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1998 Mazda MPV – Problems starting when engine warmed up

Been having this problem since this past Easter when our mechanic installed new valve cover gaskets.

When the van is hot (normal operating temperature) and you turn it off just for a minute, like to get gas, and try and restart it acts like it’s not getting enough gas. It will cough and sputter and balk. It will finally start though and after 30 second all will calm down and it will run fine.

One big problem is, is that is intermittent – meaning it won’t mess up for the mechanic and putting it on the computer shows nothing wrong.

One mechanic said it was a cracked distributor. Replaced that for $400. and same problem. I’ve also cleaned the Mas Air Flow sensor and changed the fuel filter.

Any help would be great… Thanks in Advance

James S

Usually when a vehicle becomes heat sensitive like this it turns out to be ignition system related. In your case your engine has a coil pack, and that’s the first place I’d look. The reason the computer shows nothing is that it’ll allow erratic ignition signals until the engine is started. If it did not, it the CEL light would glow after every turn on.

Just as an FYI, when you initially turn the engine off, the underhood temperature rises. The areas around the cylinders are a lot hotter than the rest of the engine, and when you shut it down the coolant stops flowing, the fan stopa spinning, and that heat begins to dissipate out through the sides & top of the engine as radiant heat. That’s why it’s only failing when you turn the engine off.

WOW – Thank you!! and it looks like a fairly inexpensive fix too… We will make an appointment to have that done… I will re post with the results… You are providing a great service!!

Thanks Again
JS

Hi TSM

As it turns out it was the Fuel Pressure Regulator

Thanks for the feedback. It’s good to hear the problem has been resolved.

The final solution only emphasizes that while we can render educated guesses over the internet, it’s pretty much impossible to do real diagnosis. For that one needs to actual vehicle.

sincere best.