Practically Classics Forum

Hi

Looking for any useful suggestions for my non-starting Mazda MX-3 V6 1.8 injection on a '95 plate.

Basically she died a few days ago with a kindly (and very good breakdown guy) being thorough enough to test and check before diagnosing no spark. Confirmed this myself and have replace distributor (coil is within the dizzy) and HT leads. Now have a spark but still won't start.

As far as I can tell timing is ok.

Engine just turns on the key but doesn't sound like it wants to catch. Can't find a code reader to suit so trying to check the obvious.

Any ideas? Or any suggestions for an OBD1 Mazda code reader stockist (nothing on Fleabay either).

Cheers

Are all the leads on the right plugs/outputs on the dizzy? Checked the state of the spark plugs? Did the new distributor have points, if so have they been gapped properly?

When you replaced the distributor, how did you ensure that the rotor was in the same position on the outgoing & incoming items?

MX3 doesn't have points, right?

What sort of engine is this? Rotary? DOHC?

I'd be thinking it might have flooded - try spinning it with the throttle flat out.

Fuel pump/relay?

If you took out the distributor, is the timing 180 deg. out? That can produce a baffling failure to start as the timing will appear correct when checked against the timing marks. Make sure the rotor arm is pointing to the plug lead of the cylinder that's on the compression stroke, you can check this by removing a plug and sticking your thumb over the hole while turning the engine over.

You are right Luxobarge, no points.

The dizzy is interference fit to end of cam shaft - one way only. Room for slight adjustment by turning dizzy body but ecu should compensate to some extent - but this isn't even trying to catch. So taking a punt not timing as I would expect it to at least try and fire.

The engine is a V6 24 valve - the attraction is a v6 for me (hooked from my first 2.3 cortina).

Cam turnson the key so belt intact.

Was coming to a fuel issue myself. The tank is low so might top it up with a gallon then try. Car had been running fine until breakdown which was sudden and fitted with a coil dying, hence replacing dizzy/coil unit as a whole.

Plugs ok, HT leads checked, re-checked, swapped between oldand new and checked all connections firmly made!

Cheers

OK, favourite for me would be HT leads on the wrong plugs, as mentioned above. Ar ethe plugs getting wet at all when you crank it for a while?

Failing that, it looks like a fuel problem, although it's pretty unusual to get two problems occur at the same time.

I'd be tempted to give it a sniff of Easy Start or even squirt some fuel down the throttle body and see if it fires. If it does, it is 100% a fuelling problem. Yes, I'd make sure it has plenty of fuel in the tank first.....

Check the fuel pump runs for a few seconds when you turn on the ignition and when cranking. You could disconnect the fuel filter and see if fuel comes out when the pump runs - at least that would eliminate everything from the filter backwards, take fire precautions though.

Let us know how that lot goes and we can take it from there.

Cheers!

Can you hear the fuel pump buzz briefly when you turn the ignition on? Long shot, but happened to me before, the emergency cut out switch had tripped, so was cutting power to the pump, it doesn't take much if someone has knocked it in passing.

Double check the timing and leads are off to the right plugs. Double check the fuses too, with most having a fuse for ECUs, pumps, etc etc it's possible one has blown too.

Ok, I admit a degree of stupidity based on assumption. Original rotor fitted one way only, new one fits several directions.

Played around with rotor position of rotor and nowhave running of sorts - fires on turn of key but won't keep alive. Cuts out after what feels like one cycle but doesn't sound like it's missing on any cylinder in that brief moment.

Means I'm getting fuel and spark but why not keep firing?

After cutting out will fire again on next turn of key but repeats above.

Cheers

And there's more .......

Now starting after disconnecting electristo throttle housing and airbox - starts, hunts around a bit then settles to a reasonable tick over.That is until I try to open throttle when it cuts out.
also cuts out as electricals (either) are reconnected.

One step forward, three backward......

It's a start…