Mazda Club Tech Tips for all year Mazda cars and trucks

North America's oldest and largest club for all Mazda cars and trucks!! Established in 1988

WELCOME TO THE MAZDA CLUB
of North America
for all year Mazda cars, SUVs and trucks
Established in 1988

P.O. Box 11238
Chicago, Illinois 60611
Ph.: 773-769-6262
Fax: 773-769-3240
email: info@mazdaclub.com

Home Officers Articles Tech Tips Membership Benefits Ads/Links Join /Renew - Application Membership Items Email Classifieds Vehicle Photos News/Editor Club Store Message Board/Blog Ad Rates Credit Card/Payment Form Members Only

TECH TIPS

Technical tips, advice and shared Information.........That's what this page is all about. This is only a very small part of the tips that appear in each issue of the member magazine.

There are also more tech tips and member recommended repair shops in the Members Only area an our TECHNICAL STAFF is prepared to answer your technical questions. See contact information in the Members Only area.

A complete copy of all the Technical Sections, topics, questions and answers published in the OnlyWay from 1998 to 2007. Available on CD-Rom only for PC or Mac in pdf format. It sells for $ 10 plus $5 S&H and is indexed by subject for easy reference and contains articles, topics, questions and answers. It is available in the club store.

More items in the tech section of the club Message Board at
board.mazdaclub.com

Order Mazda RX-7 ('86 - '91) Repair Manual
Order Chilton's Mazda 323/626/929/GLC/ MX-6/RX-7 1978-89 Repair Manual
Order Chilton's Mazda 323/MX-3/626/Millenia/Protege 1990-98 Repair Manual
Order Mazda Miata MX-5 Enthusiast's Shop Manual

Questions and Answers

Please note: Questions and answers are provided for information and advice purposes.

No liability either express or implied is assumed by reliance on the information presented either by the writers or the MC. Some or all of the below is from our message board at board.mazdaclub.com .

Also be sure to see our message board for more immediate answers at board.mazdaclub.com..

Enter your search terms Submit search form

Web www.mazdaclub.com

Q: I’ve noticed that on a hot day, when my A/C is ON, my car, a 2000 Mazda 323 sedan stops accelerating, the check engine light occasionally comes on. As the car starts to accelerates, after a few minutes, the check light eventually goes OFF. This problem does not occur at night or on a cool day.
I’ve replaced the air filter and spark plugs, and a diagnostic was done on the vehicle while the light was ON, and no problem code came up.
Any suggestions?

Sadiq Mohammed

Q: My 1992 626 2.0 was set at high RPM (2000) at rest for years. I instructed my mechanic to lower it to improve fuel consumption when he replaced an over heated engine. The car stutters when RPM is lesser than 2000 ever since. The Mazda computer blames the distributor; that was replaced along with it’s wiring, to no avail.

Please no lemon law suggestions my sister is the previous owner the one before is her friend, the mechanic is my friend.

Avi

Q: I think your mechanic may be a better friend than a mechanic
2000 RPM is way too fast for idle. Set the idle back down to where it is supposed to be.

Scrotege

Q: Can anyone give me an idea what causes the check engine light to come on in a 2001 Protege, 2.0 engine. I have put on a new air filter, the gas cap is tight and in good shape. It has 77,110 miles on it, mainly freeway driving at 65-70 mph, 125 miles per day. It runs great!

RX8Man1978

A: If you take it in, they will tell you it’s the O2 sensors (even when it’s not). I’ve had a 1995 Protege, 2000 MPV, and 2006 MPV and they ALL have had problems with the check engine light. I’ve finally learned to ignore it and in a few weeks, it will go off by itself.

TN-MPV

Coaximg More Power out of Dr. Wankel's Fascinating Engine
by Douglas Kott

It looks like nothing else that was ever bolted to a transmission’s bell housing — a chunky little cask made of alternating slabs of cast iron and aluminum, housing two triangle-shaped rotors that orbit an aptly named eccentric shaft. It’s otherwise known as Mazda’s Wankel engine (with the 12A variant powering our 1983 RX-7 project), and it’s what makes the RX-7 the most commonly raced car in the Sports Car Club of America’s Improved Touring A class.

