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Discussion Starter · #21 ·
It did end in 55. Didn't think I needed to post the 55. Thought you guys might think I was a total idiot.
 

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Discussion Starter · #22 ·
So, the computer is the box on the firewll......... right?

Also, the dielectric grease. Is that applied directly to the electrical contacts?
 

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The "box" on the firewall is the TCM. The PCM is near the battery on the driver's side inner fender. The incomming air to the air cleaner cools it. Pack the connector cavity with grease. Just my $0.02.

FredB
 

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Fill both halves of the connector assembly with the grease. Its purpose is to block out moisture and contaminants. The wiping action of the contacts as they mate scrapes the grease off the contact area, so the pins conduct, but everything else around it is packed with grease.
 

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Discussion Starter · #25 ·
Picked up the stuff, CRC and dielectric grease. No time to do the work yet. Wife's father passed away Friday. Been a little busy with that and high school stuff for daughter.

Bob, you suggested a diagnostic manual in a previous post. I found a diagnostic manual on ebay. It is listed as "1991 Chrysler 3.3L/3.8L EFI Diagnostic Procedures."
Would this be the correct manual for diagnosing and fixing most engine and drive train problems or does it address the EFI system only?
 

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Sorry for your loss.Actually the FSM (Factory Service Manual) has been more useful to me, as it shows how to take things apart and put them back together; wiring diagrams and physical harness layouts; and all specifications.
 

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Discussion Starter · #27 ·
fjb37 said:
The "box" on the firewall is the TCM. The PCM is near the battery on the driver's side inner fender. The incomming air to the air cleaner cools it. Pack the connector cavity with grease. Just my $0.02.

FredB
Thanks for the info fred. Now tell me what the TCM is please,
 

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TCM = Transmission Control Module, the computer for the auto transmission.
 

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Discussion Starter · #29 ·
Ok gentlemen. Cleaned all computer connections and the connection to the coil pack as well. Started right up. I let it run for about 2 minutes, cut it off and let it sit for about five minutes. Came back and cranked it again......... No start. Pulled codes 12,42, 43 and of course 55. ??????????? Any suggestions?????
 

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Code 42 1984 model injector circuit 1 open or shorted
1986+ models: ASD relay open or shorted
Code 43 Ignition coil driver circuit open or shorted

What condition were the pins and receptacles in? Was there any green corrosion? Any of the contacts have small pieces broken off?

If not the connection, then it may just be the ECM after all. But I'd give it a few more tries before condemning it. I'd also unplug and plug in the ASD relay a few times, in case there is a poor connection there. That could also give these codes.
 

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Discussion Starter · #31 ·
I had a few people tell me to change the crank position sensor. The parts guy at the local Dodge dealership among other people have suggested that.
 

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Discussion Starter · #32 ·
I couldn't see any problems with any of the contacts. Kinda small and tough to see though.


Also Bob, What is the ASD relay? Can you give me a little info on that?
 

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ASD is the automatic shut down relay. It's the relay that monitors if the engine is spinning. If it senses the engine is not spinning (using the signal from the crank sensor) it shuts down the power to the fuel pump. The relay often has other names. I'm not sure where it is located on the 1991 van as I'm pretty sure the 1991 van I owned years ago did not have the power distribution box with the relays all located together.

Code 43 can also indicate a misfire. Hopefully the old plug wires have been changed to eliminate them as a possible cause. The crank sensor can sense even minor variations in engine RPM to sense a misfire. The crank sensor should set a code 11 if it fails but often does not. Your situation isn't a common crank sensor failure. They usually fail hot, not cold when intermittent.
 

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Discussion Starter · #34 ·
Well, no I haven't changed the plug wires yet cause they look so dang good. But, I think Bob told me I should change them, just didn't rrealize it was that much of a priority when diagnsoing a no start condition and the wires are in such good looking shape. Just don't want to throw parts at it blindly cause if I do that then it would be cheaper for me to just take it to a mechanic. Also, trying to learn here. The vehicle is a 91, which makes it 22 years old. I imagine it would be cheaper to make payments on a newer vehicle than keep a mechanic on "retainer." It was my moms van so it has quite a bit of sentamental value. So, I feel the only sensible way to keep it running is to wrench on it myself, however, the down times are becoming an issue with me working on it. Seems to tqke a week or two for me to fix it.

Now, if I were to get plug wires, what brand would you recommend? I'm having trouble getting OEM parts so aftermarket seems to be my only choice on many things. What would you guys choose for a quality repalcement?
 

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I use Belden wires from NAPA, because they were OEM for Chrysler and are good quality.

Do you have an ignition rotor? If so, replace it also, and the dist cap. I had a rotor that caused a sudden no-start with only 20K miles on it. Took me 2 days to figure it out. Usually I replace them every 15K miles, because the tip chars.
 

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Discussion Starter · #36 ·
I tapped on the ASD relay with a small hammer and it started right up. Now I can't seem to get it to act up again so I can see if the ASD relay is really the cause. I also found the insulation around the wires that connect to the camshaft sensor to be cracked a tiny little bit and when I fiddled with the wire the insulation crumbled off right from the connection socket up the wire about 2 inches. Can't really replace the wires since they snake under the intake plenum all the way around and over to the connections going into the PCM. Gonna clean em up best I can and apply some liquid electrical tape in several coats to build it up. Don't know if that has anything to do with the problem or not, but if it doesn't at this time it surely will in the future. Still haven't replaced ignition wires since the only auto parts stores open today are O'Reilly's, Auto Zone, and Advance Auto. Don't always get the best results from their replacement parts.
 

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For repairing those wires: I've never used liquid electrical tape, but I recommend 3M friction tape. It's far better than electrical tape, it sticks better and better the hotter it gets, and it holds great in the cold. It's basically the same tape that the factory uses to wrap the wires together.
 

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Discussion Starter · #38 ·
Thanks for the suggestion Bob. I don't think I could've gotten tape around those individual wires since the exposure was right up against the connection plug. Would like to have replaced, but looked like a tremendous ordeal.
 

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Discussion Starter · #39 ·
Put on a new ASD relay and been trouble free ever since...... except for the milage. Down to about 11 mpg now for some reason. was getting about 15 to 16 around town. My 8500 lb 4x4 work truck does that good. OUCH
 
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