Dan's Engine Problem Thread

[bordin34]

As some of you may know my engine has not been running right for a long time. Last week I replaced the valve guide seals and I took it for a test drive yesterday. The car ran much better than before, but under WOT and only WOT the tach would jump around like crazy like fast sweeps from 3000-9000rpm. Most of this about 30 minute drive it ran fine. When I hit a stop light in the beginning the engine was smooth and constant. Then after about 20 minutes, about 10 minutes of 50-65mph on the highway, at 3000rpm, I was stopped at a light and it was surging a little bit. The next light about 2 miles away the surging got worse. Then as I was rounding a bend on a green light just as I was at the apex the engine went dead, no warning sputter or anything just dead, which was kinda scary with the power steering just locking up. We found out that the battery was dead and we were able to jump it and drive the car home. Would a dead/non-charging battery do this? I had no accessories on. I would think the alternator should be able to keep up even with a dead battery. Could this be vapor-lock? Also I believe my transmission, 727, was not shifting out of second on the highway, I have 2.45 gears and 3000rpm shows 2nd gear on that cool speed calculating website.
Thanks,
Dan

[Supercuda]

Time for you to answer a few questions, so that yours might get a good response. Was the ammeter showing a charge? What electronics are involved with your ignition system? Have any ignition or charging/starting system parts been recently replaced? This sounds like a simple problem, but it is often mystifying when a strange result comes from ordinary causes. If there was a problem with the charging system or the battery that caused voltage spikes or low voltage in the ignition system, it could create the symptoms you are describing. Is the tachometer an aftermarket unit, or factory? If aftermarket, how was it installed? We'll get this sorted out, I'm sure.

[bordin34]

The ammeter was in the middle whenever I looked at it. It is a stock electronic ignition system. No parts of my charging system have been recently replaced. The tachometer is a probably 20+ year old aftermarket sunpro knock-off. Installed the tach my putting one wire on the coil and the other on a ground, I didn't hook up the light.

[Supercuda]

Check your charging system, as the needle should move towards the "C" from center, every time the car runs. The stock ignition system runs poorly on voltage below 12V, and stops working at about 10.5V. The specs often say "at least 9.6V" for running, but the stockers I've seen in my life, always stop working at about 10.5V. So, check the charging system, then let's worry about the rest of it. The tach was responding to a "garbage in-garbage out" condition, as the control box for the ignition wigged out on the low voltage. Keep us posted.

[GreenFish]

Honestly the first thing I would do is convert to an MSD ignition system. Not sure if you are looking to spring that kind of cash but they sure are an upgrade to stock stuff.

[Moparal]

Please keep us informed on what you find wrong.  2nd gear riding at around 3k might have let the belts slip maybe, not sure. Electronic ignitions need a certain amount of voltage to function, just like supercuda says.   Make sure you check all connections at the realy, fuesable link, firewall, check the plug in connectors for the alt wires, voltage reg, ballast resistor.

Use a volt meter when the car is off, have someone crank the car while watching the volt meter up under the hood. It should go from around 12.6v o around 13.8 or more after it cranks

[bordin34]

Thanks, I will check my connections and fuses. The trans never shifts into third, or at least I don't think it does, and the kickdown it adjusted properly.

[bordin34]

Also, my positive battery cable was not on that tightly. It was loose enough that I could twist and pull to easily take it off. Would this cause a no charge problem?

[bordin34]

I just went into my garage and gave the wiring a quick check,I found that the green wire that goes into the top of the alternator was cracked and not connected, right now it is temporarily connected, but I need a new blade type terminal.

[Kapteenikosmos]

Isn't that the wire that enables the alternator to charge (the wake up wire or whatever it is called)? That would be a pretty obvious reason for the poor running engine and a dead battery.

[bordin34]

It could be there are two green wires going into my alternator. On on the side/bottom the other on topish.
So what would cause my trans to not shift into 3rd gear?

[Supercuda]

It sounds like you have the source of your charging problem identified. The field wires are necessary for proper charging. A MOPAR alternator is set up in one of two ways: one wire to a single field terminal, and the alternator needs to have a decent ground in order to charge; two field terminals, and two field wires to the alternator. One is hot, the other is a ground wire, switched by the voltage regulator. This requires a good ground at the regulator for proper charging. As for your trans issue, the questions you need to answer are these: 1) Is the trans the factory unit or a rebuild? 2) If a rebuild, were any mods performed? 3) At what speed does it shift into second? 4) Is the shift firm or sloppy, and if firm, does it seem a little too "aggressive"? Most problems of this nature come down to either the valve body (sticky shift valve), or the governor (wrong one, or malfunctioning).

[bordin34]

As far as I know the trans is a factory non-rebuilt unit. I am not sure what speed it shifts into second but it seems firm but not too firm. The only problem I have had with the trans in it leaks a little bit and it sometimes make a squeaking sound in reverse that goes away after a couple seconds.

[Supercuda]

You might be hearing the dreaded "3rd-reverse drum death-rattle", which would explain the "no third" complaint. When I killed my last front drum, the engine required an extra 1000 rpm to get anywhere in 3rd gear. The metal and paper in the trans pan when I dropped it, was the confirming sign. Have you serviced the transmission? It's still possible that there is a shift valve hanging up, and you can hear it in reverse. Let's hope for the best.