Why, you ask? First, the Wankel engine itself is simple—gases move into and out of the combustion chambers through ports; no moving valve train parts mean no pushrods to bend, no rocker arms to snap, no valves to bounce off the tops of pistons. Consequently, they tend to tolerate the occasional overrev better than their reciprocating cousins. Wankels also have a reputation for longevity — a well-maintained engine can be raced for three or four seasons without a rebuild. Let’s not forget that the Wankel’s handy carrying case won’t break the bank, either — a 1979-1985 RX-7 can be found for less than $2000, almost cheaper than dirt. And heck, with the Wankel’s being the winningest engine in IMSA history and a 4-rotor version’s having won at Le Mans in 1991, the rotary has the sort of competition pedigree that evokes warm images of Moet-soaked podium finishes and waving checkered flags.

With no budget for a fresh engine, we’d have to make do with our car’s original 12A, a "well broken-in" example with just over 100,000 miles of service. It still ran strongly, didn’t smoke much and didn’t consume excessive amounts of Castrol’s finest 20W-50.

There was, however, lots of oil and crud on the outside of the engine and transmission, so we thought a logical starting point would be to pull the whole mess out with a cherry-picker hoist and clean it up as much as possible with multiple cans of Gunk degreaser, a scrub brush and lots of paper towels.

That accomplished, we replaced the engine’s front and rear main oil seals, the oil pan gasket and the transmission’s main seals, a move to delay repeating the entire de-crudding process for as long as possible. Seal removal and replacement is straightforward enough, prying out the old pieces with a big screwdriver and tapping the new ones in gently with a hammer; but getting access to the engine’s rear seal is more complicated — the flywheel, held on the eccentric shaft by a huge gland nut that’s torqued to about 350 lb.-ft., needs to come off. You’ll need a special wrench that looks like a Land of the Giants prop (its bar-stock handle is nearly 3 ft. long!), as well as a means of immobilizing the flywheel, to break it loose.

With sunlight now glinting off the engine’s freshly scrubbed castings, we got down to the business of extracting more power in a racing class with a rather narrowly written set of rules. The largest gains are to be had with a less restrictive exhaust; to this end, Racing Beat provided us with an ideal "street port" system ($568.00 complete) consisting of a header, two pre-silencers and a Prima Flow main muffler in the stock location. Made with a 716-in. header-to-engine flange and 2.0-in.-diameter thick-walled steel tubing, this bolt-in system is designed to handle the rotary’s extreme exhaust temperatures (up to 2000 degrees Fahrenheit under full throttle and high load, versus maybe 1400 for a piston engine). And though IT class rules don’t allow for power the cheap and easy way (i.e., porting), the "street port" system works very well for non-ported engines too. Key to its design are primary tubes that run nearly the length of the wheelbase, merging just before entering the main muffler at the rear. The effect here is to keep each rotor’s exhaust pulses separate until the last possible moment, thereby increasing the scavenging effect and producing more power, especially at high revs. How much? Perhaps 25 bhp, bringing our total to about 125.

With exhaust fitted, our attention turned to induction, but first we removed the complicated web of emissions-control valves and vacuum lines, many of which connect to fittings in a plate at the base of the stock 4-barrel carburetor, fittings that need to be plugged with caps available at any auto parts store. The air injection pump and its associated hoses and clamps can be taken off at this time too, along with the check valve that bolts to the side of the intake manifold (the resulting hole is neatly capped with a block-off plate made by Racing Beat).

The rules permit updating and backdating of parts, and we learned that the intake manifold from a 1979-1980 RX-7 flows the best, because it lacks what’s called the "shutter valve" that helps prevent backfiring on deceleration. Willing to trade a little backfiring for better flow, we obtained a 1979 manifold from Dave Lemon of Mazdatrix, who, in addition to building street and race Wankels and offering a full line of hop-up parts, has a pretty good inventory of used spares.

For 12A RX-7s, the stock carburetor must be retained, but can be rejetted (we left the primary jets stock, but changed the secondaries from 160s to 175s, those numbers corresponding to orifice diameters measured in hundredths of a millimeter) and can be stripped of any emissions-related devices. We removed the choke butterfly and shaft to improve airflow, and plugged the resulting holes by hack sawing the shaft in two, mushrooming the ends with a hammer and reinserting each piece from the outside of the carb. A blob of silicone sealant on the shafts makes the whole setup airtight. The last internal carb change was to replace the stock needle valves in the float bowls with ball-type valves (called "Grose Jets," about $7 apiece, from Mazda Competition Parts) that are said to better maintain the fuel level under racing conditions.

With larger jets admitting more fuel, we thought the stock fuel pump (underneath the car, just ahead of the rear axle) might be overtaxed, so we installed a 6-psi Facet fuel pump ($41.00, from Racing Beat), plumbed in parallel, to ensure adequate flow. And in case this proved to be too much pressure, a Purolator fuel-pressure regulator ($15.70, from Racer Wholesale) was spliced in near the carburetor.

