Engine turns over but won't start?

It sounds like a main power relay is not working here are tow guides that will helps fix it.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

and

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down these guides and report back.

I have a 1998 Mazda 626 ES 2.5 Liter and recently the harmonic balancer went, so we got it rebuilt and we put everything back together. Now the car will not start!! It sounds like its going to start, but it never actually turns over and starts but you can hear it cranking. I've heard that it could be the Crankshaft position Sensor? Does anyone know???? Please help. We have also changed the spark plugs and all that because it was sitting for sometime before we actually got the harmonic balancer fixed.

ALot of time the front crank pulley breaks with age and milage...but they are NOT rebuildable...if it broke abd enough, a piece of the pulley may have hit the crank position sensor and damaged it OR the sensor may have been knocked out of alignment with the reluctor ring on the pulley OR did you put a pulley put on from the same year and engine size?

Cosmo

I have a Mazda 626 2.0tdi dated 1998, over 300.000Km Is an european model
When the engine run for a long time, for example 1-2 hours of highway drive,if I stop it an restart , even within only some seconds, it never start again. The first times it happen, I need to wait 5-10 minutes, now I have to pass a intere night to cool down , and then restart. The only way to start the engine when is hot, is a starter spray (wurth fast start) in the air input (removing air filter). A garage man says that is the tank pump that have a pressure to low. This can be, but I don't understand how can the engine run for hours at 130km/h without problems, and stopping it for a second cause the no start. Any idea ?
Thanks a lot
Alberto

[quote:7e7512839b="a2sistemi"]Engine Mechanical problem
1998 Mazda 626 4 cyl Two Wheel Drive Manual 324000 miles
----------------------------------------------------------------
I have a Mazda 626 2.0tdi dated 1998, over 300.000Km Is an european model
When the engine run for a long time, for example 1-2 hours of highway drive,if I stop it an restart , even within only some seconds, it never start again. The first times it happen, I need to wait 5-10 minutes, now I have to pass a intere night to cool down , and then restart. The only way to start the engine when is hot, is a starter spray (wurth fast start) in the air input (removing air filter). A garage man says that is the tank pump that have a pressure to low. This can be, but I don't understand how can the engine run for hours at 130km/h without problems, and stopping it for a second cause the no start. Any idea ?
Thanks a lot
Alberto[/quote:7e7512839b]

I would say the pump is bleeding down or out of time like a distributor in the older cars

[quote:0d815557b2="Buzzsaw"]
I would say the pump is bleeding down or out of time like a distributor in the older cars[/quote:0d815557b2]

You are speaking about the tank electrical pump (there I suspect) or the high pressure pump ?
Alberto

[quote:f2e0485a1e="a2sistemi"][quote:f2e0485a1e="Buzzsaw"]
I would say the pump is bleeding down or out of time like a distributor in the older cars[/quote:f2e0485a1e]

You are speaking about the tank electrical pump (there I suspect) or the high pressure pump ?
Alberto[/quote:f2e0485a1e]

diesels usually have pumps on the engine not in the tank, ran from the timming chain, in which they need to be timed like a distributor, i am not a masda guy but I though I would try to help

[quote:d09de3d879="Buzzsaw"]
diesels usually have pumps on the engine not in the tank, ran from the timming chain, in which they need to be timed like a distributor, i am not a masda guy but I though I would try to help[/quote:d09de3d879]

You are right ! My 626 use only a Denso V5 pump, totally controlled by electronic. I've tested relais and FSOV solenoid and are ok. The spill valve have a resistance value different from service manual, but I'm unable to estabilish if it is damaged.

My car sat for approx. 1 1/2 months and we've had 30 degree weather recently but it's now in the 40's. Car wouldn't start, changed the battery, but still it won't start. Someone said to add a bottle of heet to gasline, cause the gas line could have froze, so I did. Still car does not start, its like gas isn't making the connection. The oil is good, the antifreeze is good, the battery is good.... Help!

[quote:334892b71f="a2sistemi"][quote:334892b71f="Buzzsaw"]
diesels usually have pumps on the engine not in the tank, ran from the timming chain, in which they need to be timed like a distributor, i am not a masda guy but I though I would try to help[/quote:334892b71f]

You are right ! My 626 use only a Denso V5 pump, totally controlled by electronic. I've tested relais and FSOV solenoid and are ok. The spill valve have a resistance value different from service manual, but I'm unable to estabilish if it is damaged.[/quote:334892b71f]

with the miles you got out of it I would say the pump is weak, might want to look into a rebuilt one or go to the junk yard

Do below and comeback with some results:

Disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,cap and rotor /distributor pick-up coil, ignition control module, ECM,Ignitor camshaft and crankshaft sensors- Note: If it doesn't apply disregard it

I have a Mazda whit the same problem. I need to know if you have the solution for the problem??
Thanks

thanks I'll try...let you know if that works!

I need help, because here in my country no budy knows the problem, my car don´t runn when is warm. I verify everything all sensors but nothing is wrong, I don´t understand...
Thanks....

