Tech To Tech
The Battle Between Pride And Profit
This is a tale of woe from a shop in Tucson, Ariz. The shop is very well-managed and staffed by highly qualified technicians. This repair occurred a few years ago and I was a party to only a portion of the repair. I will try to relate this story as I heard it and hope that all of the facts are correct. This repair serves as a good example for the point I’m attempting to illustrate.The car was a late ’80s Tempo with a worn out 2.3 liter, High Swirl Combustion (HSC), Throttle Body Injection (TBI) engine. Despite the limited value of this car, the owner wanted the engine replaced. After being given all the options, the customer opted for a Ford factory rebuilt engine because of the faster turnaround time and longer warranty period. Estimates were agreed to and everyone was happy.
The Ford rebuilt engine even came with manifolds installed. This looked like a quick swap. The installation went as smooth as silk all the parts matched perfectly. Everything was fine until the test drive. The car idled well and ran smoothly, but seemed to have only half to two-thirds the power it should have. The first suspect was a plugged exhaust, but a pressure test on a test drive revealed no problem. Later, even dropping the exhaust pipe had no positive effect. A self-test revealed no codes ... no big surprise here. Ignition on the scope looked good, cylinder balance was good, exhaust gases were good, and fuel pressure tested OK under driving conditions. Timing and advance were tested and retested OK. The injector pattern was good. Compression tested good.
I’m sure I have left out dozens of other tests that were run to no avail, including new fuel, just to be sure. Now this job slipped into a quiet desperation mode I think we can all relate to. It’s the car that is no longer a primary repair. You come in in the morning and assign the cars that will be repaired that day, then, when all the primary work is done, this secondary job sucks up your spare time. This is the car that might get two to three hours of work a day and other days may be ignored altogether. Some jobs you just have to get away from to keep your sanity.
Then there’s the second phase of desperation throwing parts at it. Hey, I’m not being critical here. As it’s been said, "Let he who is without sin cast the first stone." I think we have all been there. I believe the parts included a computer, a throttle position sensor, a coolant sensor, a MAP sensor, a coil, an injector, and a fuel pump. Ouch!
Well, the profit in this job was lost a long time ago. Now it became a case of just trying to salvage as much money as possible and cut the losses. However, the customer was unwilling to part with a penny until his car ran right; can’t blame him because this was a case where it truly "didn’t do that" before it came in.
Phase three of this ordeal then began, which is where I came into the picture. No self-respecting shop owner wants to tuck his tail between his legs and admit defeat, but sometimes you get so buried in a job, you may not be able to see the forest for the trees. The shop owner recognized he was at an impasse, and the car was delivered to me with carte blanche.
Respecting this shop’s abilities, I accepted for now that basics were OK (fuel pressure, exhaust flow, timing, etc.). I went right to a full blown Simu-Tech checkout. All grounds tested OK, all power supply was OK and no alternator diode problems. Fuel injector pattern was normal and pulse width was normal. Exhaust gases checked out OK. All sensor inputs normal, except MAP frequency was higher than normal at idle! The MAP Hz was 159 with the key on, engine off, which is normal. Besides, a failing MAP sensor usually reads lower than normal. A test of engine vacuum showed the MAP signal was correct; it was the actual engine vacuum that was low.
I called the shop owner for more information. Had the timing marks been confirmed against the true TDC of the piston? What about cam timing? He said they had been checked, but he wanted to pay me to double check. I was surely going to be a hero today! No dice on the ignition timing, the marks were correct. I was sure the problem was internal to this engine. After all, the problem didn’t exist before it was installed. I had too much respect for this shop’s expertise to start double checking all their other work. I had complete confidence that no problem existed in the computer system and that is what I had been hired to eliminate. I got paid, and when the car left, I breathed a sigh of relief that I wasn’t married to this one! Small satisfaction, but still a good friend was stuck with this headache and I wanted to know the conclusion. Was my diagnosis correct?
The cam timing was double checked at his shop and unless the marks were wrong, it was correct. Now for the fourth and final stage of desperation that I also agreed was the best step at this point drop it off on the Ford dealer’s door step that supplied the engine and tell them to fix it! If you find fault with any of our work we will gladly pay! Ha! Lowly independent fools, you will pay dearly, thought the dealer! And so started a landslide of parts. New computer, all new sensors, all new ignition system including distributor, new throttle body assembly and new harnesses. I can’t remember it all, but needless to say, no fix! And two more weeks had been wasted, besides the month that we already had burned up.
The Ford dealer finally relented and installed another rebuilt engine. The beast from hell was not to be satisfied! The problem persisted! One of the Ford techs, while pondering the situation, was looking at the engine that had been removed and noticed that the head had small, square exhaust ports, but the carbon shadow around them was large and round. As it turns out, this engine was produced in HSC and conventional combustion chambers. The exhaust manifolds are internally very different, but externally have the same dimensions! Remember, this engine was delivered with manifolds! The wrong exhaust manifold was disturbing the high swirl combustion process, creating the low power problem. Had this engine been a normal long block without manifolds, this problem would have never occurred.
The point is that there is always an alligator out there ready to eat your lunch no matter how good you are! Sometimes while he’s munching your lunch you may have to make a determination between pride and profit. Of course, just like the gamblers that we are, we’re all sure the next hand (next test) is going to be the big score. In my shop, we take great pride at our ability to find complex problems, but for us, we have to question the logic of continuing when three to five hours of time has been spent to no avail. We don’t charge if we don’t fix a car. However, we bill very well if we do. So the customer’s willingness to continue has to be determined. Keep in mind that the case of this Tempo was a hard fault intermittents may call for declining a job before even starting. (See AutoInc.’s July 1995 Tech to Tech column for more information about dealing with intermittent problems.)
The shops in the example above got sucked in and were married to this car by factors beyond their control. They didn’t have the luxury of just bailing out. Most problems can be solved, but if you’re in way over your head with no end in sight, sometimes you need to be honest, bury your pride and hit the eject button. Even Napoleon had his Waterloo.
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AutoInc. Magazine ®, Vol. XLIV No. 2, February 1996