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My 94 Mazda 626 LX V6 has been having a problem where it suddenly quits while driving, usually after it warms up (10-15 miles) but more recently can happen anytime. Generally the engine RPMs suddenly drop to 0 on the tachometer and the car may continue to run with no warning lights for a few seconds but eventually the engine dies completely and the car stops. Occasionally can re-start by shifting to neutral while car is in motion then restarting, but usually not; car starts and runs fine after stopping, turning off, then re-starting but getting harder to re-start without letting it sit for a bit. Acts like something is going wrong when it gets hot; acts up more during hot weather.

I suspect a bad fuel pump or fuel pump relay; distributor was replaced about 8 months ago but I have been told if that is bad it will just go out and not start again. My mechanic checked but could not find anything wrong several months ago; incidence of occurence was sporadic then, but has since gotten more frequent and I am not driving it since I commute to work. Check engine light comes on after the first couple minutes running but does not come on right away at start-up. Engine does not really run rough (as plugged fuel filter or bad sensor might make it do); generally it just suddenly dies; tach drops to zero (but may go up again then drop again; sometimes will "recover" and continue to run), and after a few more seconds alternator and oil pressure lights come on. Alternator light may also flicker as engine dies as well. Any ideas what to check, and could this be caused by a bad fuel pump relay?

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First thing I'd do is pull error codes for free at AutoZone. Especially since you have a CEL (Check Engine Light). Hopefully that'll point you in the right direction.

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Welcome to the board!

The tachometer suddenly dropping to 0rpm even while the wheels are still rolling and engine is still turning is a classic symptom of distributor failure. As is the fact that it usually happens when warm, and usually restarts when it cools down. This is a very common problem on 93-97 626's.

It might be your plug wires are old and have helped cause the distributor to fail. But our cars have a very sensitive distributor.

You can check the cel codes yourself with a paper clip. Follow the procedure here. It takes about 10 minutes first time: http://homepage.ntlworld.com/mx6-uk/malf/malfcode.htm

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Yep! Such a difference between the 93-97 and the 98-02. We don't have to worry about disty failure, Yipeee! But I used to own a 93, and i currently own a 94 MX6 as well as a 2000 626, so I keep an eye on that thing!

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Thanks for the comments, and the welcome. :) Actually my own early suspicion WAS the distributor...since it went out last December and left us stranded. When i started thinking about that possibility I stopped driving it the 20 miles to work every day because I didn't want to get stranded and can't afford the tow...Paid the mechanic dearly for the remanuf. distributor and an air intake tube? (and waited a good 2 weeks too) cause he was having trouble finding it, and have been wondering if I should actually go back and ask him about it (read: give him grief about it); it actually started acting up again only a few months later, when I took it in last. I had heard that the 626's have a lot of distributor probs but started wondering about the fuel pump relay when another auto-mechanically knowledgeable friend said when a distributor goes it goes.

So sounds like the distributor IS a distinct possibility after all. Snailman, how hard is it to change ( you make it sound pretty simple), and can you recommend a reasonably priced source? heh. I am not exactly car-savvy but certainly mechanically inclined...for a girl, hahaha. (ahem roritor, that's SHE. lol. haven't figured out how to edit the profile info yet) And know enough to handle bolts and screws, for sure...on the other hand it certainly could be the plug wires since this car has over 200K miles on it and doubt they've ever been replaced. But otherwise runs great. NickR, yeah, I am gonna try that; I will take a look at your link!! All for getting the codes myself and didn't know I could do that...worth a shot. Roritor, I had heard AutoZone will do that for free also so got that on the list too...definitely need to get that read. I am just having second thoughts about this mechanic; my regular guy disappeared from the place I've gone to for years (two blocks from my frame shop) and so far not too impressed with the guy a block from my house...but trying to give him the benefit of the doubt...just rather fix it myself if I can, especially if it's something relatively simple to change.

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You can check the cel codes yourself with a paper clip. Follow the procedure here. It takes about 10 minutes first time: http://homepage.ntlw...lf/malfcode.htm

hmmm, NickR...I am gonna have to study that link for a bit to be sure I don't do any damage to my computer! The Autozone option sounds a little more user-friendly, lol...but I seem to recall hearing something negative about their code-reading service?? Like not thorough or something like that?

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Mechanics are like doctors. You know pretty damned quick if it's the right one and if not, the longer you stay with them, the more time and money you waste.

If you don't feel right about your mechanic, move on. A good mechanic is key and a bad mechanic can bring on more grief than almost anything.

But if you're still feeling this one out, then feel it out.

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That I am, still feeling him out. We have only had him fix this one major issue on this car in the two years we have had it so thinking I should give him another chance on this one especially if it has anything to do with the first distributor job. I like the guy and don't feel he's trying to con me or anything (it's a small town...his son plays HS football with my son, y'know?) so kind of have to see what happens next on this. Hate it when the guy you like and trust moves on and you don't know where he went...

