QuestionHello,
I'm working on a 1995 chryler Town&Country 3.8L mini-van. Over the years, I have made extensive repairs to the 3.8 engine, and had an opportunity to replace the loud-clicking and leaky 3.8 with a good running 3.3L engine from a 1993 Plymouth Grand Caravan. The 3.8L had developed a water leak, opposite side of the water pump. The water pump housing, or the plate that the pump bolts to, has a hole, where 15 years of corosion "ate" through the metal. Instead of trying to fix that "hard to even see, much less to get to problem", I decided, I had spent more than enough time and money in trying to keep that engine reliable. A co-worker was selling his slightly beat-up '93 Plymouth van, and the 3.3L in it looked very identical to the 3.8L in my van, so I bought it for a $150, with intentions of using the motor in my van. Here I am now, after working on it for the last couple of months, unable to get the 3.3L to "fire-up". Everything bolted-up the same, as far as transmission, and motor mounts. I used my 3.8L upper intake manifold/carb, because the wiring harness on that particular side of the engine has a few more sensor plugs/sockets for the carb. I also had to use the rear exhaust manifold, due to it having a small pipe that comes from it, and bolts-up to the intake. I used my 3.8L camshaft sensor, due to the wiring plug-ins being different from the wiring plug-ins on the 3.3L. After hooking every sensor and vacuum line back up, I turned the ignition, and the starter turns the motor, but the 3.3 is not firing. I had previously and continued to bleed the fuel rail assembly each time I switched or changed it. I made sure that the gas was pressurized before trying to start the motor. I switched out the computer modules, fuel rail assemblies with the fuel injector/coil-pack/camshaft sensor/temperature wiring harnesses, and the motor still would not fire. I did notice that the primary plug-ins, located under the battery tray, were a little different between the 3.8 and 3.3. There is a difference of "pins" inside the plug-in sockets, one of the 3.3L plugs has a pin missing, or not being used, and the other big plug on the 3.3 has an extra pin, or something to that effect, when compared to the 3.8 wiring plugs. The male/female sockets will plug into each other with no problem. I even bought a new 3.3L camshaft sensor, and tried it with the 3.3 wiring harness on that side of the motor, and still no fire. I continued to try diferent variations such as: switching computers/ wiring harnesses, etc. The only wiring harness that I have not tried switching, is the other major one(aternator/oxygen sensor/intake/carb sensor wiring), at the rear side of the motor. If I swithed that one, it would involve using the 3.3L intake and rear exhaust, and splicing the main hot wire coming from the alternator. I don't know if that would make a difference, but could/would try it, if need be. I checked all fuses, and they all seem to be fine. I checked the 3.8's computer trouble codes and they were: 12, and then 55. When I first checked the 3.3's computer trouble codes, they were 12, 21 or 22, which ever one means engine not getting hot enough, and then code 11, which means ignition reference failure, and then 55. After doing other switches with the wiring harnesses as previously mentioned, both computers displayed only codes 12 and 55, but the 3.3 engine still has no fire. I even spliced in the 3.3 camshaft sensor wiring to the 3.8 wiring on that part of the wiring harness(the wires are color coded and matched each other), but the motor still will not fire. I am starting to suspect a difference in the wiring as being the cause of the 3.3 not firing, or at least hoping that is the cause, and there is a simple fix or modification that I can do. I have thought that maybe, the computer(s), which ever one, would be required, may need to be programmed for that particular engine and/or wiring system. I just don't know! I have seached on the internet, but have been unable to find any info. on this particular engine swap. I have dug pretty deep, but I know, only a couple of hours of searching forums, is not really digging deep enough. If you know what I need to do, to get the 3.3 to fire, PLEASE help me with any info. or advice. If you don't know, could you help me search, or refer me, or my 3.8L to 3.3L problem(s) to other(s), who may be able to help me? I don't really want to fix that 3.8L engine, or try to find another 3.8L, as I have already invested so much time with installing the 3.3L, and I am very tired physically and mentally from the whole experience. I have an old barn, as my only shelter, and it has been very COLD, working outside on this project!
