[pSun]

The trusty family convergence has developed an intermittent stalling condition. This vehilcle has recently had a SUPER TUNE-UP (air filter, spark plugs, wires, distributor cap/rotor, oil and filter, cat back system, cooling system flush and new thermostat and radiator cap). While driving the 1990 Plymouth Sundance, 2.5 liter automatic, it will at random STALL, usually around idle speed but it did it once parked (wouldn‘t start) and 2 or 3 times at very slow vehicle speeds, near idle. In the past anytime I had an Automatic transmission vehicle that stalled, it was the torque converter; if this is due to the torque converter I will be happy because then I don’t have an intermittent electrical or fuel delivery problem to trouble shoot.

I have had this car August and did replace the stock coil for fuel economy. I used an Accel Super coil and it really made the MPG go up; unfortunately it died in 2 weeks. I replaced the Accel super coil with a MSD Blaster 2, which seemed lasted 2 months (sounds kind of suspicious). While stranded at a gas station, I walked to the local parts store and acquired an Accel performance coil, which continues to work. When the car stalls, it has, after 5-10 minutes, regained it’s ability to start. This puzzles me and leaves me with too low a reliability factor to drive the auto until resolved. I pulled only code 052 (lean condition) just prior to this more frequent stalling (5-10 miles maximum without a stalling event). Prior to this it did stall 3 times, at low engine RPM (usually at or very near idle speed and at a stop, trying to pull from a stop and usually on a slight incline).
Any thoughts or insights are appreciated, as this is currently my back-up vehicle. :frusty:

 

[Doug D]

Replace the HEP (Hall Effect) - it's underneath the rotor/distributor cap. They should only cost about $20-$30 and takes 5 minutes to replace. A faulty HEP will cause stalling and a temporary no start condition. As soon as it cools down - 10-15 minutes - you can usually restart with no problems.

 

[Bob Lincoln]

If you don't get a code 11 or 54, then I'd put the stock coil back before doing anything else. I think that's what's causing your problems. Aftermarket coils do almost nothing for performance or gas mileage on a stock engine.

 

[pSun]

Doug D- I am on the Hall Effect, after verifying the codes!

Bob Lincoln- I will run the fault codes and reinstall the Stock Coil. Bob I do respect you and what you are saying about aftermarket coil performance but I can tell you with complete assurance that I did experience a pronounced and marked improvement in fuel economy when I changed the coil alone (from 14.4 mpg in the city to 16.7 mpg in the city), it isn't worth an intermediate stalling though.

 

[Bob Lincoln]

16.7 mpg is not remarkable for these cars, it is actually low. So the coil change did not get you any performance better than stock, it's still substandard. Something is wrong, and with two coil failures, I'd put the OEM style back.

 

[Doug D]

I agree with Bob. 16.7 mpg for a Sundance is horrible. At a minimum you should be getting 25 mpg or more. My Acclaims' (a heavier car) averaged 24-25 mpg in combined driving easily - upwards of 26-28 on the highway. The Sundance is lighter and should get slightly better fuel mileage. Heck, my Hemi-powered Ram (see sig) averages 17.4 mpg.

I'd at least go back to the OEM coil. A hall effect failure doesn't always set a code.

 

[Bob ONeill]

Doug D- I am on the Hall Effect, after verifying the codes!

Bob Lincoln- I will run the fault codes and reinstall the Stock Coil. Bob I do respect you and what you are saying about aftermarket coil performance but I can tell you with complete assurance that I did experience a pronounced and marked improvement in fuel economy when I changed the coil alone (from 14.4 mpg in the city to 16.7 mpg in the city), it isn't worth an intermediate stalling though.

Question... did the coil cause the intermitant stalling? Is it possible that your original coil was week and that replacing it with a stock unit would have provided the same improvment?

 

[Dave Z]

... anyone look at the MAP sensor?

 

[pSun]

Bob Lincoln-/ Doug D- While I agree that the engine is not performing at it's peak, after completing a FULL tune up, the city MPG did climb from 14.4 to 20.6, I was only addressing the change from the coil alone. I know that this, when it was new achieve MPG numbers close to 30 on the highway and 21-22 in the city, not that there isn't more potential in it. I am glad you are willing to let me know it still isn't at par with what it should be doing.

- when the stock coil was in, the engine stumbled and spit quit a bit and was only capable of 14.4 in town. It started slow and with alot of effort and key, these conditioned screamed weak coil to me, so I just tried it. I felt a large seat of the pants difference, my 15 year old daughter even asked what I had done to make the gas pedal work better/easier. I don't want to separate the pepper from the salt and can see from the supportive words for the stocker coils that when in good condition are dependable components worth keeping stock. For those oppinions and facts, I thank you guys.

Bob ONeill- The original Stock coil was weak, that is why I chose the Accell Super Coil. I am not accustomed to STOCK coils outperforming Accel or MSD but I can see now that these Dodge coils must be worth using.

DaveAdmin- I have not looked at the MAP sensor yet, I will look into it tonight, pull codes and see what is up with it.

I did manage to aquire a new hall effect sensor today, so tomorrow after the dust settles, I will remove/replace the old one. I have the stock coil and enthusiastic about using it to trouble shoot this condition, Thanks for all the assistance, I am getting there, slowly but surely.

 

[Bob Lincoln]

What diagnostic led you to believe that the original coil was weak? Did you do resistance measurements on the primary and secondary? Consider that perhaps it was corrosion on the coil wire or the primary wire contacts, and that simply unplugging and plugging the wires cleaned up the corrosion, and that may have been the cause of a weak spark, not the coil itself.

