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Followup To
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Followup To
Question -
Hi there i own a 1991 plymouth voyager Le, It is playing up at the moment. When I drive it just stalls on me, sometimes I will get 10km, then at times only 200 metres. Sometimes it starts straight after and other times it wont start for sometime. Any ideas what this could be!
Thanks
Answer -
Hi Adam,
When you respond, let me know if this is a 4 or 6 cyl engine, for now I'll assume it it the 3.0L 6 cyl.
The most common reason for what you describe is that the sensor in the distributor that generates the signal for timing of the spark is going bad, which seems to be provoked by warming up, so it quits after a bit, then recovers after cooling down, etc. You can verify this by doing a fault code readout on the engine controller. Here is a copy of my standard approach. Give it a try and let me know what you determine:
"The causes of shutdown then restarts after cooling:
the photo-optic sensor in the distributor is not working
(that signal is required to be received at the computer for the autoshutdown relay to be closed),
the autoshutdown relay is defective,
the controller (computer) is defective,
or the wiring between them (or the wire from the battery to the autoshutdown relay) is compromised.
I would bet on the photo-optic sensor being the cause.
You can test that out by reading out the fault codes that are stored in the computer:
Turn the ignition key as follows: off-on-off-on-off-on and leave in the on position (where "on" is the normal run position, and do the switching process in less than 5 elapsed seconds). Then watch for the check engine light to begin to flash, pause, flash, pause, etc. Count the number of flashes before each pause and make a mental or written note. The last two groups of flashes will be 5 in each. Then pair up the numbers of flashes in the order they came out in order to form two digit numbers, e.g. the last number so formed will be 55 (which is the code for "readout is completed"). If the first number is "11", (e.g. one flash, pause, one flash, pause,) that means the phot-optic sensor signal is not getting to the computer. Check the electrical disconnect plugs at the distributor and if they are o.k. then I would suggest you buy a new sensor unit.
If you don't have a manual that describes the several steps to disassemble the sensor unit from the distributor, let me know and I'll type it in and post it back to you. If you get anyother numbers let me know about those as well. You can repeat the readout as often as you like so as to verify that you have the correct fault code numbers."
Roland
Tuesday 14th
Hi Roland,
Thank you for your reply to my question. My Plymouth Voyager LE is a 3.3L V6. I tried the fault code readout and this is what I got: flash,pause,flash,flash,pause,flash,pause,flash,flash,flash,flash,flash, pause,flash,pause,flash,pause,flash,flash,flash,flash,flash,pause,flash, flash,flash,flash,flash
Not sure of the number code for this sequence of flashes and pauses. Also does the Van have to be immobile (i.e stalled and not starting) for the correct code to be read?
Appreciate your time,
Look forward to your reply,
Adam
Answer -
Hi Adam,
No, the engine doesn't have to be operable to read the codes. Now as I reviewed your observations I see a pretty clear picture except for one detail, I believe after the fourth pause you should have had two flashes rather than one because the numbers always come out in serial order. What I get as the codes, taking your list as given, is 12,15,11, and 55. The third number has to be 21 (or maybe 31?) for the list to be in serial order. So please recheck and let me know it indeed there are two flashes after the fourth pause, or three, or? I'll assume for the time being that it is two flashes and the code is therefore 21.
The 12 code just means that sometime in the past several months the battery was disconnected, not an important matter. The 15 code however means that the distance sensor is not getting its signal to the controller. That would indicate too that your speedometer/odometer is not working well or at all. Is that the case? If not, that is another reason to check that there are indeed 5 flashes after the third pause. Let me know if the number is other than 5.
Finally, the 21 code I assume is the third number means that the oxygen sensor is not producing an output signal, which suggests that it is either unplugged or worn out. This sensor is mounted on the exhaust manifold and can be changed by the amateur if you have the proper size wrench to remove it. If that were true, that would help to explain why you are having stalls because the fuel mixture is made correct by that sensor. So, let me know about the pause count following the fourth pause, and whether the speedo is working, and see if you can locate the oxygen sensor on the exhaust manifold behind the engine. It looks like a spark plug with wires coming out of its tip. Check to see if it is connected and that the wires look alright and that it is plugged-in properly nearby. It should be located centrally on the manifold on the down pipe that then attaches to the rest of the exhauxt system.
We are making progress!
Roland
Thursday 16th
Hi Roland, thanks for your information, I checked the flashes and pauses and there are two after the 4th pause. Some of the pauses vary slightly in length. So I guess the code is: 12, 15, 21, 55. I had noticed that the speedomoter was not working one time I drove. I located the oxygen sensor and checked the wiring and connections, they seemed good. Do you think the oxygen sensor is worn out? I thought it could be the fuel pump playing up, could this be the case? Also the problem with the speedomoter, is it easily fixed?
Hopefully getting to the bottom of it!
Thanks again,
Adam
AnswerHi Adam,
The oxygen sensor is likely to be worn out based on the readout and the fact that the wires seem o.k., and that is consistent too with the engine stalling (at least that is one possible cause, but I can't guarantee that will make everything right.) The challenge to replacing it is mainly getting it to release its threads so you can unscrew it. You may want to put some penetrating fluid around the threads for a day or so before you first try it and be sure to use a properly-sized box end wrench (generally a 22 mm) so as not to round-off the flats. It may help to have run the engine to warm up the exhaust just before you then remove it. But be careful not to burn yourself on the hot exhaust. Putting it in is the reverse: there will likely be some anti-seize compound on the threads or in a capsule to apply to the threads so again in the future it can be removed. There also will likely be a gasket to seal the joint. The important technique issue is the be very gentle with the wires that extend from the top of the sensor so as not to damage them or the sensor. You are supposed to torque these sensors to to 20 ft-lbs, but it is quite difficult to put a socket wrench on the sensor without damaging the wires (they do sell sockets with a slot so you can run the wires out the slot and then apply the socket to the sensor, but these are expensive. If the electrical connector will fit thru the opening of the 22 mm box (or open end wrench) I would forget about doing a torque measurement, just tighten it about as you would a spark plug, using the open or box end-type of wrench rather than a socket. Hook up the electrical plug and your are done. The code will not self-erase for maybe 50-100 key cycles (unless you disconnect the battery for 5 minutes or more) so don't be surprised to still get a 21 code even after the sensor is changed. But check it later and see that it is no longer present.
On the 15, if the speedo is working releably now, then the reason for the code is the one time that you saw it acting up and that set the code. I wouldn't pursue changing the gear on the distance sensor unless it begins to act up once more. It is easy to replace, a single bolt, and if the gear is why it is flakey then that is not too expensive. An entire new sensor might be close to $100. So do the O2 sensor and see how things go after that.
Roland
