Mazda non start
Discussion
Needing help guys, Mrs Mac's Mazda car won't start!
Fuel & spark seem o.k., can't find any vac leaks. The engine will start if I spray some petrol into the inlet manifold first. Then it hunts on idle, is down on power when driving and the engine has a major flat spot (suspect possibly missing on a cylinder). The engine will not restart without spraying fuel into the manifold first!
Any idea's? Thanks in advance.
Fuel & spark seem o.k., can't find any vac leaks. The engine will start if I spray some petrol into the inlet manifold first. Then it hunts on idle, is down on power when driving and the engine has a major flat spot (suspect possibly missing on a cylinder). The engine will not restart without spraying fuel into the manifold first!
Any idea's? Thanks in advance.
Nick1point9 said:
when you say fuel ok, what do you mean?
If its able to start with you adding fuel, then its got a healthy spark, its got compression etc etc. You stop adding fuel it hunts.... sounds to me like its not fueling properly....
Nick 1.9, only checked for fuel flow after the fuel filter by switching on & off the ignition, flow seemed very good. So the engine is getting fuel, no doubt there.If its able to start with you adding fuel, then its got a healthy spark, its got compression etc etc. You stop adding fuel it hunts.... sounds to me like its not fueling properly....
To start the engine I need to spray in some fuel at the mainfold first, then it will start, but hunts at idle slightly.
Johnboy Mac said:
Nick 1.9, only checked for fuel flow after the fuel filter by switching on & off the ignition, flow seemed very good. So the engine is getting fuel, no doubt there.
To start the engine I need to spray in some fuel at the mainfold first, then it will start, but hunts at idle slightly.
What fuel pressure are you making at the fuel rail? Flow doesn't equal pressure, and flow alone isn't enough. You make also have a blockage preventing fuel getting to the rail, does the fuel pump sound normal?To start the engine I need to spray in some fuel at the mainfold first, then it will start, but hunts at idle slightly.
I'm not saying it's definitely a lack of fuel, just trying to establish why spraying fuel helps.
Nick1point9 said:
What fuel pressure are you making at the fuel rail? Flow doesn't equal pressure, and flow alone isn't enough. You make also have a blockage preventing fuel getting to the rail, does the fuel pump sound normal?
I'm not saying it's definitely a lack of fuel, just trying to establish why spraying fuel helps.
Nick, I've not pressure tester so I can't say. Yes, the pump sounds normal. I might be able to get my hands on a perfect f/rail & a set of injectors tomorrow. If so, I'll try them and slap on a new f/filter while I'm at it but I'm doubting those will resolve the problem. I'm not saying it's definitely a lack of fuel, just trying to establish why spraying fuel helps.
If you have anymore ideas I'd be grateful. Thanks for your input.
Johnboy Mac said:
Needing help guys, Mrs Mac's Mazda car won't start!
Fuel & spark seem o.k.
As others are suggesting...expand on this.Fuel & spark seem o.k.
So are the injectors actually spraying fuel ? Or at least, are the injectors getting a signal ? and 12v ?
As for sparks...so you have verified a good strong spark on all cylinders ?
stevieturbo said:
As others are suggesting...expand on this.
So are the injectors actually spraying fuel ? Or at least, are the injectors getting a signal ? and 12v ?
As for sparks...so you have verified a good strong spark on all cylinders ?
Yes, the injectors are as I can get it start,idle (hunting) & drive (flat spot, slight miss) once I've primed/sprayed the inlet manifold with fuel. A good spark to all plugs too. Strange eh? So are the injectors actually spraying fuel ? Or at least, are the injectors getting a signal ? and 12v ?
As for sparks...so you have verified a good strong spark on all cylinders ?
A dodgy battery can actually give some very weird symptoms in how an engine runs on a modern car, even if it does actually start the car.
At this point without some proper sensor scans or delving deeper it's hard to diagnose.
Plus we are working on Mazda alone. Nothing more.
What model/year/engine is it ?
if it's a rotary....things could change.
At this point without some proper sensor scans or delving deeper it's hard to diagnose.
Plus we are working on Mazda alone. Nothing more.
What model/year/engine is it ?
if it's a rotary....things could change.
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