Loss of Power on the way to work. Any ideas?

[kkinzli]

Morning Pelicans!

For starters I have a 69T running Zeniths and have installed a Petronix.

I was driving into work this morning doing about 90mph when all of a sudden I felt a loss in power. When I step on the gas the car does not respond nearly as smoothly and quickly as previously. In conjunction with this the Tach started producing funny readings including zero at idle and only 3000 rpm when the loss in power happened (should have been around 4000). I was able to make it into work okay and think I can get her home later today but was wondering if this has happened to anyone else. It feels like I am not running on all cyclinder, or that the timing is off suddenly. Could this be something related to the distributor? Could it possibly be plug wires or plugs? I am guessing that it could be tach related as I am getting such a funny reading. I am also thinking that it could maybe be related to one of the carbs not getting enough fuel due to either a plug in the carb itself or the filter/fuel line?

Any advice would be greatly appreciated

Cheers

[twistoffat]

This thread might help

Lifespan of petronix?

[kkinzli]

Thanks for the link. The petronix I installed has only been on there since Thanksgiving (about 3 months). I do carry a spare set of points as advised by the suggested thread.

[bkreigsr]

Originally Posted by kkinzli

I do carry a spare set of points....

for just this sort of occasion - put them in. Bill K

[kkinzli]

Do you think it is possible that the petronix could have failed so quickly? It has only been 3 months!! If that is all it is an easy fix. Hope it is not something more serious

[5String43]

On a '69? Yes, a Pertronix can fail quickly - or rather cause a coil to fail. I may have this wrong, but I seem to remember that the Pertronix hates those plug-in connections that were used in the wiring looms of the 1969 cars. If I correctly recall this, resistance in those connections will cause problems. That may not be your problem. But it happened to me. I went back to points and condenser on that car.

[Grady Clay]

kkinzli,

The simultaneous tach and poor running always makes the ‘points’ suspect.
In your system, what provides the signal for the tach?
If that is failing, can it cause poor running also?
Can you test the Petronix?

Put your points back in and see how it performs.


Here are some other simple tests and inquiries:

Use your ‘Unisyn’ device (that you use to balance your carburetors) to compare high-idle air-flow between left carb and right carb.
With your “3-cylinder” description, you need to confirm both sides of the engine are running.
Jumped cam timing is always an important issue to preclude.

With the engine OFF, confirm you can get full throttle pushing the accelerator pedal and comparing to the linkage at the carbs.
A broken throttle cushion can feel like ‘three cylinders’.

Neither of these can cause the tach to act improperly but there are coincidences.

Best,
Grady

[kkinzli]

Thanks Grady!

I will look into that. I was planning on looking at the balance between carbs as soon as I got home. I am not exactly sure what is providing the signal for the tach. That is not something I have ever had to investigate. I am guessing that it is still a stock set up since there is no CD box on the car. I replaced all of the bushings on the throttle linkage 1.5 years ago. I will keep you posted as I diagnos this issue.

Where in Arapahoe County are you located? I lived on Bellview near Cherry Creek State Park for almost 20 years before moving to Florida last year for a job.

Cheers,
Kristoph

[kkinzli]

Going to try and driver her home now. Wish me luck!!

[Joe Bob]

I'm thinking fuel filter....

[Zeke]

Keep in mind that Pertronix cannot be left powered on w/o the engine running for more than say half a minute at any given time. Sounds like that's not the issue here, but just sayin'.

[Joe Bob]

Also....I've never been a fan of the Pertronix. When in the 914 world, they were much maligned. Failing out of the box, not using different colored wires for ground and 12v power.

I'm not a believer of an electronic device that "starts" to fail. Either they work or they don't. Partial fails are grounding issues and that unit would blow smoke if that happened.....it's not like whacking a B&W TV when Lucy fades out when she's whining at Ricky.

The 356 crowd at the "Registry" loves them.....but, consider the source.

[kkinzli]

Thanks for the help guys! I was indeed able to make it home last night. Toward the end she was shaking pretty badly but I was able to avoid changing into the old cloths I keep in the car and switching back to points on the side of the road. Based on everybody's advice I kept the old set in the glove box. As to be expected Grady was right The Petronix was malfunctioning. I checked the coil first (by switching to an extra I keep around), then the carbs (using the unisyn) and then the throttle linkage. All these were fine. Then decided to pull the petronix out and put the points back in. While doing this one of the nuts from the petronix fell down into the distributor so I had to pull the top plate off and use a magnet to fish it out. This also meant I had to reset the timing once I had the points back in. this turned out to be one of the easier issues to date. Thanks to all of the bigs guns at Pelican (Grady, Joe Bob, Milt) for helping me out! I will post a story about my car one of these days with a formal introduction

Cheers,
Kristoph

[Joe Bob]

Do you know why the unit started to fail? Loose wire, cut wire, internal issues?

[kkinzli]

I am thinking it had to be some internal issue

[Joe Bob]

Under warranty? Would be interested in what failed. IF they would tell you is another matter.