Engine dies? Ideas theories

[Doubleclutch]

New car to me --73 Road Runner 440 with 52k original miles. I drove her test run about 20 minutes and then bought her home 60 Miles mostly on the interstate. No problem.

Put her in for complete fluid change, new high torque starter and rear brake rebuild.

Incident 1 backed out of garage dead cold, turned left and died. restarted and was fine.

Incident 2 fully warmed up stopped at a stop sign, moved away turning right and died. restarted and was fine.

Car has a recent electronic module, mounts on the firewall? I'm not enought of a mechanic to say what it is. (to the right of center on the firewall)

Car has a failed safety start switch. We had it on the list at the mechanics but couldn't get one--starts fine in nuetral but not park.--decided next trip in.

Doesn't act like fuel. No sputter or caugh just lights out dead. No rough idle.


Starter work envolved? never died until new starter but seems fine and restarts even and smooth?


Ideas??

 

[Al K]

Wiring at the starter/loose connection at starter? Any wires from the ignition components with a cut in the insulation? My '64 does weird **** like that at times.

Just suggestions,mind you;I'm not an electrician nor do I portray one on TV.

 

[lewtot184]

it probably is a fuel issue if the problem occurs going around corners; maybe float levels. not starting in park may be a linkage adjustment rather than the switch.

 

[MarPar]

more timing!!

 

[Pops1967GTX]

It could be a ton of things. Process of elimination.Check grounds at starter, Check ECU for a bad ground.( Remove & sand firer-wall).Check Burkhead connection for bad ground.Check pickup in dizzy.(Adjusted the pick-up coil / reluctor gap to the recommended 0.008"). Could be coil problem. However if you want to rule out an ignition switch issue, what you can do is run a 12v wire directly from your battery to the 12v input. . This would bypass the ignition switch.Possible bad gas, check fuel filter,stuck float,acceleration pump.Vapor Lock?

 

[terzmo]

every turn ?? I'd start with what was worked last if this is a new issue with the car...check the wires on the starter to see if the are touching anything

 

[Al K]

more timing!!

...More Cowbell!


Mario;ya left that door open. Who did you think would step through?

 

[Doubleclutch]

Thanks for the list.

Giving it more thought it happened both times right at initiation of acceleration--not idle. And the car has a very slight hesitation at initiation. Its very slight when warm and more when cold. I was going to increase the push on the accelerator pump even before the dieing began.

This car has only been driven 2000 miles in the last 10 years so fuel problems are definitely in the picture. However the carb was rebuilt a couple of years ago by an "oldtimer" in the local Chysler dealership. If evidence of gunked up fuel was found I would have hoped a dealership would have cleaned the tank.


Will check the ground to the ECU and accelerator pump tomorrow.

 

[MarPar]

...More Cowbell!

i gotta fever...

 

[coloradodave]

Less cowbell...

 

[Al K]

Doubleclutch;does it cut out quickly(like "flipping a switch") or"slowly" die? Seems an electrical issue would be sudden;fuel might give a "slight" indication of an impending problem. Good luck!

 

[tpodwdog]

ballast resistor is failing. replace it!

 

[Meep-Meep]

Well, for a sudden lights out kind of failure I'd have to agree it's electrical. Where were you last? The starter. What is near the starter, or above it? The bulkhead connector and the fuseable link from the starter relay. Did you lean on or somehow pull on wires trying to fish out the battery cable and now something may not be properly connected? I'm not familiar with the electrical component layout of the 73 but I don't think it's too far off from my 66/69 cars.

 

[Bruzilla]

I would agree that if the engine is cutting out abruptly, the problem is electrical and not fuel. Since it only happens in turns, I'm guessing you have a bad/loose connection somewhere on the ignition circuit. When you turn, centrifugal force acts on everything in the car and causes directional forces that aren't present when you drive straight, so a connection that's good when you're not turning might be getting pulled open in a turn.

I had a similar problem years ago on a 73 Road Runner. The POS wire to the coil looked fine, but the connector had failed and the wire was in contact with it through tension only. When I made a hard right turn, centrifugal force pulled the wire away from the connector and poof! circuit broken and car dead.

 

[Doubleclutch]

I'm leaning more toward electric ---the suddenness, no spitting, no caughing, and clean restart.

The first incident was in the driveway just beginning a left turn just starting to roll. There was no centrifical force from the turn. The second was a roll through stop sign with a hard right turn with some centrifical. The engine torque would have shifted the engine slightly in both and thats the strongest hint.


I'll start eliminating this evening after work.

 

[Doubleclutch]

I might have it. The 4 by 4 aluminum box on the firewall , which I believe to be the ECU, is leaking oil--or somthing? down the firewall. Looks like at least a teaspoon and maybe more where it disappears behind a fender pan.

I checked all the wiring battery to starter from above. I'm not going to mess with the carb until the ECU is fixed.

 

[Budnicks]

I might have it. The 4 by 4 aluminum box on the firewall , which I believe to be the ECU, is leaking oil--or somthing? down the firewall. Looks like at least a teaspoon and maybe more where it disappears behind a fender pan.

I checked all the wiring battery to starter from above. I'm not going to mess with the carb until the ECU is fixed.

I would start at the starter 1st, if that's what was changed last & it ran good before that part was changed, the bulkhead connections are notorious for issues too, coil could be bad or going bad too, ballast resister, maybe the fusible link is almost gone or gone & loosing contact in turns etc., or maybe even like MarPar said "a little more timing advance" will help the off idle stumble a little bit too, but "probably" not a related issue to the dying suddenly thou... there is no oil in the ECU to leak, "that I'm aware of anyway", some do have an epoxy backing sometimes, I doubt & don't & wouldn't think it's the ECU leaking thou... I wonder if it's a bad ground at the ECU, a loose wire or bad connections & or ground, it will cause starting &/or running issues with out good contact/ground, I always make sure I have a really good bare clean surface & use dielectric grease on all electrical connections, I always run a 8ga. or 10ga. ground wire from the back of the cylinder head or intake to the ECU mounting bolt, or just run the original braided "engine ground strap", if it's long enough to reach where your ECU is mounted, to one of the mounting bolts, for a really good ground, for the ignition system... you can go to www.MYMopar.com , they have electrical schematics for allot of 60-70's Mopars, to be able to identify or trace any trouble wire you find... good luck electrical gremlins are a pain in the ***... there is also a good site www.MadElectrical.com , has a bunch of good info on tech issues & tech fixes, especially on the bulkhead connectors & wiring, along with electronic related parts & wire...

 

[Doubleclutch]

Hi on the ECU question. There's a thread in the A bodies forum that cites a ECU meltdown.

"I know it isn't unusual for gummy junk in the electronic ignition control module on the early 70's to melt and make a mess. My question is, how do you clean it up? I am cleaning up to paint and can't find anything that will take this stuff off. I scraped all that would come off with a razor knife, and have tried mineral spirits and super clean on what is left, with no luck. This is on a 73 Duster".

I know I have something running out. The car came with one in a box in the trunk. I assume its a failed unit-- will look it over tomorrow

 

[Meep-Meep]

That goo in the ECU is an epoxy and won't hurt anything if it comes out. Of course it's not supposed to come out but if it does that would indicate something is wrong with the epoxy and not the electronics.

 

[Doubleclutch]

Think we got it. The ballast failed and probably cooked the ECU. Yes they do drip when operating at too high voltage. The hesitation is probably the improper voltage from the ECU going from idle RPM voltage to RPM voltage at 14 plus. The perfect restart is the full 12 volt circuit going to the coil as I follow it.

I'll run it in as soon as dry weather gets here.