Hi,
From my experience with the 2.0TD engine (98-02), the problem is most likely that some rubber parts have perished which are part of the diesel pump. The diesel pressure is lost so the car doesn't start. A good diesel specialist should sort this out without major expense.
Peter

Hi,
But if we take off the temperature sensor the engine start, I don´t understand why.
Here in Portugal there are not a solution and I don´t know what doing next. The car only have 153800 KM.
Rui

I've ha this problem for about 2 3 months now and it's a problem starting the car like it doesn't crank all I hear is the key when I turn it. Now this problem happens after I started the car and drove about 20 30 or however much I drive then I go to start it and nothing sometimes I'll keep on switching key to see it will turn on and it does but sometimes it hasn't I changed starter altanater and battery..

Hi there I have the same problem and a workaround but not solution.
I believe that this is connected with the Denso diesel pump.
When I bought the car 1998 2 liter mazda 626 the engine was working on emergency mode. There was a brown wire to a sensor next to the denso pump was cut. I connected the wire and the car had issue to start the engine when is hot.
Then I made a manual switch that I can change when the brown wire is connected once the engine start.
It is not the best way, but since it works I prefer this than Denso repair that is very expensive.
If somebody is interested I can give more details.

check fuses in pic then check to see if power goes through trans switch if no power through fuses try bending prongs just a tad to see if they will make contact as it may be a fuse box problem or corrosion on fuses

What's most likely happening is that the heat of the engine compartment is vaporizing the fuel because the pump pressure is insufficient to keep it liquid.

The car has been running rough at times and at other times it decides to cut off at low speed during stopping or pulling off. The other day the car quit running and would crank but not run. After towing home and checking code, P0320 was set. It is now 3 days later and went to look into problem, car started and ran.

P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction

Thanks, I check the code and found the same description. I did check the crank sensor as well by unplugging and the car would not run or start. Reconnected and it started. Noticed notches or teeth that the sensor reads are all evenly spaced except for one, as if it were missing a tooth, but doesn't appear to be broken off.

That is odd. They should be evenly spaced.

Any other ideas?

car turns over but won't start. checked fuel pressure and spark also compresion but still nothing. sparyed starting fluid and still nothing any one know whats up? or had same problem. tried crank sensor not the problem. I found the problem the timing had jumped a few teeth on cam side do to the spring on the tensoner breaking. Yes the car had fuel, compretion and spark. but when its off on the cam side it can only turn over but will not try to start. thanks for the help anyway merlin. nothing was bent because the problem was on the cam side.

The car HAS to be missing one of these ingriedients! Not possible for an engine not to start with good compression good spark and good fuel! What were the compression readings and did you check all cyls, with all plugs removed? When you turn the key on, are you sure the pump runs for a few seconds? And lastly are the plug wires routed corectly?

If the chain jumed a tooth or two, you better not try to run it! You will damage internal engine parts...

Hi,

How would I know if I had a faulty ECU? Is it possible for it to malfunction in only part of what it controls or would nothing work? Is it an all or nothing situation?

My car lost power on the highway, I noticed it had overheated & turned itself off. I coasted to the shoulder. It has never been able to turn over ever since. It cranks & I can see all the pulleys turning, etc, but just won't fire up.

I have replaced the spark plugs, thermostat, fuel filter, fuel pump to no avail. The fuses & relays seem to all be in order as well. A code reader I rented said their were "No Codes". I do however, have power to radio, locks, lights, windows, radio & a/c, etc.

I'm wondering if it's the ECU. I can not hear the fuel pump prime when I turn the key. We verified that fuel is not reaching the filter. Can part of an ECU get fried & yet have other things it controls still work?

We're just scratching our heads here.

Check and test both the main relay and the fuel pump relay, and engine fuse 15amp and EGI INJ 30amp

In my fusebox, there are:

Circuit
TNS
Air Con
H/L
Horn
EGI Main

I have tried to check them by switching them around. I know that my horn works as well as my H/L. So, I took those relays & tried them in Main, etc. No difference & horn, etc still worked w/ suspected relays in their place. Is this an ok way to check? The model #'s of the relays matched so I figured it should be ok.

The fuses all appear to still be intact.

I also wonder if my relays are in the correct order. I once saw a picture of someone Else's & the green one was in a different position. This was before I touched mine for testing. It must have worked because the car ran fine for years in that order. Just a curiosity.

i cant get my car to stART.i man a stop at a red light and it shut off on me.I tryed to start it up and no luck.

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it

i was driving one day and my car just died on me and started smoking where the alternator is and when i tried to start it, it sounded like the belts were just spinning and my battery would die after trying to start it so many times. my engine light was on and so was my oil light. i checked why the engine light was on and it gave me a code for a bad thermostat and there was enough oil. could it be a bad alternator that isnt making my car start or could it be the fuel pump. please help me. thank you.

scan for codes and check fuel pressure also check for fusible links burnt by alternator.

there is no code for bad thermostat. what was the number???

remove the belt and see if it starts

Roy

98 Mazda 626V6 cranks but won't start.

Cranks but no start condition:do below to determine whether it's fuel or spark issue:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem,Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.