Car won't started after HC fix

[Gibbers18]

Repalced Heater Core now 1997 expo wont start!!

Hey Everyone:

Just finished putting in a new heater core and blend door, buttoned up the dash, and tried to start the car. All the lights come on, the engine cranks strong, but will not start!! The only thing I am not noticeably hearing is the fuel pump turning on. I checked the fuel pump relay and it works fine, the inertial cutoff switch is working correctly. Can anyone provide any guidance on this? I have the tech manuals and have been going thorugh line by line to try and figure it out, but so far nothing.

can provide any details as needed, but am just baffled at this point...

Thanks!!!

 

[stamp11127]

Keep it simple - check fuses for the fuel pump. There are two fuses, one for the primary side and the other for the secondary side. You stated the relay "works" which indicates the primary side fuse is good. On my 99 the secondary fuse is #10 and rated at 20 amp.

 

[Gibbers18]

Thanks, I will check tomorrow morning. Believe all the fuses were checked this morning and were good, but will confirm.

 

[Gibbers18]

Update 1/12/13:

So all fuses are working, I am getting voltage to the fuel pump, and getting 45-50 psi on the fuel rail. The car will start if I spray in carb cleaner while turning it over but won't stay running.

1) At this point the only two things I can think of are a) the injectors are not working or 2) there is a sensor that went off keeping the car from running with the injectors.

I did run an OBD tool, did not see any type of Codes or issues there.

So frustrated.....

 

[hwy73]

My 99 4.6 developed a crank/no-start (sitting in the driveway, luckily - in two feet of snow, unluckily). Developed normal fuel pressure at rail at initial key-on. Crankshaft sensor was bad, computer would not keep the fuel pump running because it couldn't see any revolutions from engine.

 

[Gibbers18]

I will take a look at that, but I am baffled to why removing the dash and reinstalling it would mess up the crankshaft sensor.....baffling

 

[hwy73]

It would be a sick coincidence

 

[Gibbers18]

Hi Everyone:

So I posted a link last week regarding my car not starting after fixing the heater core and am still not having any luck. I wanted to update the forum on my diagnostics to try and get some help getting this hammered out, really am tired of walking!

After replacing the HC and reassembling, the car would turn over just fine but would not start. I sprayed some carb cleaner in the intake and it would fire for a few moments then die again, so figured it is a fuel issue.I checked all my fuses and relays, everything was ok there.

Now here is where I think the trouble is. The ford tech told me to check the voltage at the inertia switch on the wire coming from the relay and fuse, and the wire going back to the fuel pump. With the switch disconnected, and the car on, I only read 6.8 volts. When I plug it back in, and then turn the car from off to on, I only see 6.8 volts for a SPLIT second and then it goes to 0,a nd I never see any volts on the wire going to the fuel pump. I don't see 12 volts for a couple seconds like I thought I should.

Anyone have any thoughts???

Thank you.

 

[stamp11127]

Your on the right track...
1) Check battery voltage and terminals for tight connection (don't laugh)
2) Check voltage to the secondary side of the fuel pump relay #30 on relay)
3) Check voltage to the primary side of fuel pump relay - #86 on relay
3) After the relay the circuit branches to the pcm and to the inertia switch, check voltage to the inertia switch.

All voltage checks should read at least 12v. Battery voltage should be checked on the posts instead of terminals.

Let us know....

 

[Gibbers18]

Stamp:

Thank you for the response! Here is what I have for your recommendations:

1) The terminals on the battery (which is brand new as of yesterday) are very tight.

2) I am getting about 12.17 volts on both sides of the #30 fuse.

3) In regards to this, how do I check the voltages with the relay installed?

4) This is where it gets strange... If I disconnect the connector to the inertia switch, I get 6.8 volts to the DG/Y wire and 12V to the GY/O wire with the car in the ON position. If I pluug it in, and then record voltage, I only get 6.8 volts on the DG/Y when in the ON position for a SPLIT second, then it drops to 0.