Hi all,

My GC has developed a problem that is related to acceleration. At about 2000+ Rpm, it hiccups, almost like it is during an upshift, or like it wants to downshift. Generally, it happens while climbing hills or first starting out from a stop. From time to time, I'll get a check engine light, that goes away after a day or two. I had the codes polled at the autoparts store and they came up with P1391, which is supposed to be a camshaft sensor or a crankshaft sensor problem.

I've checked into it and there may be other things wrong that could point toward the sensors without the sensors actually being bad....like a cracked flexplate or bad wiring. Any advice out there regarding methods of troubleshooting? I'm flat out of money so I don't want to buy things I don't need.

Thanks

 

Ck all your wiring 1st before replacing any parts. If you have an 3.3 engine the pig tail connector sometimes rub on the water tube or the bell housing of the transmission.

 

Good luck with your problem. I currently have the same problem happening at the same time you stated on a 99 Grand Caravan 3.8 2WD w/ Auto stick.

heres what Ive done with no resolution yet.

1. thought the tranny was going bad - had my tranny guy look at it and he pulled it apart and said it was looking great.

2. Thought it was possible motor mounts, maybe the accelleration was twisting the engine and causing the CV's to pop - replaced all motor mounts, old mounts were dry and cracked pretty bad. No resolution but glad I replaced them.

3. Found the PCV line to the intake was dry rotted and cracked - replaced the 2" rubber line, at first it seemed to fix the problem. every thing just felt better about the van, but no fix.

Thats where Im at now. I think I am going to change spark plugs next because I think and am almost possitive that it is not trans related but a miss fire of somekind. Thats what makes me want to do the plugs next.

Ive always worked on my own vehicles and always figured out and worked through problems but this van is killing me. I would hate to drop it off at the Dealer due to the cost's that would be associated with it.

besides these problems, I actually like the van. its roomy and works well on long trips. we just dove this van ( with the problem) across country from California to Florida and besides doing that "miss fire" thing we averaged 25 mpg.

Well sorry for being long winded but this is erking me to and can't wait to figure out the solution. by the way we just turned 85k on the odometer. If you figure this out please contact me at ibnmiller@gmail.com or please post your solution.

 

Fighting this one myself on a 2000 Grand Caravan 3.8l. After over one year, found yesterday that the flexplate, which looked great from visual inspection, had cracked all the way around the hub behind the spacer, rotated a few degrees and locked up again enough to run another 10,000 miles. Symptoms: sluggish on acceleration from stop or uphill, intermittent ignition dropout on acceleration, intermittent P1391 code/check engine light. Had the transmission overhauled several months back and specifically asked him to look at the flexplate. He said it appeared good from a face on inspection. I wish I would have asked him to remove it and look at the hub... Hope this helps someone out there.

 

Did you ever find a solution? I have almost the same problem.

I have had the following replaced:

Crank, Cam, O2, Throttle Position Sensors, Flex Plate, Plugs, Wiring, Transmission Tested and still having bad hesitation problems. Seems that when it starts acting bad, I can take battery off for about 10 Minutes and it seems to clear the computer, then works better a couple days.

Any help is appreciated.

Thanks

 

I'm having the same symptoms on my 2000 DGC 3.8l 2WD. I dropped almost $1k to replace the flexplate because the mechanic assured me that had to be the issue, but it still acts the same (he told me it was, in fact, cracked but didn't show me the old part). My wife will be out of town for the next few weeks and I'm trying to decide if I should just have the transmission rebuilt. It has about 115K on the original transmission. Any help would be appreciated.

 

This is also the symptom of a slipping tranny, dirty or worn throttle body, valve problem, vaccum leak, wiring or ECM issue, fuel pump, and injector problem.

My bet would be on something with throttle body or valves, most tranny slip causes throw ob2 codes. Wiring would throw ob2 codes and produce other problems as would injectors. Valve issues are the most expensive or labor intensive, injectors are probably second most expensive and labor intensive($80+ each), wiring would be third if you have to trace or tear open main wiring loom.

You have to use process of elimination, the smart way is with diagnostic tools and no investments first. If no OB2 codes it's probably valves. I don't know what causes fuel pump codes so maybe it too.. I don't think standard or ABS braking systems can cause this, they at most cause changing brake pressure do to air in lines, bad pads, or faulty ABS sensor..

It'd be nice to know what it was are what things fixed it when you do get it done.

 

Thanks for the ideas. If I figure it out I'll post my results.