Capping off our carb (literally) is Racing Beat’s Power Pulse air filter assembly ($50.00), made of powder-coated spun aluminum with a washable foam filter element. While this element offers no improvement in airflow over a clean, stock paper element, its flow isn’t impaired by significant amounts of dirt—something that can’t be said about the stock element. And while cleaning and re-oiling the foam is a messy, disgusting job, it certainly beats buying a new paper element every two races!

We’re down to finishing touches now. A set of low-resistance Race Ignition Wires ($93.00, from Racing Beat) adds a bit of color and undoubtedly a hotter spark, and is the only deviation from the very robust stock electronic ignition system that was introduced on the 1981 RX-7. Make sure that the cap and rotor are in good condition. For cooling, the stock radiator will suffice for IT racing, provided it is relatively corrosion-free (luckily, ours was). But you’ll want to remove the thermostat and plug the water pump’s internal bypass, which we accomplished with a large-diameter bolt (hacksawed down to about 12 in. in length) and copious amounts of JB Weld, an incredibly strong 2-part epoxy/metal compound available at most auto parts stores. The cooling fan? We tossed it, knowing that above 30 mph or so, ram air dissipates more heat than the fan ever could. We’ll just have to keep an eye on the coolant-temperature gauge if we do any extended jockeying around in the pits. As a last nod to improved cooling, we replaced the stock drive pulley with a special small-diameter one (about $60, from Mazda Competition Parts), which spins both the water pump and alternator more slowly. This reduces water-pump cavitation—air whipped into the coolant, the bane of effective heat transfer—at extended high rpm and frees up a bit of power as well.

So what we have is a strong-running but high-mileage 12A Wankel that is fluid-tight, clean and makes perhaps 135 bhp. To make sure it remains together for as long as possible, we installed a 10,000-rpm tachometer and oil-temperature and pressure gauges (retail priced at $131.90, $89.25 and $55.75, respectively) supplied by Auto Meter to monitor vital functions. The tach mounts to the steering column with a hose clamp and special bracket, but we went the extra mile to showcase the other gauges. Staff composites guru (aka Road Test Editor Kim Reynolds) laid up a nice sheet of carbon fiber that we trimmed, filed and drilled for a center-console gauge panel, which also houses pull-knob switches for the lights and wipers, a starter button and an electrical-system continuity lamp. The brushed-aluminum bezels and faces of the Pro-Comp Ultra-Lite-series gauges play nicely off the dark carbon fiber, making for a semi-exotic yet functional finishing touch.

As you may have deduced from this story, our RX-7, resplendent in its freshly applied, zippy paint scheme, has already sampled its first taste of racetrack, putting yours truly through SCCA’s competition school at the Streets of Willow circuit near Lancaster, California. With Novice Permit in hand, I’ll keep you posted in About the Sport on how our project car fares in actual competition

RX-7 SHUTTERING ENGINE
Terry Mosby

The engine in my 1991 RX-7 would act as if it were going to stall and rpms would fluctuate wildly. The dealer did not know what was causing the engine to act this way. About a month after this started the engine died.

It lost compression in the first chamber with only 80,000 odometer miles on it! So I just wanted to let my fellow RX-7 owners know that if your engine starts to shudder and stutter get the compression checked out. I was unaware of this compression problem that plagues RX-7s.

The dealer told me that the rebuilt engine is good for another 100,000 miles. Needless to say, I did not get that much out of the other one. However, I have owned two other '82 RX-7s and I got over 120.000 miles each on those engines.

TRANSMISSION SERVICE
Mike Martinez, Martinez Motorsport

How often should you change your vehicles transmission fluid? While most manufacturers recommend changing the fluid every 30,000 miles, I have slightly different thoughts. For starters, the key to a long and healthy transmission life consists of one thing - clean fluid. Once a transmission fluid becomes dark brown or black, its days are numbered. Transmission fluid should ideally be a transparent pinkish red. When it becomes too dark, this is a sign that the clutch plates are wearing away and blending in with the transmission fluid. Think of a piece of sandpaper. If you rub a piece of sandpaper against something, the grain wears away. This is what a clutch plate in a transmission is similar to. Once that grain wears away, not only will the transmission fluid discolor, but the transmission will eventually begin to slip.

The key to keeping the transmission healthy is to keep that fluid clear! My personal recommendation for accomplishing this is to change the transmission fluid every 20,000 miles up to 60,000 miles, then change it every year. This will insure that the fluid remains clear and will most importantly extend the life of the clutch plates. A transmission service every year is about $60.00. A new transmission will cost about $3,500 installed.

