hello thanks for having me i a newbie heres what i got a 91 explorer 4.0 that wont start at frist it started you drive for 20 or 30 min it would die now it just does not start i have replaced fuel pump, fuel filter, iac, crank sensor, tps, fuel pump relay, any ideas anyone any help would be appreciated thanks jramjr

 

First, you need to figure out what's missing. An engine needs 5 things to run; fuel, air, spark, compression, and timing. Most common failures of the 5 things are spark and fuel. To determine if you have spark, you can use screw driver with a well insulated handle and place the shaft into a spark plug wire making contact with the metal inside. Then while holding the shaft very near to a good gound, look for spark while having someone crank the engine. Note that if you get too far away from the ground, or the handle is not very well insulated, you will become the ground and a resulting electic jolt to your body will show that it has some spark. However, just because it's enough spark to hurt like all get out, doesn't mean that it's a good spark. After the shock has gotten your attention, and you've thrown the screwdriver about 100 miles away, you can still check for a good spark by taking a known good spark plug, connect the wire to the plug and lay the base on the plug on a good ground. Have someone crank the engine and observe the plug for a nice blue spark. If you're not adventurous, you can skip directly to the second method.

If you have a good spark, the next logical thing to check is fuel pressure. For that you will need a guage to connect to the schreader valve on the fuel rail.

Based on the results of the tests above, your next steps will be defined. Also, it is ALWAYS a good idea to pull any codes from the computer. There can be stored codes even if the check engine light never came on.

 

When you turn the key to the ON position, you should hear the fuel pump prime for a second or 2. If not, then your problem is probably fuel delivery related and you should then check for spark. If you're not getting fuel, also check the interia switch. Make sure it's not tripped, and that the connecting wire is on tight.

 

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thanks try that in the morning

 

If no spark, take your ignition module in to be tested. Please keep us posted on your progress, I have the exact same vehicle doing the same thing and I am running low on ideas, good luck.

 

ok guys got the explorer runing part fuel pump relay 10 at local ford dealer thanks for the help