Mazda 929

1994 Mazda 929 Engine   

My car idles very rough when I'm at a stop light in drive. It will even completely cut off at times. The check engine light will go on and off and the rpm needle will bounce up and down irratically. I have to put it nutrual in order for it to idle steadily. This has started happening since I've had the engine replaced. I've had several machanics attempt to diagnose the problem and fix it, but none of them have been successful. I've a new timing belt put on it, The fuel injection system cleaned. fuel filter replaced , new spark plugs and wires and none of that has fixed my car. Now the transmission is slipping. Please tell me what's wrong with my car. I've put so much money into it becuase I really like this car.

Hi,

First the engine codes has to be checked by a qualified auto technician.It will indicates if a sensor it is at fault.

Second,
Please ask the auto technician to check your timing belt for proper alignment/timing marks.

Third,
Regarding transmission slipping,repair engine problem first and then look into transmission.If transmission its slipping the internal clutches are worn out and needs overhaulls.Very costyly.

You should know if engine performance its poor the transmission performance its poor ,too.
Good luck.
Peter
ps:Auto technician for over 30 years.

1993 Mazda 929 Drive Train / Driveline   

I have had a 1993 Mazda 929 for 12 years. It has 250K Kms on it but it is in good condition and very pleasant to drive.
A few months ago it developed a cycling vibration that appeared at about 55 kph then lessened/disappeared at 60 then came back about every 10 kph as speed increased. Over 80 - 85 it began getting more pronounced.
My mechanic determind that some of the universal joints (rear wheel drive, drive shaft with 3 U-joints) one in particular was stiff and potentially seizing. He had them replaced.
Drive shaft was re-installed but problem did not go away. It was removed & "re-balanced" but still no better. If anything it is worsening. The mechanic has not been able to pinpoint the problem but still feels it is drive shaft related & we are trying to find an economic replacement. My concern is is that it may not be the problem and how could a replacement be any better than the one with the new U-joints?
Given the age of the vehicle (17 years), replacing all the components of the drivetrain until the problem goes away could be very costly and perhaps greater than the value of the car.
What else could more likely be the problem and the best way to diagnose it?

Please further elaborate on 'cylcling vibration'?

What about the pinion bearing in the rear differential?

Has the driveshaft been damaged in any way? I'll check for driveshafts if you cannot find one.

Hi. Thank you for fast attention.

By cycling vibration I mean it comes and goes and comes and goes in waves as speed increases beginning at around 55 kph (65, then 75 then 85). If I maintain speed when it is vibrating it will continue the noise. If I slide the transmission into Neutral, the vibrating nois does not change, so in otherwords if I am coasting down a hill sufficient to maintain speed where noise is evident, if in Neutral, the noise will continue untill the speed slows down.
As for Pionion bearing, About 10 years ago I was aware of a slight whinning in the differential. I had Mazda dealer check it out. They did and advised me it was "normal" for Mazda rear drive vehicles. Some 175 K kilometers later I had not noticed any significant change in the differential noice. Somewhere along the way I did have the differential fluid replaced. Before this vibrating noise I was not aware of any change or woresening. External examination of the differential has not shown any significant problem & mechanic has not yet opened it.
As for driveshaft since U-joints were replace on driveshaft there has notbeen any damage that we are aware. It has ben balance & re-balanced but my mechanic is suspect of it. After I had sent in my querrie, he advised me he is getting a hold of another driveshaft that he can install & test. We MAY have progress but we have no idera yet. 2 other used shafts were found to not fit as apparently there were 2 different versions on the 1993 Mazda 929.
I hope this is of some help/clarification.
Ron

Okay,

Let me know how the replacement drive shaft works. I'm leaning with you though, no change with new u-joints and balancing but hopefully he is right. If there is no change again, may want to try adjusting the transmission alignment slightly to see if this makes a difference.

Thanks.

