Sorry to create an account and make my first post a plea for help. I live in Osaka and am trying to remotely help my father diagnose problems with his 1981 camperized Dodge Ram Van. (He's in Victoria BC.)

Basic specs:
* 1981 Dodge Ram Van (camperized)
* 225 cubic inch Slant 6
* 3-speed manual with overdrive

When the van is cold it runs mostly ok. It's a bit rough but not terrible. After about 20 minutes when it warms up though everything changes and the van loses all power. If you depress the accelerator it will try to lurch forward but it mostly just backfires through the carb. It won't even lurch if it is on any sort of hill, just backfires through the carb and doesn't move at all.

He's replaced the carb and the fuel filter. Checked and cleaned the distributor cap and the rotor, checked the points. Apparently the contacts were fairly dirty. None of this has helped though, the van still runs poorly and has no power when warm.

Before he spends more time and money trying to fix this, does anyone have an idea what might be going on?

Thank you for reading, please let me know if any further information would be helpful.

 

I'd just be guessing, but does that model have a catalytic converter??

 

I believe it did originally, I'm not sure if it is still on the van or not. I can call and check in a few hours when he wakes up. Is it a likely source of this sort of problem? How would one fix it?

 

When they start to deteriorate, the pieces clog up the exhaust.
Anyway, when was the last time he had a good tune-up?
It could be a timing problem, a spark advance problem, a timing chain issue, or a weak fuel pump -- just to mention a few things.
How many miles does he have on it??

 

My first suspicion would be a worn out fuel pump, or possibly the cam that the fuel pump arm rides on is worn down.

 

Thanks very much for the replies and help.

I gave my father a call a few minutes ago and have a few updates. I'm not sure where the 150cu engine idea came from but apparently it is a 225 cubic inch slant 6.

There was originally a catalytic converter but it had a hole in it so was removed a couple of years ago.

The van has about 90,000 miles on it and was tuned up before their last trip (they drove from Victoria to Winnipeg, about 3000mi round trip.) The van ran well on the trip.

Something else I didn't know about when I started the thread is that apparently the van starts immediately when cold but if warm is very difficult to start.

I mentioned the fuel pump to him and he says the engine is getting lots of fuel so he doesn't think this is an issue. If the fuel pump is going what sort of symptoms would it cause?

He has been told that the distributors on these engines are very touchy and if they are at all "off" then the engine won't run well. Any thoughts on this?

Thanks again for reading!

 

Needs to have the timing of the distributor checked. That should have been part of the tuneup.

 

I agree with the timing being part of the tuneup

couple of questions:
does this dist have vacum advance? (maybe the cans not working)
you said he cleaned the points but did they need to be replaced instead?
(consider an ecu/dist to get away from constantly wearing out breaker points)
you said nothing about condition of plugs or wires??


the slant sixes were pretty much bulletproof man anything you heard was just rumour being spread by bowtie guys

 

Between my father and I, we have owned our share of /6 225 engines from the 70-80s.

A few questions.

- Does either manifold have a leak? Or cracked? Common problem. Had two like that.
- Does the ballast resistor look slightly burnt, discolored, poor contacts, or aged? If warmed up, weird things happen.
- Since this did have a CAT at one time, does an O2 sensor still exist?

Now the real question ... Has the EGR gone bad? This is common with the /6 and is known to cut the power when things heat up or cause a very bad idle.
- Since 1976, the /6 came with EGR. The EGR valve on the slant six engine is located in the back of the engine behind the intake manifold. The valve is attached to the engine block with two bolts and replacing the device is a fairly simple job that you can complete in about an hour. The EGR valve is designed to send the engine exhaust fumes back through the motor to be burned a second time, cutting down on the vehicle's emissions.

- Have your tried the key dance and are able to count the blinking "engine' light for possible engine codes? This was pre-OBDII and into the 80s back then.

A great resource ... slantsix.org/forum/index.php

 

Ignition coil ??