motomike33y

Another crank, no start issue

24 posts in this topic

Wife's 626 quit when she slammed on the brakes to avoid an inattentive person crossing the road from their mailbox.  Crank but no start.  she had it towed to a local shop, who indicated that the timing belt broke, and there was no compression.  I hauled it home, and ordered a timing belt after reading up on the forum.  took off the ps pump and valve cover, and discovered the timing belt was intact.  I then took out the plugs and checked the timing-I and E lined up when the far cylinder(#1) was at top dead center.  Looking for any suggestions before I reassemble or take things further apart. 

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I discovered the plug markings were backward, so I ws on #4, but #1 should also be at tdc.  Not sure where it lines up with the crank mark as I still have the bottom shield on

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With a crank no-start always begin with a spark test and fuel pressure test.  If they told you the timing belt was broken and it's not then that calls into question their claims of no compression too.  That means you should do a compression test and see if there is actually compression.  Did they give you a compression test result with compression numbers for each cylinder?  Sounds like they were just guessing and didn't actually do any kind of diagnostics.  If you paid for that diagnostic I would try to get my money back or request proof.  Let us know how the results go and we'll be able to lead you down the right diagnostic path.  spark test, fuel pressure test, compression test.

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no copies of anything, so I'm not sure they ran compression test-I doubted their info since the engine is non-interference, and didn't bother to do my own compression test-I'll have a chance to work on it more next week so I'll check compression and spark before I start to reassemble things.

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got compression tester and checked cylinders, 60-15-30-30.  from some of the other threads, this sounds like maybe it jumped time, but I'll have to dismantle things further to see the timing mark on the crank pulley.  I thought I and E were supposed to line up at TDC-which they did with a screwdriver down the plug hole in #1, but maybe there is something I'm missing?

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Had a couple other projects to finish(clutch in new beetle and rebuilt heads/water pump/timing belt in Subaru) so moved Mazda into pole barn and got crank pulley and guard off.  Timing appears to be lined up.  Have to check distributer and will probably replace tensioner spring, although it is new style and looks ok in place.  Any suggestions before I throw up my hands and start putting things back together?  Starter apparently died in the interim as I had to make a tool to take crank bolt out.

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Took off distributer cap and it appears to be lined up with #1 for firing.  Still want to loosen tensioner pulley and play with it to evaluate cam timing.  All indications are that some other calamity than jumping time caused the sudden no-start problem

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Those compression figures are so weird. I can't get past that. Does it stumble at all, or just no firing whatsoever?

If your compression test is showing crazy numbers, and you can verify that your marks all line up properly, then it's gotta be head related. I would re-do that test to make sure.

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So now the starter isn't working-I had to devise a tool to hold the crank pulley.  Distributer appears to be lined up right.  Timing appears spot on, tensioner spring looks like new.  I'm going to put things back together, and double check as I go.  Doesn't make sense that sudden stop would do away with compression (car was starting and running without problem) unless timing jumped-which it shows no sign of. May have to get new starter if doesn't heal as I reassemble it.  Welcome any ideas about root cause 

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Starter: Try to tap the solenoid (small part) with a drift bar and hammer, maybe it's just a stuck solenoid.

Fuel: Loosen the fuel rail test bolt (top / passenger side - think it's 17mm?) just a bit and turn key on (but do NOT crank) - should spit some fuel out around the bolt showing that fuel pump is working. (Make sure you tighten the bolt back down afterward, of course)

Spark: Pop the distributor cap off, unplug both connections at the distributor, and make sure the rotor turns when you turn the crank. Then check coil windings by following the instructions found here: https://manuals.co/workshop/mazda/626/mazda-626-1993-2001-workshop-manual-haynes/5528396/155#pf9b

Compression: If it doesn't fire at all, then it's not a compression issue.

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Got everything back together, and starter works now(probably since ground now connected at motor mount).  Fuel came out when banjo bolt loosened and key turned on.  Took plugs out and they all sparked when grounded.  Still have to do compression test again and see results.  Will update.

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After re-reading your thread, I don't think you did a spark test since the moment it stopped. Am I missing something?

From what you discovered with the engine ground, it's tempting to theorize that the sudden stop (original situation) exacerbated a poor ground, thus disabling spark. Maybe that was the issue all along, an intermittent / poor ground....? Maybe I'm being too hopeful here, but it might just be that!

 

 

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Plugs work.  Did compression test.  60-15-30-40.  Somewhat different than first time.  Seems to turn over slowly so I hooked up my charger on 25 amp jump to give some extra oomph.  I haven't checked out the battery, which may be older.  If it isn't that, I'm going to tow it to my trusty mechanic and see what they can find.

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Battery voltage is 12.8, so that doesn't appear to be the problem.  Have to see what the auto shop can figure out.

 

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Well, if those are your compression readings and they are in PSI, and you're doing it right (seven or eight turnovers, wide open throttle, per cylinder tested) I hate to say it but those are horrible readings & seem to indicate some sort of catastrophic failure. You should be getting upwards of 140+ PSI per cylinder. Mine reads 141, 128, 137, 145 & that's on a 240K mile engine.

Sorry about your situation. I really hope it's something fixable. Best of luck!

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I agree, but I can't figure out why a car that was starting and running well would suddenly lose compression because my wife slammed on the brakes.  ??

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I agree, that makes no sense. Something's missing from the picture.

Plus, compression doesn't suddenly fail. You should have had plenty of poor running symptoms before that point, if compression was really that bad.

I don't think there's anything more I could say unless I were able to actually see it myself...

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Mechanic knew less than I did-confirmed low compression, then wanted ok for another $150 to check timing belt timing.  When I told that I'd done that, and to assume timing was ok, next plan was to either get motor rebuilt for $4500 or to get used engine swapped for $2100.  Apparently nobody does ring jobs anymore.  I told them I couldn't justify that expense for a car that cost $1400 and has 190,000 miles.  I'll bring it home and tear into it-putting rings in will be labor intensive but not a big expenditure.  Hopefully I can discover something during the process to explain what happened

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What year is yours?

I'm seeing quite a few 626's down here in the Metro Detroit area. I'm in Clinton Township, myself.

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Gave up on project, diagnosed in October with multiple myeloma, now in treatment and doing well but have to adjust my priorities and projects.  Will have to sell it as is or scrap it.  Merry Christmas and happy holidays to all

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