Ok so I don't have a lot of mechanical knowledge. I'm having the following issues with my '92 3.9 liter. I got the truck last fall and when winter came I started having difficulty starting it when it was below 20 degrees outside. It would start and then die after a few seconds. You could give it gas to keep it running but it RPMS wouldn't go up, it would idle really poorly and backfire.

Eventually it started doing this all the time even when it got warm out. You can keep giving it gas for a while and re-start it after it dies and after several minutes it will run. Then after it's warmed up it would start and run okay for a while. It has also started cutting out or jerking at a certain RPM, like 2000. I changed the rotor cap & the plugs with no change.

Today I was messing around with the EGR and tried starting it with a sensor unplugged. Bam started right up. Plugged it back in - rough starting. Unplugged again - started right up. It still stuttered some at around 2K RPM's and almost cut out completely while going down the road. I know the EGR is metal, but I'm unsure about the sensor and plastic disk piece that it's connected to. Is it an EGR sensor? And does any of this make sense?

Here's what I unplugged


Thanks for any help.

Oh also, I've found several threads online about people having similar issues. The problem is that everyone seems to have different solutions. People say IAC, O2 sensors, TPMS, EGR, Crank position sensor, grounds, fuel pump, etc. My wife is going to kill me if I have to constantly dump money into this not knowing what the problem is.

That is the vacuum solenoid for the egr, and I only see 1 vacuum line attached to it. Did you remove them or were they never there? There should be 3 lines attached to it...

See if you can find another 92 with 3.9 V6 and look under the hood. The previous owner of your truck may have fiddled with or disconnected something. As Dodge4lyfe says, all those vacuum connections/lines are there for a reason. Looking at another truck/engine can help you figure out if something is missing/disconnected. I'm fuzzy on the exact operation of the EGR valve/system, but remember that it means exhaust gas recirculation and came along after everybody got concerned about automobile pollution...ever seen the smog cloud that hangs over LA or Denver? The EGR valve opens/closes to recirculate some of the exhaust gases back into the engine, where it can be completely burned, for less pollution out the tailpipe. The Catalytic convertor serves a similar purpose. Your truck is engineered for all these things to work together in synch, so your running problem may be related to them being out of synch or unconnected somehow.

All three vacuum lines were attached originally. For some reason the truck would start that day with the sensor one unplugged. I don't know if it has anything to do with the starting and stuttering problems.

could be a bad sensor. with it unplugged the computer was probly filling in the replacement codes for it, like it does for the o2 sensor