 

[pSun]

Bob Lincoln- thanks for your continued interest and assistance. I did perform resistances check on the coil with my Fluke; it read just out of spec, while still working (marginally). I did clean the contacts prior taking the reading. For the record, I am O.K. with using a stock replacement (especially when the aftermarket is subpar), I wish I would have asked here before I bought the Accel... and I am not a "stock" basher, I simply, have had good results using the Accel products on my Fords.
-yes, it is also possible that the wires are corroded. i will have to read out the wires, good suggestion. :cheers:

 

[Bob ONeill]

If the Accel is not causing the intermitant stalling use it. IIRC it produces a hotter spark and that can't be all that bad.

I can see how a hotter spark or a different spark curve might improve things a bit. While the stock coil is fine for stock engines now that you have invested in the Accel there's no sense in letting it go to waste. :thumbsup:

 

[pSun]

Thank you all for your concern, opinions and for caring. I have to let you know what the problem was and how I missed it, hopefully without making excuses.
Since I just recently performed a "super" tune-up, I had ruled out all of those components as contributing to the fault, poor assumption. After the tune-up, I had a small leak from the hard line on the bottom of the water box. While it did leak, initially, it let out a fine steam which was spraying on the distributor, cap and rotor. I didn't think about how this may effect the electrical components within. When I removed the cap and rotor to check the Hall Effect sensor (AKA: ignition module), I noticed that the hall effect sensor was very clean and all the metal parts looked perfect. I also noticed that the wire coupling was moist. Then I took a good look at the rotor and distributor cap; they were very carbon deposits covered and or showed heavy oxidation. I realized at this point that my fault was most probably the heavy carbon deposits and oxidation and that it was due in part from the water box leak.

After cleaning everything up, I covered the metal parts with dielectric grease and cranked her over. She started VERY QUICK, with minimal effort, the idle was solid and authoritative! I took it for a test drive and have determined that this was the cause of my intermittent stalling. I will return the ignition module as it does not need replacing yet.
One question I have to ask is how often should I clean the distributor cap and rotor; this was after a mere 3,500 miles, plus or minus 500. What I have decided to do is check them once a month and do a zippy copper wire brush clean-up, then dielectric grease...job.

While I am not sorry for asking for help, I am sorry that I am this honest (admitting to the www that this is one of the first things I should have checked). On a more positive note, I let my daughter son each clean part of the distributor cap to see what was actually making the car not work. They weren't very interested but I am hoping for a pseudo osmosis thing with them and someday when stranded on the side of a desolate road at night, in the cold and rain, equip with only a small insurance quote complimentary tool kit, they remember what simple little problems can keep these cars from running.

 

[B10alia]

These cars have a reputation for burning out rotors in particular rather quick, sometimes within 10k. I like to check my rotor when I do my semi-sort-of-regular checks (plugs, oil, coolant, PS, brake fluid, air filter) which I do roughly every 1k. I don't know about dielectric grease in there, it's a very high-voltage, high-heat environment. Plug wires are too, but if you take the rotor off and spin it inside the cap like it would in the motor, you can see the size of that gap- it arcs constantly, by design, and I'm not sure how dielectric will hold up, could possibly pose a hazard. Besides, it's nonconductive, so you're making the coil work harder to arc that gap. Around the base of the cap might be a good idea, but not on the rotor or wires. The wire terminal ends can be flipped over when they get too pitted. Wire brushing is OK, I do it as part of my tuneups, but it will not get you any more life out of the rotor; the engine will still burn it up.

 

[Bob Lincoln]

I do not inspect the rotor between replacements, I just replace it every 15K miles. I would advise against sanding or brushing or scraping the rotor and the distributor button. The rotor is nickel plated, and when you sand or scrape it, you cut through the plating to the base metal, which will cause rapid oxidation and pitting, and make it fail faster. Just change it if it needs it. Glad you found the trouble.

As for dielectric grease, a tiny bit inside each wire boot at the distributor cap can't hurt, but nothing inside the distributor.

 

[mopar88]

check the egr valve maybe?

 

[dana44]

Agree. Dielectric grease is for connections, not moving parts inside a distributor, boots are a different story, they are fixed. Oxidation or rust (aluminum oxide or copper oxide, depending), tends to form faster with stronger coils, a check every oil change would be often enough, the metal crowns inside the cap can be cleaned/scraped inside the cap, change it every other oil change or once a year if it is getting this corroded, but do leave the rotor alone as stated above. Be sure to wipe the metal rust/powder out of the cap the best you can, it is capable of having a spark track along from plug to plug, thus misfiring by carbon tracking. Glad you found the problem, it's almost always something not expected.

 

[Bob Lincoln]

dana, these don't have metal contacts inside the cap. They have a spring-loaded carbon center contact, and they have spark plug wires with locking prongs that extend thru slits in the cap to make the individual contacts.

These prongs get charred with use, and at 15k mile intervals I remove the wires, rotate the prongs 180 degrees and use the fresh backside of the prongs, along with a new rotor. At 30K intervals I change the wire set, dist cap and rotor.

 

[dana44]

I gotta get to the junkyards and look at more engines. One of those odd distributor cap designs I haven't seen before. I know the center piece is what it has been for almost a century, but you are saying the actual tips through the cap to the individual plug wires is not the usual cut metal pin?

 

[B10alia]

Yeah, it's sort of like a spade terminal that has barbs on it so it goes in the cap and stays in.