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New distributor doesn't mean anything....I'm on my 4th or 5th one in the MX-6; lifetime warranty FTW. Hell, I've been contemplating keeping a spare in the trunk...two bolts and 3 screws, 2 minute roadside repair...

Last one lasted about 2 years, so far around 6 months on the new one....

Man you must have a serious case of bad distributors, there's got to be something causing your distributors to fail repeatedly. I have not had mines failed yet or from any repair order receipts left by my previous owner.

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KSsue: Yep, I'm pretty sure you need to replace the disty. But I would replace the wires at the same time, because *maybe* bad wires helped cause the dity problem.

I bought a new disty (with cap rotor and everything) at my regular parts store for about $150. Wires (get NGK blue ones, they are worth it) will be a bit over $100.

To replace the disty: look carefully at the two bolts on the oval holes. Remember where the bolts are in relation to the oval holes, and try to put it back in roughly the same place. (That's so your base timing stays the same, but don't worry too much about this because it auto-adjusts the timing.)

Unclip the two electrical connectors and plug wires.

Unscrew the two bolts, top and bottom.

Pull disty straight out. Have a look at the notch on the end of the shaft. You need to twist the shaft of the new disty so that notch is in the same place so it slots in.

Smear a little oil on the rubber O-ring, then slide the new disty in, with that notch in the same place, so it goes all the way home. This may take a couple of attempts, twisting the disty, to get it right.

Bolt it back up, same as before.

When you put the plug wires back on, remember to look at the little numbers printed on the disty cap. THEY MAY BE DIFFERENT FROM THE OLD DISTY CAP. Connect the plug wires using those numbers and these cylinder numbers:

Passenger compartment

1,3,5

,2,4,6

Radiator

Don't worry about busting anything when you use the paper clip to read the codes. The only thing you can bust is a 25 cent fuse, if you are very clumsy or unlucky. Hasn't happened to me yet.

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Thanks NickR! You've provided a goldmine of info for a try-to-diy-er like me; I know my limitations where cars are concerned in general but this didn't sound all that difficult. Your reply is the sort of thing I had hoped to hear, here. :) First I am gonna make sure there was no warranty on the one last installed (assuming not but gotta make sure...) and talk to that mechanic, see what he says. He couldn't get it to reproduce the symptoms last time I took it to him and I think it is happening frequently enough now that he should be able to get it to happen if he drives it long enough. But given the approx. parts cost, that's a pretty substantial labor savings if it's something I can tackle myself... and yeah, I did read that link on pulling the CEL codes a little more closely and saw that a blown fuse was the worst that could happen, and that, if you aren't paying attention... If it meant frying the computer or something I wouldn't touch it lol.

One last question. Is it possible the WIRES are the problem and not the distributor??? Or would a bad wire only make the disty go bad as you have been alluding to? Wonder if it would make more sense to replace the wires first and see what that does...cost IS somewhat of an issue but just want to get this baby running dependably again; my son wants his 'Stang back. haha.

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Bad wires don't suddenly all stop working completely, and then all start working fine again after waiting a few minutes. Bad distributors do. At least on these cars, because we have seen it happen so many times, but your mechanic was right when he says distributors normally just die completely, but your mechanic didn't know our cars.

Click on this link (our "bible") and read what loads of us have experienced time and time again: http://www.probe-mx6.com/problem.html#dist

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New distributor doesn't mean anything....I'm on my 4th or 5th one in the MX-6; lifetime warranty FTW. Hell, I've been contemplating keeping a spare in the trunk...two bolts and 3 screws, 2 minute roadside repair...

Last one lasted about 2 years, so far around 6 months on the new one....

Man you must have a serious case of bad distributors, there's got to be something causing your distributors to fail repeatedly. I have not had mines failed yet or from any repair order receipts left by my previous owner.

Nothing wrong with the car, they are just failure prone. I have newer plug wires, too. This isn't the first KL car I've had with distributor problems, either. My '94 626, when I had it, also needed a new disty twice. I HEI-modded it the 2nd time, and didn't have any problems after that (on that car). You have a '96...the '93-'94 models are the ones with the most problems (my '96 MX-6 is a '94 hybrid).

You can buy a brand new distributor, pre-assembled and complete with new cap and rotor, for about $200. Look for "Distributor King" on eBay....lifetime warranty, and they honored it, twice! (even express shipped it)

The new disty's are made by RPT (Richporter Technologies).

