Electircal/Fuel

ZACHMB12

MEMBER
1995 FORD THUNDERBIRD
V8
2WD
AUTOMATIC
175,000 MILES

I just got done putting a new heater core in my 1995 ford thunderbird 4.6L and a new fuel filter, I have everything back together and my car will try and turn over but will not start, it doesnt sound like the fuel pump is running but I went back through the dash and everything is plugged in where it is supposed to be, including the ccrm even tho I didnt touch it. Could it be I am just missing something or did my fuel pump decide to go out after I just got done with this mess? The car ran good before this, has new fuel injectors, Anything you guys can come up with would be greatly appreciated thanks

1 Reply

WRENCHTECH

MECHANIC
20,761 POSTS

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.