[ImperialCrown]

Any stored fault codes?
http://www.allpar.com/fix/codes.html
You may want to invest in a factory service manual or better yet, the 1991 Powertrain Diagnostic Procedures manual if you are going to fix this yourself.
http://www.thefind.com/cars/info-dodge-powertrain-diagnostic-procedures-manual

 

[valiant67]

Once it starts, does it run OK or stumble a bit until warm? I had a coolant temp sensor (the one for the computer, not the one for the gauge) fail and cause hard cold starts. Obviously whatever code has lit the check engine light is where to start though.

 

[fandini]

Once it starts it runs fine. No stumbling at all. I have a factory service manual, but no powertrain diagnosis manual. I'll do a search for one for sale if you can tell me exactly how the powertrain diagnosese manual is labeled. Tried to get codes at O'reilly's but the guy couldn't find a compatable plug for a 91 Plymouth

 

[Bob Lincoln]

No code scanner is necessary. Use the procedure above that Imperial Crown posted in the first link, all you need is your key, and you can get the codes yourself. Please post here after reading them.

 

[A.j. Schreiber]

hmmmm bad intake gasket causing a lean condition?

 

[fandini]

Been at work all day then had a high school track banquet to attend with my daughter as soon as I left the job. Haven't had a chance to do anything with it today. Will jump on it tomorrow and post the codes as soon as I get them. A.J., I hope it's not a bad intake gasket cause I just put new valve cover gaskets and upper intake plenum gaskets on about a month ago and she was running like a champ with no leaks. Will post tomorrow. Thanks!!!

 

[valiant67]

I doubt it's the intake gasket. I can't see that causing a star issue but then no other issues one it's running. The leak would tend to make it lean at all times and especially lean at idle.

 

[ImperialCrown]

Possibly a long crank time from a fuel pump having to build up fuel line pressure due to an overnight fuel leakdown back into the tank?
There is a check valve that is part of the pump to hold fuel in the lines after shutoff that can fail.
A fuel pressure gauge will show a rapid fuel rail pressure drop after shutting off the vehicle. Upon restarting the next day, the gauge may take some time to build pressure.
If it starts up after pressure builds, the pump and possibly the tank insides will have to be investigated?
There may be a schraeder valve screw port on the front fuel rail for quick and easy fuel pressure testing.
Poor fuel economy may be an unrelated problem and due to a rich condition that the 'ck eng' light may explain.

 

[chuzz]

When's the last time you put plug wires on it? You don't mention the mileage nor the last time you did a tune up. I do know that if you have the OEM wires and a lot of miles on them, that cold weather can keep it from starting. The cold seems to really mess up the resistance on old plug wires.

 

[Bob Lincoln]

Resistance decreases with cold. Cold causes condensation, which tends to short out marginal wires.

I agree, if the wires, plugs, rotor and cap have more than 50K on them, replace them.

 

[fandini]

OK, here we go. Here are the codes listed in order of displayed to me.
12
42
43
43
43
51
15
New wrinkle, drove today. was 60 degrees out here in North Carolina and it started right up. Drove for about 15 minutes and stopped at the gas station to get gas. Was plenty warm at that time. pumped a few bucks of fuel. took about 10 minutes. Wouldn't start after that. Cranked it about 20 or more times. Opened the hood and looked for something loose. Went back, cranked it a few more times and still nothing. Not a spark, or stumble or any indication of trying to start. went and looked under the hood again this time with a flashlight. Still could find nothing out of the ordinary. Went back cranked it again and it started after about the third crank like absolutely nothing was wrong. No stumble, miss or anything at all. Did however have a noticeable ticking which went away after about a minute.

To respond to some of your posts, spark plug wires have never been replace but they look good. Did just replace plugs a month ago which looked quite rough.Only 66,000 miles on this little mini box. Did a little maint on it in October which included new vavle cover gaskets, new pcv valve, new plugs, trans service, oil change and a couple hoses replaced.

