[Dave Sheridan]

Hi all-
I have a '73 Scamp 225 slant 6. Last summer I changed the spark plugs (twice because the first time I didn't have the proper gap on my old gauge tool). The first time I started it up it idled horribly and after awhile it started to even out but just attempting to drive around the block was problematic (stalling) so I redid everything a few weeks later (and got a new tool!). I also replaced the fuel filter. Now it idled great and ran fine....until...after driving all day I was heading home and coming up to a light. I could feel the engine cut and fortunately was able to coast into a parking lot. Up until then, I'd driven around for a good 2-3 hours all over the place- probably about 100 miles. It was a warm sunny day (not that I've had issues with cold/damp stalling in the past, but I know sometimes older cars can be picky in bad weather).

When I tried to restart the car, it would fire up but wouldn't stay running. As soon as I took my foot of the gas it died. If I kept my foot on the gas it'd ran but I was leary about trying to drive with both feet. When I came back around midnight, it started right up like nothing had happened and drove fine. This happened to me about 3 times in the course of a week but the other 2 times I barely got a block away from home before I could feel the engine cut and die. But the same deal- it'd die and I wouldn't be able to re-start it (it'd die if I took my foot of the gas) for hours.

The dist wires and carb appear to be ok...although admittedly my mechanical expertise is about a 2 on a scale of 1-10. Any other thoughts/advice as to what might be causing it to stall hot like that? :frusty:

 

[dana44]

Welcome to the forum first off.

Even though the spark plugs and wires themselves have been changed, there is a good chance the distributor cap itself is in bad shape. The tips corrode and the rust(oxide) can cause problems like this. Change the distributor cap and rotor first. The next thing sounds a quite a bit like the hall effect in the distributor starting to go bad. They tend to show they are wearing out not when cold, but when warm. If it takes 20-30 minutes before she will start again, time to replace it. The electroinic ignition itself has a gap of .008 clearance and the gap has to be set with a non-magnetic feeler gauge, about the thickness of a business card folded in half (it's non-metallic). Without knowing the car itself, these two/three things are normal wear items, the hall effect just lasts longer, distributor and cap at least every couple years.

 

[CudaPete]

possibly a fuel/fuel supply problem. The filter in the tank may be clogged or the gas may be "boiling" in the carb. Carbs do not like modern gas formlations that are designed for fuel injection systems. There is a fuel line bracket on the water pump on the /6. It can transfer heat into the fuel. You can insulate it by making a isolating bushing out of rubber hose. I'm familiar with the Halls effect sensor in the 2.2 but not in a /6.

 

[valiant67]

I would look at the pickup coil as Dana suggested. It can fail when subject to heatsoak and then be OK once it cools.

But a quick idea the next time it fails is to check for spark. If the spark stays strong then it's fuel related.

 

[CudaPete]

Doesn't the /6 distributer use a variable reluctor rather than Halls effect?

 

[dana44]

The reluctor is the part on the distributor shaft the hall effect almost touches to spark the rotor in the proper order and number of degrees to the six sparkplugs. Don't feel bad, I had to double-check the proper name. Rockauto calls it a hall effect, too, but believe it or not, you can get new reluctors, too!

 

[Dave Sheridan]

Thanks guys- I actually changed the electronic ignition module a couple of years ago but didn't realize there was a gap setting to it. The gas tank was clean,but the distributor is probably a good 10+ years old (it was a daily driver up until about 2004), so I'll check into that and cross my fingers.

Hopefully the dist cap will fix the problem...I'll take a look at insulating that fuel line, too.
Thanks!!

 

[Bob Lincoln]

Doesn't the /6 distributer use a variable reluctor rather than Halls effect?

The reluctor setup IS a Hall effect switch. The reluctor wheel is magnetic, and there is a pickup coil at the magnet on the ignition module in the dist.

 

[CudaPete]

I think they are different in that the variable reluctor induces a voltaged based upon the changing flux in the magnetic field while the Hall Effects sensor varies a supplied voltage in repsone to the changing flux in a magnetic field. The Halls Effect Sensor can show a ture zero RPM this way and is more precise.

 

[Bob Lincoln]

Nope, exact same technology. The reluctor is the same as the shutter in the 2.2L distributor.

 

[CudaPete]

They are not the same. A variable reluctor acts as an electrical generator and induces an AC signal in the form of an analog sine wave that goes to the spark box to tell the coil when to fire. The Hall Effect sensor acts as an electrical switch that takes a supply input voltage and produces an output voltage in the form of a square wave that is a digital input to the logic module. This data is used to tell the coil when to fire.

 

[chuzz]

You say you changed the ignition control module. Is this what you changed? http://www.autozone.com/autozone/parts/1973-Dodge-Dart/Ignition-Control-Module/_/N-ip5y9Z9n80t?filterByKeyWord=control+module&fromString=search If not, this is a possibility. Your local Autozone, or Advance Auto can test this.

 

[Dave Sheridan]

Yes, that was the part I changed. The pickup coil was changed but it still hesitates. :-/ The gas doesn't seem to be boiling, either.

Is there something that would short out the module or distributor? Alternator, lose belt? Would the timing have to be adjusted again after the dist is replaced?

 

[dana44]

Timing adjusted after distributor replaced, but that wouldn't make the engine just up and stop just because she is warmed up and driven a while. Electronics don't like heat, and pickup modules and electronic control boxes do fail at times, cheap parts and all that tend to fail more often than factory spec pieces.

 

[Bob Lincoln]

Did you gap the reluctor in the distributor as suggested? That can cause this problem. .008 inches with a brass feeler gauge.

 

[Dave Sheridan]

I didn't check the gap...thanks for reminding me!

 

[Bob Lincoln]

It caused very rough running, poor (hard) starting and stalling for a member who was at Carlisle last year. Bob O'Neill and I fixed it on the spot by setting the gap.