93 voyager 3.3 od hesitant bucks, shifts, dies

[Voyagenot]

I bought the van from a lady who has chased this problem for years. She spent $5000 on new trans, alt, fuel pump, plug wires, trans module, ab relay etc. The van starts and runs great, at any speed it bucks like it wants to downshift with no pedal movement. It does this in od and third, but it is more constant bucking in od. If you depress the pedal hard, sometimes it dies, and it will restart in neutral while still rolling. I read a thread that suggested the input speed sensor so I replaced the input and output speed sensor, with no change. While I am waiting for comments, I will go through the former owners reciepts, and write down all the stuff she had done.

She also cleaned out the throttle body and bought a coil. She replaced the cam and crank sensors.

[taillight]

Are there any trouble codes ?

[Voyagenot]

Originally Posted by taillight

Are there any trouble codes ?

I am a little hesitant to go get the codes read and spend money for the service. I have receipts from the former owner and she repeatedly had the codes read at $49.95 a pop and she has had the crank sensor, for example, replaced twice at $150.00 parts and labor. I went to autozone for a free read and they said they only go back to 1996.

I think that the output speed sensor that I installed yesterday is a cheesy aftermarket variety because the hesitating is more pronounced since the install. The hesitation is almost a throttle hesitation instead of a transmission bucking, A bucking which is still there. If I give the vehicle lots of throttle while going twenty in OD, it bucks severely three times before downshifting----sometimes. Sometimes it downshifts and accelerates fine, and sometimes it dies and needs to be restarted.

In reading her old invoices, each code read has led to a replacement of the AB relay, cam and crank sensors, TCM, Auto Shutdown, Fuel Pump, Alternator, repairing of the main wiring harness to power up the PCM, and I replaced the speed sensors.

It sounds like this problem is being chased around in a circle

[taillight]

You can read your own codes. Turn the ignition key on and off 3 times and leave it on the last time. Count the number of flashes on the check engine light watch the flashes and spaces. You will get numbers like 23, 54, or something like that. Put the old speed sensor back in. I have had a few 3.0 l Dodge engines that did this because of the O2 sensor and I noticed you did not say O2 replaced.

[Voyagenot]

Originally Posted by taillight

You can read your own codes. Turn the ignition key on and off 3 times and leave it on the last time. Count the number of flashes on the check engine light watch the flashes and spaces. You will get numbers like 23, 54, or something like that. Put the old speed sensor back in. I have had a few 3.0 l Dodge engines that did this because of the O2 sensor and I noticed you did not say O2 replaced.

I CHECKED THE codes using the ignition switch and I got 12,21,55. This makes sense because I did dissconnect the terminal to reset the computer last week, and 21 refers to the O2 sensor. I also cleaned and replaced the old output speed sensor and the van runs real smooth with the occasional hesitation while accelerating, a little worse with hard acceleration. The dying of the whole van that takes place sometimes with hard acceleration has not happened but that is a every 100 miles thing. I am still worried that it is a sensor upstream from the o2 sensor that is causing this code and I have my doubts that replacing the O2 sensor will fix the problem. Thanks for the tip about the code check, I read about in different posts but it is easier then it sounds.

[RIP]

Not a sure thing but, changing the O2 sensor will probably fix your problem. Check connections and wiring first. It's not a scheduled component change on most cars yet but, there is a growing consensous to change O2 sensors at regular intervals. For your van it would be every 60-80K miles. That applies especially to upstream sensors because they take the most punishment. Recommend the pre-assembled type and not those that come with a universal connector you have to crimp on.

[Voyagenot]

Originally Posted by RIP

Not a sure thing but, changing the O2 sensor will probably fix your problem. Check connections and wiring first. It's not a scheduled component change on most cars yet but, there is a growing consensous to change O2 sensors at regular intervals. For your van it would be every 60-80K miles. That applies especially to upstream sensors because they take the most punishment. Recommend the pre-assembled type and not those that come with a universal connector you have to crimp on.

Problem solved and I can't believe it. I pulled off the O2 sensor and there was a broken wire that had been spliced at one time, probably when they broke it dropping the tranny and the splice was pulled apart. I put in the new one anyway and the van runs as smooth as a babys bottom. Very cool and thanks for all the help.

[RIP]

You fixed it and you posted the fix here. You are the man!