One small note, I've noticed that I can smell gas when it's been filled up, but that has been like that for at least a year. New fuel pump put in in July which was done by a local shop. I did find a hose pinched between the brake booster and the firewall which comes from the rear of the vehicle. Not sure if the comes from the AWD overrunning clutch or a vapor line coming from the fuel tank area. I do know that it is plumbed straight to the back of the intake plenum which leads me to believe it goes to the overunning clutch since it seems to be a vacuum dedicated hose.

Don't think I can add anything beyond that at this point. I'm sure this is now sensory overload.

Any and all help is appreciated!

Thanks!

 

[Bob Lincoln]

With all those codes and symptoms, I'm going to say I'm 99% sure that you have bad connections at the ECM. The contacts in the plug and on the computer side are probably dirty, maybe corroded, and the contacts may have spread apart a little. Undo the negative battery cable, then the plug to the computer, and clean all the pins and receptacles on both sides of the connection. Repack with dielectric grease (auto parts stores and Radio Shack have this). Reconnect battery. If you are diligent in this, I can almost guarantee the problem will go away.

And change those 22-yr old wires. WOW. You can't tell from looking. They will be marginal. I'd change the cap and rotor, too.

There are no vacuum lines to any Chrysler transmission. They are all hydraulically and/or electrically controlled. If that line goes to a small canister on the brake booster, it is a vacuum check valve for the heater control function.

 

[fandini]

Thanks Bob. I'll work on that cleaning. Any suggestions on what I should use to clean these contacts, solvents, brushes, tools? Don't want to screw up any wires or connections. Parts are getting very difficult to get!

Also, vehicle is all wheel drive and best that I can tell there are what appears to be hoses running to the drivetrain module at the rear end of the vehicle. I think that is the overunning clutch but I could have that term wrong. Look like vacuum lines to me but I'm a weekend guy and not a pro.

No rotor or cap on this 3.3L V6 moster! She's sportin one big honkin coil pack!

This was my moms van and was kept in a carport. Condition is pretty good for it's age. Not driven much, only about once a week by my dad. Only 66,000 miles on it and 6000 was put on it in the last year alone by my wife and daughter. Was given to us about a year ago and have been kinda takin care of some small litttle maint. items as time passes. Getting the most important stuff first and then kinda replacing, repairing other stuff as I go. Daughter is in high school and "On the Go" so I don't get much opportunity to work on it. Surprisinly the plug wires look phenominal! Clean, no cracks or flaking on any of the rubber components or insulationn and very plyable and flexable. I am aware of the degredation that takes place on these components though and I have been considering replacing them eventually but you would not believe how well this thing starts and runs up till this week. It NEVER misses, stumbles or acts like anything other than a brand new engine. It really surprises me. It's 22 years old however and It needs quite a few things that I have been trying to address gradually. Most of those are leaking drivetrain components and some engine gaskets. Still got a few of those to go. Big job for a weekend driveway guy but I've actually been enjoying it.That being said, ignition wires haven't been real high on the list. Maybe I should move em up a little.

Thanks.

 

[Bob Lincoln]

Radio Shack should have contact cleaner, or any store that has any electrical section. In a pinch you can use carb cleaner spray. If you can find anything like a dental pick or some such metal tool, that would be handy for digging out old grease and dirt from the female contacts.

 

[valiant67]

Given all those code 43s and that it is a misfire code, your wires are likely well beyond shot.
The only other real explainations would be misrouted wires or a bad crank sensor. My money is on the wires.

 

[Bob Lincoln]

There's a code 51 and 15 there. While 51 might be from the wires, 15 can't be. So new wires would help, but not solve the problem.

 

[Ray Green]

Any suggestions on what I should use to clean these contacts, solvents, brushes, tools?

NAPA and probably other places sell a CRC product called QD Electronic Cleaner (which simply put stands for "quick drying"). I've used it on everything from cellphones to circuit boards in half-million dollar motor homes.

 

[fandini]

You guys might be right on the wires but, considering how well and smooth it runs when it starts and is running I don't see how that could be. It never misses, or stumbles. It runs smooth as silk. Gotta be some testing that can be done with a multi meter that might show resistance values out of an acceptable range ir an electrical component was bad.

 

[ImperialCrown]

The fault code sequence should end in 55 not 15, shouldn't it? I would try reading them again paying attention to the pauses.