One other point of interest. The majority of late model vehicles use a screen as a filter. This screen can usually be cleaned out and reinstalled. Most vehicles also have a drain plug which allows the fluid to be drained without removing the entire transmission pan.

ROUGH IDLE
Brad

If you are having a problem with rough idle do the following:
First I would go through the entire ignition system. Starting with the spark plugs, then the wires, then the distributor and distributor cap, then the coil.
Second, check and replace everything that isn't pretty new. I would go ahead and replace the plugs and wires and put in a new air filter. This can't hurt and will eliminate some variables. I would also clean my battery terminals.

QUESTIONS AND ANSWERS

Q: What is a throttle body, and why do I need one? I took my 1993 626 for its annual state emissions inspection, but the garage couldn't perform the diagnostics because the car was idling too fast. I then took my car to the dealer and had them check out the idle.
They told me that my throttle body was shot, but they could get me a new one for $1,000. However, they were able to adjust the idle so I could pass the emissions test. My car seems to be running fine. So, I am asking you, what is a throttle body, and why do I need one?
Cathy

A: The throttle body is the throat through which the air passes when you step on the gas pedal. And it costs $1,000 because it's a finely crafted and machined piece of. . . well, cheap aluminum.
What happens to them is that the throttle plate, the steel "flap" that lets air in, wears a groove into its aluminum housing or "body." Too much air is allowed to get through, even when the throttle plate is closed. So it's as if you have your foot lightly on the gas pedal, even when you don't. What the dealer did was adjust the air bleed screw, which cuts down the amount of air getting through to the cylinders at idle. That returned your mixture to a more normal setting and allowed you to pass the emissions test.
But eventually this will happen again. And there's only so much adjustment in the air bleed screw. Eventually they won't be able to turn it anymore, and then you'll need a new throttle body.
So ask your mechanic how many more turns you've got left on that air bleed screw, and that will tell you how much time you have - to either save up for a new throttle body or unload this car on" co-worker you don't like.

Q: I drive my 1996 Mazda Millenia about 20 miles a week in three days. All of this driving is done on city streets (Chicago).
What if those miles were driven in low and second gear, to keep the r.p.m.'s up? Running the engine on high r.p.m.'s heats the fluids faster and is more likely to boil off condensed water in the oil and muffler system. The Millenia's 4-speed automatic transmission allows the driver to operate only those two gears. Thank you for your insight.
Nancy Donahue

A: If most of your driving is in slow city traffic, your engine and transmission fluids are probably warming up if and the water in your exhaust system probably cooking off. We would not advise driving continuously in lower gears because this can overheat the transmission fluid and lead to premature wear. Just remember to change your fluids according to the more frequent schedule in your owner's manual.

Q: I have just purchased a 1988 Mazda RX-7 GXL with 1 115,000 miles on it. Most people consulted, including a dealer service manager, said the rotary engine is good for only about 100,000 miles before needing a rebuild. My engine burns no oil that I can see, including during engine braking. What are the symptoms of rotary engine failure? What can I do to keep what is now a good engine in good condition?
John Kissinger

A: Rotary engines are inherently simple, and aside from giving them normal care, there is no special maintenance required. Of course, the easier you drive a rotary, the longer it will last, just like a piston engine.
Loss of compression past the apex or side seals is the main trouble with high-mileage rotaries, according to our research. Typically one apex seal goes, causing low compression and hard starting. Because each rotor gives three distinct compression pulses for each rotation, low compression from a bad apex seal is often heard as uneven cranking speed.
Compression testing will show poor apex seals, too. Rotary technicians favor a special, tracing compression gauge, but a standard dial-indicating gauge is still useful. Hold the release valve open while testing to observe the needle's free movement, an pay special attention to comparing the results from one rotor to the second. They should give equal readings. Remember, there will be three pulses per rotor revolution.
Two weak an one strong pulse are typical for a bad apex seal. Leaking side seals show as just one weak stroke and two strong ones.
On 1993 and later Mazda rotaries, any vacuum reading below 18 in. of idle vacuum is reason to suspect the rotor seals.
On all rotaries, smoking through the exhaust during deceleration shows the oil consumption rings are going bad. The oil rings seal the rotors to the shaft. They are necessary because thee rotors are internally bathed in oil for cooling purposes. Also, earlier engines will blow exhaust into the cooling system when overheated, so check for bubbles in the radiator.
Finally, some rotary racers claim these engines run better an go faster as they get older, until they suddenly give up. So, perhaps you have the most enjoyable part of rotary ownership ahead of you.

