Got it scanned today. All codes are clear. Still doesn't want to start. After prolonged cranking, it will start and run til it is shut off. It will stall if put in gear. It is getting fuel but mechanic says it is not getting any spark. There is no electrical problems in any other area. My mechanic is taking the computer to get it checked.
What could it be? Why No code?

 

Hows the fuel pressure regulator? It could be that the computer is not giving enough fuel upon initial start. But, also check the fuel system components.

 

I have seen a few sportages around your vintage that would not start on this forum. Would you check the compression of the cylinders? The ones that would not start had unusually low levels (120psi) and one of these cars had low compression AFTER the timing belt was replaced. There was a comment about these being I believe an early Mazda design and they needed higher compression to even start. I wonder if cranking the engine and some of the gas firing would heat the engine just high enough to increase the flash point of the gas with the low compression and allow the engine to start. (and sustain operation).
I also wonder if timing of the cams and valves in relation to the crank position may actually be WRONG just enough to cause these problems.
Anyone owning one of these running engines might want to check the timing marks BEFORE removing the old belt. Maybe the manual is wrong?
I wouldn't think a careful replacement of a timing belt on a once good running engine would cause any other damage to that engine. the compression readings might give us a clue.
Dave

 

May have found it

I think you may have something there about the heat causing a flash point.
But my mechanic tested the compression. There was NONE!!!
So he wants to replace the head gasket. He insists that my piston rings etc are OK. Shouldn't there be a code for compression? There is for about everything else!!

I really didn't want to go that deep into the engine until I could re-build the whole thing. But I am broke from all the error codes it was throwing. At least I am learning from it. I can take apart the top pretty quickly now and don't have to arrange the parts in order as they come off.

 

I am a bit confused (which isn't unusual). You say it runs but doesn't have compression? NONE was the word you used. You also said the mechanic told you there was no spark. Again it can't run no matter how long you crank it with out the spark. I would not tear it open until you find out yourself if these two conditions exist. If you have spark and compression then your problem is most likely fuel. Low fuel pressure or volume is the culprit.

 

I'd say buy a $35 comp guage and check it out your self, it's a fairly simple process. If nothing else, ask your mechanic for a readout of the compression numbers.

The minimum operating compression for these motors is 138psi according to mazda's data. The maximum is 199psi.

the lowest compression reading should be no less than 15psi of that of the highest.

If cyl #1,2,4 are 170psi and #3 is 120, that's bad news, but if the readings are within 15psi (such as; 166,172,162,166) that's an acceptable range.

 

I think my mechanic really doesnt want me to know everything because I ask too many questions. I will be watching him do this job(the head gasket). I dont gripe, I hand him tools, offer to get him food and drink, but ask ALOT of questions. He might be getting sick of me.

 

Your fuel injectors may be leaking down while shut down, the will dump raw gas into cylinders,causing a hard start , by inducing more air into the cylinders (opening the throttle all the way) will lean the mixture allowing your engine to start. A way to check , do you have black smoke after starting? A lot of people over look fuel injectors, they don;t last for ever.
I had a similar problem with one of my 2ooo's, found 1 bad one , so i replaced them all. Starts fine now.Also if the o rings are bad that would you a false compression reading.

Good Luck

 

Gosh I hope there isnt anything wrong with fuel injectors. I left my mechanic alone. He found where the head gasket was leaking between cylinders. So hes putting it back together. Will let you know what happens after we get it running.

 

IT STARTED!! YEA! After my mechanic installed a new "keyway" it fired right up. I keep thinking that we wasted time and money installing other new parts but the engine does have over 185,000 miles on it and those parts were toward the end of their life. It was giving us the codes that they were bad.