Ill let you know if I can find out how to do that on this system.
Ron

1992 Mazda 929 Engine Leaking  When warm 

the coolant is leaking at the rear of the engine when it gets warm( i cannot see exactly where bec. the view is blocked by the overhead intake).and also, i noticed the upper radiator hose is getting sucked flat and the cap is hard to remove bec. of the preasure.
i remove the thermostat housing to check on the thermostat and to my surprise, i don't see any thermostat in there. is that the cause of all this problem? is it possible the thermostat is located in other area rather than the upper rad. hose?
thanks

This problem has a few directions. First the thermostate missing is not the cause of your problems, yes it is a problem, replace the thermostate. Next, the hoses being sucked flat is also a problem, a sign of old age, replace all the hoses. Now for the real kicker. The water leaking from the back of the engine MIGHT be a hose that is leaking or it might be a freeze plug that has failed. It is apparent that this poor car has not had the antifreeze changed annually like recommended. The freeze protection does not go away with time, but the corrosion protection does. The corrosion preventive compound prevents the freeze plugs from rusting out from the inside, prevents the radiator from rotting out from the inside, prevents the heater core from rotting out from the inside... notice a trend here... additionally the annual flush prevents the radiator from filling with sludge and scale. The best thing you can do about the possible leak from the back is jack up the car far enough to get under the engine comfortably, USE JACKSTANDS!!!!, have the engine started and use a strong flashlite... find the source of the leak and fix it.. sounds hard.. it is not.. good luck. AL

Any reason why you released this ?? I thought I answered your question completely.. IF you have additional questions .. just ask them.. AL

1992 Mazda 929 Electrical / Lighting Systems   

My tail lights, dashboard illumination and fog lights don't work. I've changed the fuses and bulbs and clean the earth point but still no luck

Hello, I'll try to help you. Do you have a wiring diagram for these circuits?

I'll get one and look for clues to repair these lights.

Roger

I have a diagram. Do you have a 12 Volt DC test light or a digital multi-meter to make some tests?

Roger

1989 Mazda 929 Drive Train / Driveline Making Noise When turning Always

Hi...

My husband and I now have identical mazda 1989 929's;

1 sadly has pretty much died (fx head) after 208000 + miles... really good car.

Now, I recently found and bought an identical one as a replacement with 119000 miles and a good carfax... Everything is currently fine with it EXCEPT that it has this loud crunchy metal noise coming from the right front wheel area only when veering left or turning left... This is after we have had all the service and new tires and wheel bearing(x2-faulty part) and tie rod replaced. Three places have since looked at it and can't find anything wrong that would make that sound and only turning one way...

Before I resort to taking it to Mazda, I thought that I would look on the internet and have found this forum...

Our old mazda never made any noises like this one, so we and apparently everyone else have no clue; Can a mechanic here tell me if they have serviced a similar problem...????

Thank you

I hope that the shops checked the drive axles. I have come across interference with the brake backing plate when the car turns. I would still check the CV joints. They can make some funny noises when turning. Also, look at the strut mounts or struts. These mounts have bearings in them and strange things happen in turns---weight transfer, leaning. Crunching sure does sound like a bearing. Check those CV joints. Good luck
Tyler

Hi Tyler,

Thank you for your reply... Here is some additional info:
taking it to mazda found a boat load worth of faults:
a bad rack, leaking front struts, a bad rt wheel bearing(which I had replaced 2x--napa parts).

I finally resorted to taking it to another local mechanic and he could find nothing but the wheel bearing... so I let him replace it again with an o'reilly part. The noise has abated for the most part with his work... He thought that the others were just not pressed in correctly. I still hear the noise when turning at speeds sometimes, but it at least is not all the time now...

What is your opinion? and should we start looking around for a rack, use our old one from the other mazda... and perhaps replace the struts as well?
or should we just leave well enough alone...?

Thanks,

Shari

Use a rebuilt power rack. A used one copuld be worse than what's in the car. If the struts are definetly leaking, not just a little film of fluid on the shaft, they shpould be replaced.

