Won't turn over until it cools a bit

mazda
gasoline
mpv

#1

Thinking the fuel pump. Any ideas? thanks


#2

Or, it could be a “heat-soaked” starter.

While this phenomenon seems to plague mostly large-displacement GM V-8s of the '70s & '80s, I suppose that it could occur on an MPV, especially if any shielding/insulation between the exhaust manifold and the starter is missing.

Is it possible that there was originally some shielding/insulation that has fallen off of the exhaust manifold?


#3

I’m thinking not fuel pump, bad starter, or carbon in the cylinders. Care age and type of driving, ie just around town or many highway miles.


#4

When you say it “Won’t turn over”, do you mean the engine will not crank when you turn the key, or it will crank but not ‘catch’?


#5

It cranks but won’t catch, has about 100k. Previous owner did the 50k service. thanks


#6

Commute about 20 minutes on highway. Otherwise it’s just around town. thanks


#7

What can I do about carbon in the cylinders?


#8

I’ll check, is there a way to check the starter other than just replacing it?


#9

Commute on the highway should take care of any carbon buildup, quick fix is to get a spray bottle of water and hit the intake after the air filter, you would be surprised how much it can take. Based on your response starter motor, suspect 1, though before replacing it a check of cables and connections would be in order. I have read posts of shims etc. for the starter motor, but have not had a car that needed or suggested them. See post below, I misunderstood the question at hand


#10

In that case, you can rule out a heat-soaked starter.
You earlier said that the engine would not “turn over”, but now you tell us that it does turn over, as “cranking” = “turning over”.

When you take it to a mechanic, if you tell him that the engine will not turn over when it is hot, he will assume you mean that the starter motor does not turn when you twist the ignition key.

It seems that there is much confusion about the actual meaning of automotive terms with the general public, and this leads to many blind alleys and inconclusive diagnoses.


#11

Sorry I misunderstood your initial post, yes fuel pump is a definite possibility. A clogged pickup sock in the tank is another option, as is a fuel filter.


#12

Forget all about the starter since your car will “turn over” - it just won’t fire.

You can be having a problem with spark - heat soaked ignition components - electrical resistance increases with heat.

Or

With fuel. You might be getting too little fuel (e.g. from generally low fuel pressure, clogged fuel filter, weak pump with a bad check valve). Or you might be getting too much fuel - i.e. the engine is flooding when you turn it off from leaking fuel injectors or a leaking fuel pressure regulator.

To check for spark get a spare spark plug or a spark tester (auto parts store).

To check for lack of fuel, spray some starter fluid into the throttle body before cranking.

To check for too much fuel, floor the gas pedal as you turn the key and then ease up as it fires (if at all).


#13

Thanks for replying, if it is a clogged gas filter will it fit the symptoms where if it sits for 20 minutes it will start? It finally happened to me instead of my gf. Starter is working, engine will not turn over. I did spray starter fluid in the throat and it did start. I’ll get a fuel pressure gauge and check that. thanks


#14

hey, remember me? Here’s a twist; the car began acting normally. Started right up for about two weeks. This morning I turn the key and nothing. The lights, power windows, gauges all work normally. When I turn thte key to start, nothing. No click, no dimming of lights etc. I thought ignition switch, maybe anti theft system. We bought the car second hand and never thought it had one. Mechanic says the anti theft might stop the fuel pump from working or disable the ignition,but not both. PS I had it towed, started up just fine at the mechanic’s.


#15

new coolant temp sensor fixed my similar problem