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Thanks Snailman, good to have a direct source and will squirrel that info away since I still think this is what is going on with it. Talked to the mechanic in question today (who replaced this distributor last Dec) and HE doesn't think that's the problem from what I told him it is doing..."too new" he says (among other things). He suspects a fuel feed problem, as was my secondary suspicion. But he hasn't driven it yet or had it fail on him so gonna have to leave it with him and have him drive around til it does so he can see for himself what it is doing. So have to give him a chance to actually check it out and see if that holds up. I'm not a mechanic but I do appreciate the feedback I am getting here; like you say Nick, he doesn't know your cars and may not be aware of that disty failure tendency in the '94 626. I am not one to tell the mechanic how to do his job but it certainly helps to be bolstered with this info in deciding what to do eventually...since it's not a cheap part it prolly makes sense to eliminate the other possibilities first. Just not convinced its a fuel feed problem; from what I have read of failing fuel pump symptoms, it really doesn't jive with what it seems to be doing. I will keep you all posted...and Nick, will take a look at that link and likely groan inwardly. :D

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Ok, got the car back from the mechanic's; he replaced the PCV valve and replaced/warrantied out the 8-month-old distributor so looks like he did reach the same conclusion after all (but apparently did not drive it much at all to get there...I assume you can check the disty currents directly at the engine somehow). So far so good; hasn't died on me in a few extended trips to town, although the weather has been cooler so will see what happens when it warms up again later this week. On the other hand, the check engine light is still coming on after a few minutes of driving, and now the cruise control doesn't work either when it was fine before. Could something have been inadvertenly been disconnected in the course of replacing disty and PCV valve? I will probably go back to him about that but wondering if any of you could enlighten me before I do. The cc switches seem to work fine; main switch comes on when pressed and the steering wheel controls illuminate the cruise light in the instrument cluster but but it is not connecting with the accelerator or whatever it connects to to hold the speed. SIGH. I was just so happy to have my car back...not that driving my son's 98 Mustang was such a drag but still... Should I maybe start a new thread on the cruise control??

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The cruise control device should look like a round vacuum booster thing where it's located on the far driver side of the engine bay, next to the brake reservoir. Check and see if the electrical connector to it is plugged in as well as the small long vacuum tube that goes from the top of it and then to a intake manifold port.

What does the Check engine light tell you?

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Thanks, I actually found an awesome photo of the 94 626 LX cruise control actuator posted by snailman 6 years ago on a post with a similar complaint, which zeroed in on the location of the actuator and highlighted what to look for; the vacuum hose was indeed disconnected. It was stuck into the top of the engine manifold; presumably they had a reason to disconnect and move it out of the way then forgot to reconnect. Reconnected to port on the actuator and problem was solved. THANKS. Love it when it's that easy, lol.

I have not yet checked the codes for the check engine light as outlined above and will see if it comes on again next time I drive it to work in the morning, a short 17 mile commute, since I only drove a few blocks today to confirm the cruise control was functional, and it usually takes a few miles/minutes for it to come on. All I know about the CEL at this point is from the manual, which states it indicates a problem with engine electrical, so need to run the codes to see if it indicates something specific. Wondering if the disconnected vacuum hose on the cruise control actuator might have triggered that so will see what it does next extended drive.

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  • 3 weeks later...

Ok, I'm back. To follow up one of the original symptoms, the CEL on, after the distributor was replaced: CEL continues to come on after a few miles of driving, every time I drive, and stays on until you turn it off; if you start it up right after turning it off it does not come on again until you have driven the obligatory few miles. Finally got around to pulling the codes from the ECU and came up with 02, 03, 15, 23, 24,and 46. whew. 02 and 03 are crankshaft and camshaft position sensor codes; 15, 23, and 24 are O2 sensor codes, and 46 is VRIS #2 solenoid code. After reading up a bit on these and looking at yet another excellent Snailman post on CEL code pulling and checking, I thought ok, it's running well, mileage seems fair, so I think it might just be remembering codes from past problems that have likely been fixed, possibly before we owned the car. Logical thing to do would be to clear the ECU then re-check it, both before and after driving it. So I pulled the console cover up and unplugged the ECU like it said (thanks Snailman), then ran the engine at idle for 3 min after reassembling everything, then decided to go ahead and run the diagnostic again to see if it was completely clear at that point or not. Did not drive it yet to see if the CEL comes on; it didn't while it was running in idle for 3 minutes so that's good But usually comes on when driving so will look at it tomorrow. The VRIS code is indicated on the chart as not memorized and I am a little confused about what that means, since it does come up when I run the diagnostics...so it must be remembering it??? ANYHOO, the code 46 VRIS # 2 solenoid was the ONLY thing that came up this time, after clearing the ECU and idling for 3 min; I will see if the CEL comes on during tomorrow morning's commute. In the meantime wanted to follow up here, and now that the distributor issue is cleared up thinking maybe I should start a new thread about the CEL and VRIS #2 solenoid.... From what I have read it doesn't sound like it's critical to the engine function, just affects power and torque at lower RPMs, but anyone have reasons to get this fixed? Does it affect fuel economy? Still a little leery that something else might have made those distys go bad...

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CEL is still coming on, chalking it up to the VRIS # 2 solenoid. Clueless as to why CEL doesn't come on until after driving for about 5 -8 min when to my understanding the solenoid malfunction code should check and actuate seconds after startup. Guess I need to start a new thread...thanks all for the helpful input.

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