HELP! 93 ford explorer wont start!

[sonnyandveronica]

My 93 ford explorer wont start. The engine turns but it wont start. I was told there is no spark. I replaced the module and the crank shaft sensor and it still wont start. I was told it could also be the computer but could it be anything else?

 

[andre 244]

is check engine ligth if it go on when u turn key ? may have bad fuse or ecm relay
do you hear the fuel pump working

 

[sonnyandveronica]

no check engine light i was told the pump is working

 

[andre 244]

whe to key is on you must have check engine ligth on the after about 3 second go off
if not youre ecm not geting any power

 

[sonnyandveronica]

what is the ecm

 

[andre 244]

engine contol module "computer" also call ecu engine control unit

 

[sonnyandveronica]

The light does not come on so does that mean i need to replace the computer or what would cause it to not get power

 

[andre 244]

here what you do turn key till dash lith are on check if check engine is on
if yes good sing
if not check fuse or you're bulb may be burnt out
if you can check if you have injector pulse by diconecting plug and put a 194 bulb it should flash when you try to start

 

[sonnyandveronica]

The fuse to the check engine light or to the computer. And where is the plug to check the injector pulse. (what is that for)

 

[Slatch]

First thing I would check in your situation is the PCM relay. Look at your owners manual, it is located in the power distribution box under the hood. Swap it with another relay of the same style and see if there is any change.

 

[sonnyandveronica]

in my owners manual under the power distribution box i cant find the PCM relay which one is it

 

[MrShorty]

Sometimes it is labeled EEC relay.

A wiring diagram (even the ones in Chiltons) will help you see how the PCM gets power. The EEC relay might be working because the fuel pump relay should require power from the EEC relay to run the fuel pump.

 

[sonnyandveronica]

So if it is not the eec relay what else might i want to check before going and buying a new computer.

 

[MrShorty]

The rest of the PCM power and ground circuits.

 

[sonnyandveronica]

Is there anything specific I should check or where and how should I check. And Thanks!!!

 

[MrShorty]

Power circuit: I'd probably start at the PCM and make sure the three power wires have 12 V with the key on. If yes, then the PCM power circuit is good. If not, then move back to the relay and make sure it is closing. With your wiring diagram, continue up the power circuit until you find 12 V. The problem will be between the point in the circuit where you have 12 V and the point where you don't have 12 V.

Ground circuit. Assuming you have power to the PCM, grounds are usually best checked with a DVOM. Measure the voltage drop across the three grounds (positive lead at the PCM, negative lead at B-. There should be very little voltage drop (several mV at most). An ohmmeter could also be used with the PCM connector disconnected. There should be essentially 0 ohms resistance between the connector and B-.