UPDATE: Looks like the issue went away. It's been raining on and off for the last couple of weeks and so far it starts right up. Maybe it was just a coincidence he was having issues only after a rainy day.

 

Maybe, but either way, great news. It's always a good day when you get to keep a few bucks in your pocket.

 

See last post in this thread was 8 months ago but hoping nelaco or Sparky will see this as could do with their help. My '92 929 started behaving pretty much exactly as nelaco described his problem. In my case, not exactly rain, but having been parked outside (my other half's nicer car gets the garage) and nopt driven for the weekend - fair amount of condensation on outside of windows / generally damp, cool conditions. Would not start - turned over vigorously as battery less than 18 mo old, but would not fire. Showing 1/3 tank gas, thought maybe gauge had stopped working, so went and got 2 gallons. Whole exercise probably took 1-1.5 hours. Then although had to crank for a while, did finally start.

Then a week later - happened again. Was pretty sure not the gas gauge, but topped up the tank and tried starting - no luck this time. Had towed to shop - mechanic said when he tried it - started right up. Kept it a couple of days - checked fuel pump, charged the battery, ... but couldn't find anything wrong.

Yesterday (Mon) after again having been parked outside and not used over the weekend, wouldn't start. This time knew gas tank 90%+ full, so didn't top up, took Lyft to work and tried starting it again when I got home around 6pm. Still wouldn't start and again no joy this morning.

Mainly because of my competence/skills level :-), I have initially opted for Sparky's suggestions and have ordered new distributor cap/rotor kit and new plug wires which I will install when i receive them this Thursday. However, I think I might end up where nelaco did as I too at times have thought there might be a gas leak - not as much because of smell (although some) but because gas consumption has been very poor. Hoping nelaco can point me to where I can find all/part of 929 service manual so I can figure out how to replace fuel damper and associated intake manifold gasket.

 

I donated the car and looks like I deleted the manual. I think I used the engine section so I can see the torques and sequence. Other than that the manual is not really needed.
This repair did fix the sporadic no start issue. It is very straight forward, but like I said before, the one vacuum hose that connects to the back of the plenum is really hard to re-connect unless you replace it with a longer hose.

FYI, after I replaced the fuel damper, a few weeks later I started having a coolant leak. Ended up being a small hose UNDER the intake manifold so I had to remove everything again plus the intake manifold, get new gaskets, replace the old hose, and put it all back together. Fuel rail had to come off too for this one. You may want to do this if you are planning to keep the car much longer. This was the main reason I gave up on my 929. It was a fantastic car but being 24 years old, parts were starting to fail too often and the car wasn't worth much.
Good luck with yours.

 

Thank you for taking the time to reply. Well, the car started last night, this morning and again later today (early evening) when I left work. Each time virtually straightaway, just like it usually does. So I continue to be puzzled as to what might be going on. Have ordered most of the sparky suggested ignition system replacements (cap, rotor, plug wires) and will install them when they arrive tomorrow. At that time will also check coil. You wouldn't happen to know where I could find what the resistance specs for the coil should be?

Unless I discover I do have same fuel damper leak issue as you had, I think I'm going to give replacing it a miss. You're right that the car is increasing having problems. Being originally a "northern" car (michigan) hasn't helped. My mechanic has said that he is worried to touch fuel lines and other stuff as so much rust.

Will post an update in case it might help someone else.

Thanks again

 

I found these instructions including the resistance.


1992 mazda 929: drove..it wont start..power going..coil but nothing


Check primary resistance across coil terminals as indicated on image. 1. 0.77 - 0.95 ohms 2. 900 - 1,100 ohms
Check secondary resistance as indicated on image. 9K - 17K ohms
Check insulation resistance between primary positive terminal and coil case. It should be 10M ohms or higher.
Replace coil if it does not test as specified.

 

Thanks nelaco - looks precisely the info I need. Tomorrow will be the big day I hope when I am able to at least narrow down probable cause of the problem