I will do whatever I must to get my van back on the road, hopefully, at some point in the near future. While waiting for a response, and due to the Christmas holiday delaying a response, I may try changing or switching out that other wiring harness/3.3 intake/exhaust, to see if that makes any diference, as I will be off from work for Christmas 'till Jan. 3, 2006. Oh yeah, in case it matters, I failed to mention that my '95 has a main fuse block under the hood on the driver side firewall/fender, the '93 did not have any such fuse block under it's hood, or at least I could not find one under the hood. This is why I suspect a difference in the over-all wiring as the cause of incompatibillity with the 3.3 not firing. I just hope I can make the 3.3L work, as it was a very quite and good running engine, and it was cheap! I did think about the possibillity of changing camshafts, but even if that would work, I would have to probrally buy a new 3.8L cam, as I don't know the extent of the damage to the original, due to that motor clicking very loudly, and pull out the engine, to replace the camshaft. I wish my brother would have took better care of my late mother's pride and joy, she loved that van. From doing prior repairs, and from the look of the inside of the engine's valve covers, intake valley, etc., my brother never changed the oil, and drove it with little oil, as there was evidence of several oil leaks, when I first got the van, a few years ago. The engine was a "sludge" nightmare! I had to chisel out, most of the sludge, and used my shop vac, and then power cleaner to help clean the inside of the motor. I took the heads and had them pressure washed or cleaned. I took out each individual hydraulic lifter. I put each one in marked cups, soaking them in power cleaner, and use a scotch pad, and small wire brush, to clean each on, inside and out. I then put each one back together, and soaked them in motor oil. I replaced all push rods, rocker arms and the two shafts with brand new ones. I put everything back together, and the motor was still clicking loudly! I wish I had replaced the lifters with new ones, but they were $22 a piece, and there is 12 of them, and at the time, I was on a budget, and had already spent about $300 on that particular attempt tp repair, or elimate that loud valve clicking noise. The cam may also be causing and/or contributing to that particular problem, but also, at that time, I never really considered it to be a potention cause.
Any way, if you can, I would greatly appreciate any help or advice with my current dilema.
Merry Christmas and Thanks,
Stephen Langston, South Carolina
AnswerHi Stephen,
Based upon your report, which was compelling and very complete, I think you need to try and test each of the components that are necessary to produce the spark and even the fuel pump for power during cranking which may also be missing if the autoshutdown relay is not closed due to a malfunction or a failure to get a signal to it from the engine controller due to a failure of either the crank or cam sensor. I have a copy of the '96-99 Haynes manual for the Vans which is well written on doing all those checks, and I suspect the one for the next earlier set of years (?-'95) would probably not be too different but would be worth trying to locate and if not then the '96-99 would do. Are there any auto parts stores,library or used book stores in your vicinity where you could find a Haynes manual?
You basically need to verify that the autoshutdown relay is providing 12v by means of a voltmeter or an LCD type visual testor placed between supply pin and engine ground (the supply pin of the spark pack plug is connected to the dark green/orange wire of the four pin plug), when you are cranking it for a full 5 second crank. If not then there is a problem with the crank sensor or PCM or a basic voltage supply issue, so tell me if you get no 12V or 12V for 2 seconds instead of the full 5 seconds. If there is power on that wire, then you have to test the other 3 wires on that plug with a 12V LCD-type voltage testor to see if you get light pulses on each of those other 3 wires while your are cranking, and again if not, then it is either the sensors or the PCM. When doing these three driver tests you will put one wire of the testor on the battery + post and the other on one of the three driver pins of the plug. Be very careful to not touch the tester wire to the pin for the 12V supply (dark green/orange wire) by accident as Haynes warns that this can damage the PCM.
Finally if you have the 12V from the ASD and the pulsing 12V on the three primary coil "driver" wires, then you need to measure the resistances of the primary and secondary coils of the coil pack itself. The three primary sockets on the coil should read 0.45 to 0.65 ohms between each of them and the socket for the incoming 12V wire. And then measure the resistance between the paired secondary towers (1-4,2-5,3-6) which should be 7,000 to 15,800 ohms.
These resistance value are for a temp of 70-80F so you might want to remove the coil pack and do the measurement in your warmer home location. Also be sure to label the spark plug wires/towers to be sure to get them back in order.
I do have the wiring diagrams for the '93 van from the Chrysler shop manual and I can xerox and mail you those. The only 3.8 wiring diagrams I have are from a '91 shop manual which may not accurately reflect the harnesses going to the engine you are working with but I could send you those too. The Haynes manual for 96-99 shows the wire color but not the plugs proper. The (?-'95) manual may indeed give the plug pin numbers so that would be a reason to look for that manual specifically.
So lets answer those tests and take it from there.
On the copying, I can get this done for 4 cents per page and maybe about 83 cents in postage, so let me know, I'll do the copying and you can send me back postage stamps to cover my costs.
Good luck!
Roland
