22 February 1999

TECH TIPS

Tech Tip

winners

are selected

monthly by

the editors

of Import

Service and

the

NAPA Echlin

technical

staff.

Authors of published Tech Tips will receive $100 from NAPA Echlin. A

cash prize of $2500 will also be awarded to the entrant submitting the

best Tech Tip of 1999. Use the attached Tech Tip card, or you may also

submit your Tech Tips online at www.gemini-comm.com.

Jose Campos wins the con-test for best tech tip of 1998 forhis simple but clever suggestionin our November issue on how touse plastic cable ties to preventcamshaft timing sprockets fromfalling out of position on themore complex timing beltreplacement jobs. His sugges-tion uses ‘outside-the-box’thinking to solve a problem man-uals and other technical infor-mation don’t address or requirescarcely available special toolsto solve.

Mr. Campos comes from hisnative Puerto Rico and works forHunt’s Point Auto Parts in NewYork City, a supplier as well ofrecycled automotive compo-nents. His current work disman-tling cars as parts-donors willprobably serve him well in whathe’d like to do longer termbecause of the practiced speedhe’ll master.

Mr. Campos’ ambition is to achieve what many readers of this maga-zine have done themselves: to establish his own repair shop, probably inThe Bronx. He is in the process of obtaining a New York license for thatpurpose and saving his resources to set up the business. Hopefully hiswinnings from the Tech Tips contest will let him buy some tools or stocksome inventory that he otherwise wouldn’t. We wish him the best of suc-cess and confidently expect to drop by his shop for a visit in a few years.

The tech tip he sent us well illustrates the kind of thinking that cansolve unexpected problems in novel ways. Can you recall solutions toproblems that made you shout “Eureka!”? Be sure to send them in – if weagree, you’ll see $100 for each one published, and if yours is what wethink is the year’s best you’ll take home an unexpected $2500, as JoseCampos did.

1998 Tech Tip Winner

Jose Campos1998 Tech Tip Winner

23February 1999

Here’s a quick fix for a Nissan Sentra or Pulsarmodel equipped with a chokeless Hitachi carbure-tor. If the engine won’t idle or has an off-idle hesi-tation, first determine whether the fuel cutoff sole-noid is functioning as it should. The solenoidshould block fuel flow only when the key is OFF. Ifit does, proceed as follows:

• Turn the ignition OFF.• Spray carburetor cleaner into the air bleeds locat-ed in the primary venturi side of the carburetor.• Swap two spark plug wires at the distributor cap.• Hold the throttle open slightly, then attempt tostart the engine.• The engine should backfire through the intakemanifold and carburetor, dislodging the debris fromthe idle circuits. • Turn the ignition OFF, reinstall the plug wires intheir proper location, then attempt to start the engine.

If your intentional backfire has done its job, theengine should idle properly. If not, it’s time to sellthe customer a carburetor overhaul to root out theidle circuit debris.

Mike HinesCarburetor Specialist (the last of a breed! —ed.)Marietta, Georgia

Be sure to replace the cam belt tensioner during atiming belt replacement on 2.0 liter DOHCMitsubishi engines. The original tensioner may faillater, causing expensive engine damage.

Thomas “TC” CrossTom’s Auto ClinicKittridge, Colorado

Have you come across Honda or Acura vehicles withbrake calipers that stick or lock for no apparent reason?We specialize in the repair of Honda and Acura vehi-cles and have identified two possible causes.

First, you may not be aware that two different reardisk brake systems have been installed on thesevehicles. One incorporates the parking brake func-tion into the rear brake caliper, while the other usesa small drum brake setup inside the rear rotor.

Problems arise when a shop uses the rear brakepads designed for one parking brake system on avehicle equipped with the internal drum parkingbrake system. Pads designed for vehicles with thecaliper parking brake system have a short pin on theinboard pad. This pin is supposed to lock into placein one of four notches in the caliper piston. Lockingthe pad to the piston keeps the piston from rotatingand assures proper parking brake operation.

The trouble starts if a pad with a pin is installed ona vehicle with an internal drum brake parking brakesystem. The rear caliper pistons on these systems donot have notches, so the brake pad can’t sit squarelyin position. The pad cocks to the side, which maycause the brakes to stick or lock up at that wheel.

Do not install pads without pins on a caliper thatneeds them, or the parking brake can’t adjust as thepads wear. And don’t install pads with pins oncalipers without the slotted pistons. Send themback and get the right pads.

The second problem concerns front brake padshims. Incorrectly installed shims allow the brakepads to cock to one side. This causes the same stick-ing or lockup problems. Repair or replace any brakehardware as necessary to correct these symptoms.

Steve KirganThe Honda MenCopiague, New York

According to this diagram of the chokeless Hitachi carbu-retor air bleed circuits, the slow air bleed orifice is con-

nected to the idle circuit. Direct your carb spray here first.

This diagramillustrates thepin-type rearbrake pads

used on vehicles withcaliper-actu-ated parking

brake sys-tems. The pinmust engage

one of thefour slots.

Nissan Intentional Backfire Cure

Tension Please!

Honda Brake Pointers

23 N•m (2.3 kg-m, 17 lb-ft)

INNER PAD SHIM

Rotate.

PROJECTION

Main air bleed

Slow air bleed

Slowdown channel Main jet

Solenoid controlledslow air bleed OPEN

Solenoid controlledfuel orifice CLOSED

Air fuel ratio solenoid