Question for the Dodge gasser guys.

[moparguy]

The truck; 89 3/4 ton with 318 and throttle body injection, automatic, lots of miles, the classic ugly farm truck.



Symptoms: it runs great about 1 out of 20 drives, the rest of the time it does the following in combination, or sometimes just one symptom. 1. Runs as thought hitting on 5 or 6 cylinders. 2. Give it fuel and it just like you tuned the key off, then it's back on with a jerk to the drive train. When this happens, drive like you had a egg under the accelerator pedal and it's not too bad.



What I've done over the past few months.



Changed TPS, no help.

Changed plugs, wires, cap and rotor, and coil, no help.

Unplugged, cleaned and replugged all connections I can find under the hood. No help.





All suggestions welcome.



Thanks, RJR

 

[catoiler]

Fuel filter,coil

 

[Philip]

Pull the distrubitor and check it for side play. I have seen many Dodge dist go bad in this way. If you want a faster check method. Pull the cap and rotor. Look at the 8 sided star under the rotor. If it looks shiney on the ends of the star points. They have been touching the pickup assy. Replace the dist assy.

 

[CFast]

Bad cat convertor, or bad egr valve? EGR is easy, disconnect the vaccum line and see if it runs better.

 

[moparguy]

No cat, the distributor appears to be ok, and the PVC valve is good. I'm thinking something electrical, and then perhaps a sensor, or computer type problem.



The frustrating thing is it sometimes runs great.

 

[michigandon]

convert it to carb!

 

[Philip]

Hook a old style dwell meter up and go for a drive. If you see the dwell drop very much or go to 0 then it is a pickup going bad or the dist like I posted earlyer.



If you can get a hold of a O scope that would work also.

 

[rbattelle]

Major vaccume leak?

 

[B.G. Smith]

I have an 89 Ramcharger, 187,000 miles, only thing I would bet on is that mine is uglier than yours. I have had some trouble with mine over the years cutting off, usually at a red light and wouldn't re-start until you turned the key all the way off then back on. It has a switch built into the oil pressure switch that turns the fuel pump on, I guess at idle the pressure got low enough to cut the pump off. Also had to replace the MAP sensor but it completely quit when it was bad. Also, you might want to check the big bulkhead fitting where all the wires go through the firewall on the drivers side, I had a bad connection there too. Good luck. bg

 

[CFast]

Try pulling the EGR vaccum line? My buddy had a toyota 4 banger act similar, the EGR stuck.

 

[moparguy]

,LOL, BG we may have to post photos to see who has the ugliest rig. I'm gonna change out the oil pressure sending unit to see if that changes anything.



I did disconnect and replug the bulkhead connector, everything appeared to be OK.



Philip, I'll see if I can come up with a old dwell meter.

 

[EBottema]

I have one question for anyone looking to buy a Dodge gasser... . Why when you can get a Cummins????

 

[moparguy]

Good question, however we have two CTDs, my 95 and the CFOs 98 12V, the 89 is the traditional farm truck, used to go down the muddy gravel roads, haul fire wood, pull extra hay trailers and in general beat around in.

 

[EBottema]

Hey... Sometimes gas are better than diesels i can agree with that... The question wasn't directed as a flame or anything, I just couldnt imagine something going to the dodge dealer and buying a Semi "fake" hemi over a cummins



Erik

 

[Eric_77]

sounds like maybe cam timing but unsure why it would work fine sometimes.

 

[SGibson]

sounds like a pick up or reluctor of course it could be something as simple as fuel filter,pump or ballast resistor at least they are all cheap&easy, my 88 1ton w360 acts similar, but my problem is the quadrajunk,i'm going to take that carb off w/ my 10ga. one of these days.

 

[Hohn]

My bet is the fuel filter. Why?



When the fuel filter is plugged, it can cause a lean condition as the throttle is opened. There is an "idle circuit" and there's the other circuits, just a like a carburetor. Once the first part of the transition is made, it will smooth out.



A stumble just off idle is usually a fuel problem.



Justin