defury

I have had a problem with my 1997 DODGE GRAND CARAVAN LE LWB WAGON. The has a 3.8L engine and has approximately 145,000 miles on it. When I took over the maintenance on this vehicle it seems like the previous person neglected it. Here is some information I typed out to keep everything straight. My information may be incorrect feel free to correct me. I am not an experience mechanic, but have done work on vehicles in the past. Some things I did were just to check the condition of them even if they aren't related to the problem.


Background

The van is bucking or loosing power randomly when you reach 2,000 and over RPM's. This happens in park, neutral, or drive (even in 3 and L) It is the worst going up hills.

Previous maintenance seems non existent since I have found many problems and it seems only serious problems were addressed. The problem I am experiencing has been happening for a long time off and on almost since the person that drives the van purchased the vehicle which doesn't make sense to me. It happens too often to go on long trips or up hills since I can't put a huge load on the engine.


Research

Got codes P1391 crank of cam position sensor and P0403 EGR Solenoid Failure from the the scan tool at the auto part store. Originally the sales associate said it was an EGR Solenoid Failure and Coil Failure, but that isn't what the first code says online. I am a bit confused on that. I did find a bad spark plug wire but haven't replaced it. I cleaned it up and it fired well when tested. I will do a tune up when I address the other issues.

I have looked on many forums, websites, auto parts websites, etc... and this is what I found for possible solutions to the problem

EGR Solenoid, EGR Valve, or whole assembly replacement

Crank or Cam sensor replacement

Timing Chain Slack throwing off the timing

Catalytic converter failure

Vacuum leak

Tune up required (Plugs, Wires, and Coil) and possible coil failure


Troubleshooting

I am not sure if some of these apply from my research.

The catalytic converter doesn't seem to be damaged the exhaust is strong even when idling and from what I have read it would not be if it was damaged. Also they said to tapthe CAT gently and see if you hear anything other the noise from tapping it. It sounded fine.

People on mopar forums stated that with this make and model the timing chain will last the life of the vehicle if the oil was changed properly and not ran low. The van has 146K miles on it so I'm not sure what the end of life would be.

I would think the tune up would be a good thing since it looks like it was never done even if it doesn't fix the problem. The plug wires look OEM to me, but I could be wrong. The plugs look old and worn out. The gaps keep changing on me for some reason.

There is a strong vacuum at the EGR Solenoid exit and Purge Solenoid exit. It will pull my finger in and you can hear it over the engine noise when not trying to plug it. I only ran it for a few seconds to check.

People online said to try to blow air through the EGR solenoid and purge solenoid so I tried that and both didn't let me so they seemed ok. I haven't done resistance or continuity tests yet. I don't have a scan tool to test the EGR solenoid myself and don't want to move the van unless I have to at this point.

I tried plugging the vacuum line past the EGR valve since from my research it seems like it isn't needed except for smog prevention. I could be wrong. I also tried plugging it after the purge solenoid. After everything I tried it didn't make any difference.

I pulled the oxygen sensor that is past the CAT and other than being dirty it was ok in appearance.

Drakovich

I had a similar problem of losing power randomly and sputtering as if it had water in the fuel tank in a 96 dodge caravan until eventualy it would miss on a few cylindars and not even move, scan tool was saying catalytic convererter and lean mixture. Turned out to be a fuel filter wich was located in the fuel pump was getting plugged and needed whole pump replaced. Also did a tune up and after all this runs smoothly altho we wont be putting any more money in the vehicle next time it takes a dump its getting scrapped.

When it doesnt get enough fuel the computer tells it to pump more and when it doesnt see that fuel being burned via O2 sensors etc u get error codes there in all the smog control systems.

mr340

My '06 T&C had the same symptoms with the same codes plus a few other random codes. It would shut down when placed into R. I discovered a bad connection in the sensor ground wire in the main engine harness. You can try grabbing hold of the harness where it "T"'s over the top of the transmission and shake pull push tug and twist it to see if you can cause the symptom to appear. If that works for you, open the harness and find the connection point containing 4 blue wires, check the connection for a loose or broken wire. The factory used hot glue and shrink tube for the connection and it appears that heat from the engine bay causes the glue to break down. I fought this problem for almost a year, and multiple dealers and general mechanics could not find it.

Good luck.

defury

Drakovich and mr340,

Thanks for the response. I will look into both of these before purchasing any parts. I have a technical background and prefer to troubleshoot before purchasing parts to replace. This information is great and I will check everything and get back to you.

Thanks again!

TVLynn

I would clean the throttle body, replace the plugs and wires to start.. If you think the converter is bad? Remove the O2 sensor and drive it to see if it makes any difference. The V6 has a cam chain. Major job to replace it, but it should be fine

blue 68 gts

Sounds like a misfire under load..



Research

If it was a Crank sensor, it wouldn't even start. Cam sensor could possibly be bad. The code you gave for the cam sensor is a manufacture code. You should find a Dodge Dealer or Independent Shop and get more info.




Really can only check with a scan tool on a drive test, checking to make sure the rear o2 ISNT switching like the pre-cat o2, or with a 5 gas




You're fine if it made no noise.




A tune up is always a good idea, especially if it hasn't been done.



Incorrect. The EGR should not be allowing gas into the engine at idle. It should only operate while at a cruising type speed.



You usually need to operate it with vacuum pulses..





It's most definitely needed. It helps keep NOX down (for emissions) and keeps the combustion temperatures down.






You really need to test it either with a scan tool or a Voltmeter.




I hope this helps...

blue 68 gts

Very common failure. One of the most neglected replacement items on a car.



You said two different things here.

Yes, when there is no fuel coming through, the the o2 sensor senses ALOT of OXYGEN, the PCM will try drive the system rich.

The fuel pump over heats itself from trying to push more and more fuel through a restriction (aka here: the fuel filter).

You're more likely to wind up getting a Misfire code over anything, thus, hurting the Cat. Which is also bad.

defury

Blue,

Does this also apply to me? I am not getting any misfire codes, but it seems like a misfire under load problems? Should I address the fuel system? I'm sure its been neglected as well.

I have to try to get my van to my garage which is 25 miles away with large hills. I will probably get a dolly and tow it. I have limited tools where the van is right now.


Thanks again!

Drakovich

A fuel filter never hurts IMO it probably could use it, however I cant tell you for sure that is your problem. If your going to fix the problem no matter what then investing in a new fuel filter and a tune up would be an awesome idea though.