Q: I have a '91 Mazda 626 with a 5 speed tranny. I want to change the oil. I think I have 80 W gear oil in it. I am not real sure though since I gather manufacturers sometimes put Dextron II in without a dye. My owners manual says I can use Dextron II or GL 5 gear oil.
Is there a problem changing over to a synthetic Dextron II from gear oil? Does all the old gear oil come out from the drain plug or do you have to do a few changes to get all the gear oil out?
Mark Miskiewicz

A: My application book does say that either ATF or a 75 W - 90 GL-4 or GL-5 fluid is used in that transmission. It also says to "check lubricant specifications label under the hood". This would seem to indicate there may have been 2 different transmissions used in that vehicle, one using ATF and one using gear lube. See if you can find the label under the hood and then try and determine what is in the tranny. If they are the same, stay with it. If not, cross your fingers and go with it.
I would tend to stay with what is in the transmission if you have had it for while and not had any problems.
Jim Tully

Q: I have a '91 Protege and recently it has taken spells on extended trips as the temperature gauge will not move up to the normal running temperature area. In fact during these times the needle does not move very much at all if any. During these times if I put on the heater, the air that comes out is either not hot at all or just barely warm. Any suggestions would be appreciated.
Michael Brown

A: It sounds like your thermostat may be bad (i.e. stuck in the "open" position). This would prevent heat from building up in the cooling system.
I would simply replace it with a new one rather than bothering to test it as it relatively inexpensive.
George Fisher

Q: I have an '88 RX-7 (non turbo) that once in a while gets flooded, especially if I start it up and then turn it off the engine without giving it time to warm up. When I do that next time I try to start it, it is flooded. It recently did it again even though I had not started the motor before. Any suggestions on what I can do to fix this problem.
Wayne S.

A: Fuel injected RX-7s seem to flood if you push on the throttle when starting.. But you seem to have leaking injectors. A fuel pressure test per shop manual will settle this. There is a temporary fix for this in the Mazdatrix catalog that involves a restricted bleed to fuel return line. If this is the problem you must replace the injector soon.
R. Duncan

Q: My daughter has a 1991 RX-7 with about 80,000 miles. Once or twice a year it gets flooded and is tough to get stared. It got flooded this weekend and she had to have it towed in to the dealer. They told her that the way to prevent it from happening is to never turn it off with a cold engine. This time she just moved it in the driveway. But, they didn't have any suggestions on how to get it started when it happens. Any suggestions? Once when it happened in our driveway some men came over and ran the starter for a long time (they even had to use a charger) and squirted in a lot of ether. I wonder if you could get it started by just towing it.
James Pramann

A: This has been famous on the rotary RX-7s for years. You can only let it sit, at least that's what mechanics have told me. I have had all generations and now own the 1994 car and was told by my mechanic that the latest version is the worst. He said to never start a cold engine, move the car, like out of the garage and shut off the engine, let it run for 5 minutes that is if you move the car. Just one of those glitches he said. My 1980 model did it to me in 1982 when I had moved it out to the street and realized I had forgotten something in the house. Didn't start until about 2 hours later. Never had a problem before with anything on a RX-7. Weird but a fact about the car
Keith

Q: I was considering purchasing a RX-7. I was informed that there were several different packages available. R1, R2, Touring, Popular are the packages. Do you know what the difference in the packages is?
Trey Francis

A: R1 and R2 are your basic racing looking models with back air damn etc. Popular is the basic without the racing look. The 1994's listed between $36,000 and $38,000. The touring package is the top of line with Bose stereo, all electric windows, alarm system, sun/moon roof (glass ), leather, etc. This model listed for $40,800 in 1994.
Beautiful car! They all are quicker than lightning, must be careful how you drive.
Good luck!
Keith Franklin

Q: I am looking to buy some aftermarket wheels for my '90 626 Touring GT. I prefer to buy used ones as I don't spend a lot of cash on this car, and I'm not particular about the style of wheel as long as they are 15" or 16".
Any ideas?
Brad Cook

A: I would recommend to buying Goodyear SP-40s (or perhaps 80) and they come in right size. They are not expensive, but very good tires overall. Very good grip on wet and dry, unfortunately not so good on the snow.
I finally fixed a plowing problem with them on my '89 626.
Dima Scherben

Credit Cards - Arizona Pools - Loans - Guitar Books

Members Only
Services:

MC Privacy Policy | MC Website Terms of Use