Tyler

1988 Mazda 929 All Part Groups   

After sitting for two days over a weekend in the 20-40-degree range, the car started fine but fell off the high-speed idle immediately. Thereafter the car had less power than my 4-cyl Datsun, but idled and ran smooth. Passing gear was necessary to catch each next higher gear, and merging on ramps and climbing hills was dangerously slow. The engine was not outrunning the transmission, as in a bad tranny, it was just very weak. After I replaced the fuel filter, distributor cap and rotor, and checked the plugs, it would not start at all after sitting overnight again- third day after the initial problem, with about ten-twelve startups for errands and testing. Came to find out it's not injecting any fuel: if I supply fuel through a vacuum line, it fires and tries to start. Otherwise no firing at all, except about once per cylinder after sitting overnight: probably from injectors leaking the allowable one drop per minute till the rail pressure drops. The fuel pump is delivering gas to the surge damper within spec. Thoughts, besides the ECU (CPU) failing: can the inhibitor switch stop all injection, via the CPU? The Mazda shop manual mentions that it can influence mixture, but no details. Does either the security system (starter cut relay etc.) or the oil pressure cut off injection, directly or via the brain/CPU? Finally, is there a sensor value for fuel pressure (too much/little via bad pressure regulator) that will cause a non-inject response from the CPU? Or ANYthing you can offer. This is my 137000-mile daily driver, and my income is both fixed and low. Thank you very much. JohnHuffstickler "clintcoolbreeze@hotmail.com"

The first thing to check is to see if you are missing battery positive to the fuel injectors-- One end of test light to a known good ground and the other to the injector positive lead (Key On). Do you have the positive feed? As you may know, the computer pulses the ground.

Thanks- I'll have to check in the a.m. as I'm worn-out. The schematics & illos aren't too clear on where things physically are under the hood, but I should be able to reach an injector connection okay... No, I'll go do it now. Dying for some hard info. Thanks, and I'll post results, or whatever is right for this site. John

Hi- According to the line-drawing of the gang-plug (Driver's left at front of engine) and the schematic for wire color (Red-Yellow stripe splitting to multiple Black-Yellow stripe) I've checked an injector lead and found 12v with Ignition On, none when Off. So the brain isn't sending the ground cue for firing? Thanks, John H.

Exactly.

Is the security light behaving any differently, it'll usually tell you if you have problem with the security system.

Also check to make sure your grounds (computer) are okay as well as the battery terminals, cables, fuses, fusible links, etc.

Hi, and thanks for the good steer. Neither the Security system, Check Engine, nor Hold (secondary engine/transmission problem indicator) ever came on with engine running. All light up properly with key "on" but no engine start.

Sorry about the split message: I've checked many ground, voltage and resistance values on sensors and senders with a multimeter (Air box, throttle body, dynamic chamber, etc.) and all were okay. Does the computer have a local ground at its mounting bolts/cover plate? Thanks. JOhn H.

Sorry, one more: can the Oxygen sensor create a "no injection" situation? Thanks.

More background- About ten days before all this, car had a classic "won't crank" situation. After I tried shoving it hard into Park, cleaning Batt terminals, etc. my dad ran it through the gears and back to Park, and it started right up. Thanks.

Sorry about writing a book here: How do the injector connectors come off. Don't want to force anything-

In rare cases the oxygen sensor can shut down the computer (as can other sensors). This is always a shorted condtion, simply unplug the sensor to eliminate it from the ciruit. Also inspect the wiring for a short/rub through. Additionaly ohm the injectors to see if they are all in the same range.

The injectors should have clips- if you look closely- to release.

Disconnected O2 sensor- no good. I take it that the car would run, but maybe roughly, without the O2 sensor. Still trying to loosen injector wire to confirm voltage, but very hard to reach/manipulate unless I remove the plenum (dynamic chamber.) Is voltage @ injectors always 12v? On the ECU's ground-signal question, is there a primary ground at the computer mounts? Hard to tell from schematic. Also, when the Theft-Deterrent system declares a No-Start condition, does it disable injectors as well as starter? Thank you. John H.

Reason I asked earlier about oil pressure & injection: some older cars cut fuel if oil pressure dangerously low (cut fuel pump on my carbureted Toyota truck.) After Mazda's first day of bad running, oil pressure light flickered a couple of times, and I found it barely on the stick. Topped it up, but no help. Thank you, John H.

Got one injector connector loose- confirmed 12v @ injector. Thanks, John H.