being timing. I think a lean mixture could cause the backfire. I think the fact that it runs while cold when the choke is on really points to a fuel problem.

You said the truck spends a lot of time just setting……..that can cause stale gas and varnish build up. You may want to run gas stabilizer in the future to help prevent gas problems.

I just re-read your original post……..you rebuilt the carburetor. Could it still have a plugged jet? Or could it have re-plugged from gunk in the fuel line. I have problems with a Suzuki Samurai and a mechanic said to put Sea Foam gas additive in the gas. Sometimes it seems to help. Where your Dodge will idle you may try to add some and let it run and idle to see if it will dissolve some crud in the carburetor.

Next item….. Have you checked the fuel pump pressure and volume? Maybe the pump is not delivering enough fuel.

At the end of your first post you mentioned the slow starting after sitting for a while. That is often from an absence of fuel in the carburetor. It either evaporates or leaks out and the fuel pump has to run long enough to pump gas back into the carburetor. If the pump is weak it will take longer to do this.

Crazzywolfie mentioned slack in the timing chain. I can tell you a horror story about the timing chain on my 1977 W150 that was all about spending more and more money. When these rigs with a factory plastic timing gear get age or miles on them replace them before you have to tow and fix.

 

the fact that the truck back fired through the carb and he has to have the scews on the carb adjusted all the way in just to keep it idleing is what makes me beleive it is a timing problem. playing around with the timing is simple and can affect weether it idles or stalls. all you have to do is loosen the clap on the bottem of the distributor a tiny bit till you can rotate it.