99 7.3 glowplug issues.

[94f450sd]

I havent really messed with many SDs.

The glowplugs and intake heater arent working.will not start unless plugged in.I put all 8 new motorcraft GPs in it a couple months ago.they still werent working.

Had a new GP relay.i swapped a known good used one into it.nothing.its got power at the big post and 1 small post.its not grounding the other small post to snap it on.if i ground it myself,the gp work.

Do these have a controller somewhere?if not,what should i be looking at to get it fixed?

Thanx

 

[IDIoit]

your engine grounds are bad?
these should be grounded, they have to be to work, as the relay is nothing but a switch.
i would check all of the grounds..
there should be a ground in the wirinf harness that bolts to the base of the relay.

 

[OLDBULL8]

There should be two wires going to the relay, one wire is hot all the time, the PCM does the grounding when called for. I'll check my 99 tomorrow, it's that way IIRC. There were changes made in 2001.

 

[IDIoit]

i was incorrect.

this is my 2001, relay is completely isolated.
but Bill says that the PCM does the grounding...

could it be a bad computer?

You must be registered for see images attach

 

[94f450sd]

There should be two wires going to the relay, one wire is hot all the time, the PCM does the grounding when called for. I'll check my 99 tomorrow, it's that way IIRC. There were changes made in 2001.

You are correct.the pcm is supposed to do the grounding but it isnt.would this be an oil or water temp sensor problem?

 

[OLDBULL8]

Oil temp sensor. Check oil level. 42 pin connector= pin 19 signal ground-- pin 17 engine oil temp signal EOT. check continuity between pins going to sensor not PCM.
There is a GP relay under the hood fuse box.

Easy way is to pull codes with an AE scanner.

Put your truck in your Sig. Is it a 99 or 99.5?

 

[94f450sd]

Got the plugs workin this morning.bad oil temp sensor.its not my truck,its a customers truck.im done with the diesels,gone back to my roots,pontiacs and gas engines.

Also needs injector orings i believe.gotta crank your balls off to get it to start even with either and block heater plugged in.gotta go see if the hpo reservoir is full or empty in the morning.

 

[trackspeeder]

Either injector O rings or IPR. High mileage on original injectors I would look at O rings.

 

[OLDBULL8]

CRANK CRANK CRANK to get it started, Check the ICP, if it has oil seeping out of it by the wires, it needs replaced, check the tin nut on the IPR, if it's loose tighten it, when loose it lets the solenoid coil possible slide back. You can check the ICP by disconnecting it, the PCM will take over the IPR pressure control then, if it starts quick, then the ICP is bad. It has to crank over pretty fast, needs 450 psi HPOP to start.

 

[94f450sd]

CRANK CRANK CRANK to get it started, Check the ICP, if it has oil seeping out of it by the wires, it needs replaced, check the tin nut on the IPR, if it's loose tighten it, when loose it lets the solenoid coil possible slide back. You can check the ICP by disconnecting it, the PCM will take over the IPR pressure control then, if it starts quick, then the ICP is bad. It has to crank over pretty fast, needs 450 psi HPOP to start.

Already done all that.im not a noob when it comes to a 7.3 psd or idi.

 

[OLDBULL8]

I don't know what you know, only giving suggestions.

 

[IDIoit]

my suggestion is to not use the blue towels as ass paper
(SORRY, INSIDE JOKE)

 

[trackspeeder]

my suggestion is to not use the blue towels as ass paper
(SORRY, INSIDE JOKE)

Are they softer than a Chiltons manual??

 

[madpogue]

Are they softer than a Chiltons manual??

Well they won't leave an ink stain.....

 

[IDIoit]

i heard they smoke better than the new testament.