Itermittent fuel pump prime

ford
taurus
#1

2001 taurus 3.o 24 valve. When I drive the car and reach operation temp shut it off go into a store and come out the car sometimes will not start and run. It will stumble and quit, like vapor lock, but I have found it is because the fuel pump does not operate. If I wait 5 to 10 minutes the pump will prime and it will start and run fine. If it starts it runs fine and never quits. The warmer the weather the more it does this. Also when the car is not going to start the starter sometimes zings on the flywheel and does not engagel fully and after couple of attemts. it then engages and will not start correctly. It has never done the starter thing unless it is not going to start. I have replaced the fuel pump starter relay, the temp sensor, oil pressure sensor.

#2

The ignition module on many Ford products of that era were problematic. I remember changing them 3 times on my Ford Tempo.

#3

The no-start problem might be due to the crankshaft position sensor being effected by heat.

When you go to start the engine, and the ignition switch is in the run position, the computer energizes the fuel pump relay for a second or two to run the fuel pump to prime the fuel system.

Then when the ignition switch is moved to the start position to crank the engine over, the computer energizes the fuel pump relay so the fuel pump runs constantly.

If the crankshaft position sensor isn’t providing a signal to the computer because it’s hot, the computer see’s no reason to energize the fuel pump relay while cranking the engine over, and the fuel pump doesn’t run and the engine doesn’t start.

Then if you let the engine cool down, the crank sensor works again, the computer gets a crank signal, so the fuel pump runs, and the engine starts.

Tester

#4

Ask your shop to check for a healthy visible spark at a spark plug when this is happening. No spark, you know it is an ignition system problem (e.g. crank position sensor, ignition module, etc). If you have spark ok, it is most likely a fuel system problem (e.g. faulty fuel pump).

#5

I’m not quite sure what you’re getting at, no offense intended . . .

The Tempo ceased production long before op’s 2001 Ford Toreass was even built, and op’s car doesn’t even use the same ignition module. In fact, it doesn’t even use a separate ignition module at all, for that matter

#6

Ignition module, pickup coil, signal generator, crankshaft position sensor - all are heat-affected ignition parts that do what the points in distributors did in days of old. They tend to fail intermittently when hot, and if left in place, fail 100% eventually.

#7

We replaced our fuel pump and all was well. We had an occasional no start when warm, wait 1/2 hour and it started right up.