Karl, thanks for the clarification. Let me clarify my take on loading the parts catapult. It always include the exclamation: Pull!

When I load the parts catapult it indicates that I haven't done adequate troubleshooting, either I don't know how or am lacking the proper istrumentation or money to purchase said tools and or equipment. I might even be flat out guessing without a clue all the way up to a good educated guess.

When proper testing and evaluation of the problem points to a specific part I do not consider that part purchase to be loading the parts catapult.

 

At times I dont see anything wrong with buying all the parts so you have them at hand when working on said thing so you dont have to keep stopping to go get them.
I do have a little clue what the cause might be when checking but it could lead to more then 1 part being bad.
Kind of happened when I had a miss under load. I ended up doing a full tune up, pickup coil and main coil change and a carb change, I had the carb on the shelf.
Dave ----

 

Well, troubleshooting is just like my ethical standards. Basically, it's situational.

(Pause for laughter to die down)

I often joke about loading the parts catapult (Pull!) in lieu of actual troubleshooting, but there are several factors to consider. In no particular order:

Is the part difficult to change?

Is the part expensive?

Is the part a normal consumable item (i.e. a fuel filter or distributor cap) that gets changed as routine preventative maintenance anyway?

Let's say you're getting a light chugging at freeway speed and you suspect a fuel delivery problem. Changing the fuel filter would be a reasonable guess. In theory, one could rig up a fuel pressure gauge, make some test runs, and then probably end up changing the filter anyway. In a simple case like that, going straight to a filter change is a good course of action. The part is cheap, easy to replace, and is intended to be changed on a regular schedule. If that doesn't fix the problem, trying a fuel pump might even be a good idea. Still fairly inexpensive, easy to change, and they certainly don't last forever. But that's about where I'd draw the line of shooting from the hip. If a new filter and pump don't fix it, then it's time to investigate further. I suppose if you had a known-good spare carb sitting on your shelf, you could try that, but I certainly wouldn't spend several hundred dollars on a reman just yet.

The preceding example was all fine and dandy. But sadly, how many times have we seen examples of catapult (Pull!) usage like the following?:

The engine won't start, so the battery gets replaced. Hmm, that didn't do it, so back to the store for a $79 starter with a lifetime warranty. It must be good if guaranteed forever, right? Hmm, still no joy. How about a new starter relay. Still no workee. Maybe it's bad spark plugs and wires? How about a distributor cap? We've change all the electrical parts. Could it be the carb? And so it goes... We can laugh, but it is VERY common for guys to throw all sorts of expensive parts at a problem in hopes of a fix. Meanwhile, the original problem still exists, but with the added likelihood of introducing a new fault with all that frantic parts swapping.

Wish I could find the study, but I remember a college class (Univ of Colorado?) did a controlled blind test of local mechanics. This was the late 70s, IIRC. (My brother knew the people who ran the study.) They used a VW Beetle, a common car at the time. They deliberately loosened the alternator drive belt, which is a simple, common fault. With the belt slipping and the charging system not up to par, the battery slowly ran down. The only visible symptom was slow cranking of the starter. A student brought the car to various mechanics and reported only that the car was hard to start. In return, they got all sorts of diagnoses. About half of the shops correctly diagnosed the loose belt and the resulting low battery. The rest wanted to change the battery, starter, etc.

 

I do IT for a living and people's ability to take a step back and worth through the symptoms before flying off half cocked is incredibly variable. Twice a month I have to talk someone down from making some drastic change because they latched onto the idea it couldn't be a simple problem out of the gate.

 

wow this thread went off topic

 

I guess that's what happens when old guys have to much time on their hands...right Karl ? LOL

 

Us old guys are trying to keep it alive and not pushed to the bottom of the page
Beside you cant teach us new tricks
Dave ----

 

What you've got there is called a Trebuchet, not a catapult. A far more fun word to say, for sure, at least as fun to say as it would be to operate.

https://en.wikipedia.org/wiki/Trebuchet

 

I was wondering when the French would arrive....

Also yes, sometimes throwing parts at the problem can work good, hell a broken watch is right twice a day. Don't forget that these old girls are simple creatures, need 3 things to make go. Start with your fire triangle and work out the systems from there. Oversimplification, sure but that's part of the fun, Occam's Razor works better then any Gillette I've owned over the years. Need a easier metaphor, fine I have those in stock as well... Use the KISS system - Keep It Simple Stupid, would hate to create a ID-10T code while digging into the wrong system.

Secondly, a notable mention for brakes, when replacing calipers for whatever reason, take a hard look at the rubber line, or consider replacing with it. Adds $40 to brake job per wheel, but what happens is part of the inside of the line will brake away and create a check-valve in your line, allowing fluid to apply but not return, leading to premature pad wear. On the same system, brake fluid is hydroscopic, it will pull moisture from the air. Water and hydraulic systems don't mesh well, so every couple of years think about flushing the lines and getting new fluid in there. Using the Gatorade bottle bleeder just bleed off / replenish with new, until you get good fluid at valve.

 

I cannot believe I've lived my entire life and never heard that code. Brilliant.

 

http://— I.D. 10-T or ID10T is an al...e more or less

 

Yep. Even more, the lives of those around me improve exponentially when exposed to my rigid, unyielding opinion on everything. For the benefit of mankind, it's a service I provide for free...