Engine Cranks but wont start
 

Hi all, I have a 2002 F350 duly I drove home the other night, parked in the driveway and went in and had dinner. About an houre and a half later I opened the hood and repaaced the G P R wire for wire to terminal for terminal. went to start the truck and she cranks but will not start. I connected a O B D 2 scanner to the diognostic port and in says it can not connect so I don't have the benifit of any DTC'. any help or ideas would be greatly appreciated.
Thank You,
Mark
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Does your Wait To Start light come on?

Which wire did you replace?

Greg thank You for taking your time to reply, I replaced the glow plug relay and re conected the wires on the new relay as they were on the old relay Thankyou ,
Mark

OK. So I presume your wires look like the photo I posted....

Does the Wait To Start light come on?

What GPR did you replace it with?

If that was all you did and you replaced it with the right GPR, it should start...

The wiring on the GPR doesn't matter as long as you get the big wires on the big lugs and the little wires on the little lugs...

the glow plug lite does come on and i bought the relay on e bay there is a guy that sell a lifetime relay. In addition to that you can buy a manual switch so you only use the relay/glow plugs when it is cold out.

Mark

correctiom IS NOT cold out
Mark

switch on manuely when the temp is cold NOT having to use in warmer wether


Mark

So, did you wire in the manual switch? If so, remove it, check your fuses and replace if blown and then see if the truck starts.

Do you hear your fuel pump when you first turn the key on?
Is there any smoke out the tailpipe while cranking?

I checked every fuse with a multi meter. No sound that I can here of fule pump. No smoke from tail pipe. I do here a relay clicking when i turn the ignition switch to the on position. It is relay# 303 (Injection Drive Module Relay) i changed relay and it still clicks untill you turn the key to the off position
Thanks, Mark

No smoke while cranking means the injectors are not firing. Make sure you have 10.5 volts WHILE cranking.
The IDM will not fire the injectors with much less than 10.5 volts while cranking.

Edit: Here's some info

https://www.ford-trucks.com/forums/a...5&d=1215707540

Payson thankyou for replying, The batteries are up tp snuff and the engine cranks fast. However the I D M Relay clicks as if it wern't getting enough power to pull it in. I took a 2 gage jumper cable from the battery to the power lug of the fusebox just to make sure I had proper voltage to the fuse block. Thanks Mark

I know you checked all of the fuses but check #30 again I think.It is the one that says cigar lighter.It is tied to the fuel bowl heater and pcm.If it is blown because the fuel bowl heater shorted out it will not start.

Clicking relays is usually low voltage. The engine will turn over pretty fast even when the batteries are down. You must check voltage with a meter while cranking to be sure.

Like Robin said, no smoke means the injectors are not firing (or there isn't any fuel available). There was a thread a while back where someone had no voltage at the fuel pump. They found a defective wire at the glow plug relay, fixed it and their fuel pump started working. I still don't know how that had any play but according to the attached wiring diagram, the keyed power for the glow plug solenoid is on the same circuit as the fuel pump so that could be your issue. Depending on how you wired up your manual switch, you could have affected the fuel pump somehow. Again, I am not sure how that can happen but I just remember that thread and how the OP solved his issue.

Here is the diagram.

ok will go and check cranking voltage and fuses

Keep in mind that the fuel pump will only run for about 20 seconds if the engine doesn't start. You have to cycle the key again
to get it to run for another 20 seconds. Also if checking for power at the pump it must be done in that initial 20 seconds.

I have 12.2 colts at time owhen engine is cranking checked fuse and is ok. One other thingI checked was the fuel pump shut off switch and it did not need to be reset, However i took a test lite to the two wires that go to the switch and I find no voltage in either wire.

have u ver replaced the cps

yes one of the first things I did after replacing the GPR

I replaced Cam position sensor I did not replace the crank position sensor

I think one of the most productive things you can do at this point is confirm that you have fuel. Slip a length of hose over the discharge tube and drain the fuel bowl into a suitable container. Then have someone turn the key on while watching the hose and see if fuel is coming out.

Like previously mentioned....the PCM will shut down the fuel pump after about 20 seconds if the engine isn't started so you might have to cycle the key once or twice.

Confirm you have fuel and then we'll go from there.

drained the fuel bowltill it stopped comming out of tube, Left valve open and had my daughter turn key to the on position for 30 second did we did 3, 30second cycles and not one drop of fuel and did not here fuel pump either.

yes I have a Superchips tune in the pcm I tried to remove the tune but the tuner that plugs into the OBD2 port will not connect with the pcm and also the OBD2 scan tool will not connect with the PCM either. bad PCM ?

The Superchips is am handheld plug in tuner that once you install the tune Via the OBD2 Portyou un-plug. I pluged it in to retreve the tune out of the PCM but the hand held tuner will not connect with the PCM.

I thought so.
Go back to your original post. Your answer is there. Problem began when you replaced the GPR so I suspect something with the wiring.

I don't see that you answered the question about the manual glow plug switch. Did you install something like that? Perhaps the new relay is causing the issue. You can check this by swapping it with the AIH relay instead.

Can you take a photo and post it here?

I uninstalled the manual switch and put it back as stock.

Ok. I wish I could remember the other thread where someone had the exact same issue. No power at PCM and fuel pump was dead. They found a bad wire going to one of the relays, fixed it and everything started working again.

Did you look at the powertrain diagram I posted earlier? Those items are on the same keyed power feed so maybe we just need to find out if there is a broken wire somewhere.

Have you tested the relay with a meter to see if it's working?

I have 12 v-dc at the always live lug then I turn the egnition on and the other big terminal becomes energised

Does the other big terminal go dead after a couple of minutes with the key on?

the manual switch that i put in replaced the original 2 little wires that come from the wireing harnis I taped the ends of each wire and left them to the side and put te manual switch in. Now however I removed the manual switch and re connected the original wires that come from the wireing harnes

I just double checked the New Relay I installed. As I said earlier I returned It to stock and with out the manual relay switch and now the 12V-DC does not transfer to the 2ND big terminal like it is seposto

Can you explain how you wired up the manual switch? I hope you didn't provide power to the signal side of the relay......if so, that would be very bad for the PCM....


Do you still have your old relay? If so, then you might consider removing the relay from ebay and setting it aside for now. Take your AIH relay and put it where your GP relay was. Then put your old relay (the one that you recently removed) in the AIH spot. Wire everything back up like the photo I posted and see if your truck starts.

when wireing the manual switch you put the two bigger wires on the same terminals as the old relay. you put the two other wires to the side. then you put a jumper wire on the relay from theone big terminal that is always hot to one of the little terminals. then you put a wire from the outher little terminal on the relay to a momentary toggle switch and then you go from the other side of the momentary toggle switch to ground.

Ok good. That seems safe. The original wires to the small terminals were left OFF of the relay while the manual switch was installed. Correct?
How did you protect the wires while they were set aside? One of those would have full time power when the key is on...

taped them off

I think this is a good suggestion. Not being able to communicate with the PCM is a major clue.

Have you checked your fuel pump inertia switch? It's located behind the front passenger side kick panel.