My 93 miata has starting issues... sometimes it starts up fine and sometimes it will crank for ever but not start...

It always has fuel to the rail and spark when it cranks but won't start...
It has been doing this for a while.. I just rplaced the plugs and wires with no help..


Any help is appreciated...

 

They say that you need three things for an engine to run. Compression, fuel, and spark.

It's pretty obvious that you have compression, so that just leaves fuel and spark. If it's cranking but not starting, then you're missing one of the two.

Well, actually there's a fourth element. Not really a fourth maybe, but a third-and-a-half. Timing. If you've got spark, but you've got it in the wrong place, that's more-or-less the same as not having it at all.

We tend to be cynical and doubting people here. Give us a little background on how it is you came to be certain that you have both spark and fuel, and yet a non-starting engine?

 

i have fuel at the rail, i dont know if the injectors are getting the signal to spray all the time or what? but i know the fuel is getting from the pupm, through the fuel finlter, down the lines and to the fuel rail.

i pulled the lines off of the fuel rail and the fuel pump is shooting fuel out as it should, and when i pull a plug wire and put another plug in it and contact it to metal it shows spark. thats how i know i have fuel and spark...

once the car starts it runns prety damn good... im going to time it soon just to double check...

thanks

 

Re-check the timing belt alignment, and, run another ground to the engine block.

 

ok il will try that... ive noticed it onlly does it when the engine is cold and when it the air temp is below about 70

 

I had similar issues with my wife's Toyota. It wouldn't like to start when cold or damp.
Turned out to be the coil-packs.

 

a similar thing just happened to my '90. it was running and once i shut it off, it wouldn't start back up. i did notice that the sensor on the back of the head has since snapped off in the connector, which would explain the CEL perhaps, but not the no start. does anybody have any ideas on where to start?

 

The Idle Stabilizer Control Valve (ISCV). Some people won't agree but without it my car won't start.