Hello, I have a 1998 Dodge Ram 1500 4x4 automatic with the 5.9l V8 Magnum engine. I am currently having sputtering and stalling issues, but before I get into details of the issue I'll start at the beginning.

About a year and a half ago my friend recieved the truck from his uncle because it died on him one day and he did not feel like messing with it. Well when we got it, it would crank over but not fire. We ended up doing a complete tune up on the truck and then some.
New:
plugs
wires
cap
rotor
ignition coil
crank sensor
valve cover gaskets (done later)

At this point the truck still would not fire over. Turns out the cat was clogged. So we cut the cat off, hollowed it out, and then clamped it back on. The truck ran great after that for about 8 or 9 months before the transmission started acting up on it and I bought it from him. The truck pretty much sat over the winter because I did not have a garage to work on it in, but when springtime came around I pulled the transmission out and found a used Jasper rebuild with aftermarket torque converter for it. Instead of trying to reinstall it myself I took it to a local garage and had them put it back in for me.

After getting the truck back from the garage everything seemed to be good, it shifts fine and was running fine, until I started driving it longer. I noticed that after driving it for awhile it wuld start to sputter and if I slowed down or stopped it would drop the rpms, idle rough, and eventually shut off and if I pushed the gas pedal to try and stop it from stallling it would pick up, but hesitate alot before doing so and when it picked up the rpms it would backfire and after I stopped it would shut off shortly there after. My oil level is fine, oil pressure looks good, engine temp is good, and coolant level is full.

I did try swapping out the IACV with the one off of the spare engine I have for the truck but that just seems to make it act up quicker. However I did notice that when it starts to act up I can hear the throttle body sucking in a lot of air and it around the IACV. I did drive the truck later with the IACV unplugged and it seemed to run better but still evetually shut off (no loud sucking noise though). I know it is currently throwing a code for the O2 bank 1 (high voltage) but I was told that could be due to improper fuel mixture.

Any advice of what to do would be great. Thank you in advance.

 

Have you checked the fuel pressure to see if its were it should be ?. Also check the throttle position sensor and the map sensor. Any of these parts going bad can cause the problems your having.

 

Did you change the pre-cat O2 sensor when you gutted the cat? If not, unplug it and see if it runs better.
Remove the throttle body and make sure the well the IAC sits in is clean. With throttle body off, look inside the manifold and check for pooling oil towards the rear. If you see oil, time to replace the plenum gasket.

 

Did you fix the plenum? Have you looked at your plugs again lately? Did the shop that installed the trans damage the crank sensor?

 

Ok I will try pulling the O2 sensor and checking the plenum today.

Also not sure if it's important, but whenever the truck starts to act up and the RPMs fluctuate all the lights in the truck will flicker. They dim and then come back. I figured that was due to the alternator not spinning as quickly but thought I would mention it anyway.

I'll let you guys know what I find out. Thanks.

 

Check your battery cables, major connections, and all grounds. These trucks are REALLY sensitive to such issues.

 

Ok, I will check that too, another thing that might be important to note. The truck has an aftermarket alarm/remote start system. Could that cause problems?

 

I think the alarms are an all or nothing affair, it will either run, or it won't, no in between.

 

I just took the throttle body off and shined a light down into the intake and I can see a small pool of oil in the back so looks like the gasket went bad, so I'll be replacing that in the next couple days. Is there anything else that I should be on the look out for with the gasket being bad? Other than checking the plugs and cleaning them if necessary.

 

If your going pull the intake manifold to fix it, look at the Hughes plenum plate upgrade, if you just replace the gasket and use the stock plenum plate, its just a matter of time before it blows again.


You might also want to do the kegger mod while you have it a part. You can read about it at the top of the forum page.