18 November 1998

TECH TIPS

Tech Tip

winners

are selected

monthly by

the editors

of Import

Service and

the

NAPA Echlin

technical

staff.

Tech Tip

winners

are selected

monthly by

the editors

of Import

Service and

the

NAPA Echlin

technical

staff.

Winning Tech Tip entrants will receive $100 from NAPA Echlin, except

for those Tech Tips appearing in the March Tech Tips Special. The

authors of Tech Tips appearing in the Tech Tips Special will receive a 12-

function collapsible pocket tool from NAPA Echlin. A cash prize of $2500

will be awarded to the entrant submitting the best 1998 Tech Tip. You

may also submit Tech Tips online at <http://www.gemini-comm.com>.

This month’s Tech Tips pages are the first to contain electronically sub-mitted tech tips. Several techs have pointed their browsers to the Internetaddress listed above and we have printed their tech tips here. We won’ttell you which tips are electronic and which are “paper-based.”

If the idea of receiving a $100 check in the mail still gets your heartpumping a little faster, crank up you computer and get to work. We’relooking forward to hearing from you.

Some 1992-93 Acura Vigor models may exhibit hesitation and stum-bling symptoms, along with setting a PGM-FI Code 4. Don’t be tricked intocondemning the Crank Sensor, PCM and/or the wiring harness.

To properly diagnose these symptoms:• Disconnect the four-pin green connector from the back of the alternator.• Reset the PCM, then test drive the vehicle.• If the symptoms go away reconnect the alternator.• If the problem returns, repair or replace the defective alternator. Voltagespikes from a defective alternator can interfere with the Crank Sensor signal.

Kevin LozaMaster Tech Auto CareBellflower, California

There have been many charging system problems on late modelNissans that are equipped with the company’s new-style alternator.Every unit that I have seen in the last six months has had the same prob-lem: stuck alternator brushes.

The only way to fix this problem is to replace the brushes. Remove theunit for disassembly. Remove the brush holder and the old brushes. Usea scribe to remove any irregularities from the brush way inside the brushholder. Install new brushes and springs (if necessary) and reassemble.

This may sound like an easy fix, but it can be a huge hassle if you don’tknow what you’re looking for.

William KarrValley West Auto And Truck ElectricArcata, California

Editor’s Note

Don’t Be Misled

Nissan Charging System Symptoms

19November 1998

Any Isuzu Rodeo, Amigo or Trooper equippedwith a 4ZE1 (2.6 liter) engine may exhibit a low idlespeed and surge on warm restarts. The intake gasketsare prone to leaking, especially near the number 4cylinder and cause the MAF sensor to deliver thewrong input to the ECM. Additionally, a very lowidle speed on a warm restart may be due to a ther-mostat with the wrong temperature range.

The TVSV on top of the thermostat housing isdesigned to open and boost the idle speed in theevent of overheat, thus increasing the water pumpflow. Too high of a temperature thermostat mayincrease the base idle speed with the overheat TVSV,and if the air bypass screw is adjusted at this time,the next restart idle speed may be after the overheatTVSV has closed, causing a very low idle speed.

To inspect, fully warm the engine and restrict thevacuum hose running from the TVSV and the intakeducting. If the engine slows, chances are a thermo-stat with the wrong temperature range was installed.Always inspect for basic overheat conditions, just tobe on the safe side.

Start taking notice when servicing NissanPathfinders and Pickups equipped with the VG30Eengine. We have notice many of these models show-ing their age. The fan hubs and blade supports arecracking and should be replaced at once, before anydamage or injury can occur.

When lifting a Mitsubishi Montero or Dodge Raider,be very careful if you are using a frame contact hoist.When the tires leave the ground, the unsupported rearaxle drops far enough to cause the flexible rear brakehose to suspend most of the rear axle’s weight. A dam-aged rear brake hose might not be immediately appar-ent, but a later failure could result.

If a frame contact hoist is your only method of get-ting one of these vehicles into the air, a chain mustbe attached to the undercarriage, wrapped aroundthe axle, then back up to another attaching point onthe undercarriage. This limits the axle travel whenlifted into the air. (This must be done while the vehi-cle’s suspension is still in a loaded state on theground.) Following this simple precaution will keepthe rear brake hose from getting strung as tight as apiano wire, and possibly snapping while the vehicleis in the air!

Brad PetersenJon Woods AutomotiveSan Diego, California

Several manufacturers recommend the use of largemetal stationary binding clips to hold the timing beltin position when installing a new timing belt. Thebinding clips are clipped to the timing belt on oneside, and the timing sprockets on the other. Theseclips are necessary because the camshaft(s) mayhave a tendency to jump out of position while thebelt is being moved into position. Movement of thecamshaft sprockets is caused by the spring pressureof partially opened valves. When the timing belt isremoved, the valves will want to close and thesprockets will turn.

After getting my hands and fingers smacked severaltimes using this method on several single and doubleoverhead cam Nissan and Mitsubishi engines, I decid-ed to find a better way. I now use plastic tie wraps tohold the timing belt in position as I work it into posi-tion around the timing belt sprockets.

Before you start, get as many timing marks as pos-sible lined up, then start working in a clockwisedirection to slip the timing belt into position. Whenyou get to a timing sprocket, make sure the timingmarks are lined up, then hold the timing belt in posi-tion with a tie wrap. When you have the timing beltcompletely installed, try turning the crankshaft for-ward and backward several degrees before recheck-ing you timing marks. When you are sure that every-thing is lined up properly, remove the tie wrapsbefore turning the crankshaft two complete revolu-tions. Now recheck your timing marks. If you did thejob right, you’re half way home with no rappedknuckles to show for your trouble.

Jose CamposB.C. Auto RepairBronx, New York

When the timing marks are lined up, opened valves maygive the cam sprocket the urge to turn at an inopportunemoment. Temporarily link the timing belt and camsprocket using a tie wrap through the sprocket holes.

Idle Speed And Warm Restart Woes

Nissan VG30E Fan Blades

Mitsubishi Montero Lift Warning

Be Safe