Help Needed changed glow plugs now rough idle at startup

[Tail_Gunner]

i am trying to get a game plan for the morning, i cannot understand why it ran fine 24hrs ago and jst had glow plug trouble fixed. now thats fixed and somethin else is wrong somwhere. i am going to change the fuel filter in the morning and buy a fuel pump just in case. is it possible to bleed air from this system.

No way I'm aware of to bleed air from the fuel rail in the heads.

As for priming the pump, I've heard one trick is to hook a shop vac up so it blows instead of sucking. Then remove the fuel (gas) cap and press the blowing hose up to the filler neck. That will apply a slight pressure to the fuel in the tank and push fuel up to the pump priming it.


FWIW, When you replaced the glow plugs, did you remove the valve cover gasket and wires? Or did you leave the gaskets in place and just unplug each glow plug wire? I am wondering if you may have dislodged the UVC connector(s) when you did your glow plug project..

 

[JLDickmon]

i am trying to get a game plan for the morning, i cannot understand why it ran fine 24hrs ago and jst had glow plug trouble fixed. now thats fixed and somethin else is wrong somwhere. i am going to change the fuel filter in the morning and buy a fuel pump just in case. is it possible to bleed air from this system.

nuh-uh.
it's a return-less system.
other than driving it, no provision for air purging.

 

[JLDickmon]

FWIW, When you replaced the glow plugs, did you remove the valve cover gasket and wires? Or did you leave the gaskets in place and just unplug each glow plug wire? I am wondering if you may have dislodged the UVC connector(s) when you did your glow plug project..

good point.
If that's when the problem started, go back there and have a look.

 

[Bad Night]

good point.
If that's when the problem started, go back there and have a look.

My thoughts exactly , go back to it ran fine until I ....... and see what you can find before throwing a bunch of money at it . I have also heard that the wiring harness for the injectors is easy to break due to it corroding and getting weak and brittle . It runs through the valve cover gasket (i know most everyone know that ) and I've been told be careful not to damage it when accessing the injectors and glow plus .

 

[sagebel]

Pull the valve covers and check all the connections. You may have bumped one of the injector connections loose. Also check the flat connector on the valve cover gaskets.

 

[Tail_Gunner]

If ur gonna go back in there, might as well get the little locking wedges that keep the UVC connectors from coming apart.

UVC Connector locks

 

[AKTIVE1]

thanks for all the hints to look for, i ll answer them 1 by 1. i did not remove the valve cover gasket, i left it on the head. the valve cover wiring deal already left me stranded two years ago on my way to opening night race pulling a 40 ft enclosed, had everthing towed back to the shop , then sent the dually on a rollback to the dealer to be fixed, that bill hurt! is it possible for the valve cover connection to go bad in 2 yrs. i am going to go back thru everthing tomorrow. i am still wondering where that 2 pole plug goes that was laying in the valley. its still attached to the harness but i cant see if it goes to anything. its only 8 inchs long and there are no sensors left to hook it to. welll i did all 8 glow plugs in 4 hrs while watching my 5 and 3 yr olds, maybe i can do it a little easier tomorrow. lol thanks again everyone! ill give the results in the afternoon.

 

[BIG JOE]

thanks for all the hints to look for, i ll answer them 1 by 1. i did not remove the valve cover gasket, i left it on the head. the valve cover wiring deal already left me stranded two years ago on my way to opening night race pulling a 40 ft enclosed, had everthing towed back to the shop , then sent the dually on a rollback to the dealer to be fixed, that bill hurt! is it possible for the valve cover connection to go bad in 2 yrs. i am going to go back thru everthing tomorrow.[ i am still wondering where that 2 pole plug goes that was laying in the valley. its still attached to the harness but i cant see if it goes to anything. its only 8 inchs long and there are no sensors left to hook it to.] welll i did all 8 glow plugs in 4 hrs while watching my 5 and 3 yr olds, maybe i can do it a little easier tomorrow. lol thanks again everyone! ill give the results in the afternoon.

That 2 pole Plug... might be the EBPV pigtail.. look under the front of the turbo/Y pipe area... if you see an open 2 pin plug-in ? thats where it goes..

Joe

 

[AKTIVE1]

hello joe , thanks for the reply , i'm not familiar with all the abreveations yet, what does that one stand for and would it have a snap clip to lock it from coming loose and what does it do, thanks allan

 

[BIG JOE]

hello joe , thanks for the reply , i'm not familiar with all the abreveations yet, what does that one stand for and would it have a snap clip to lock it from coming loose and what does it do, thanks allan

EBPV: Exhaust Back Pressure Valve. It's part of the "Cold engine start" circuit.... closes, to hold some heat back.. for faster warm up.

If I remember correctly (IIRC).. the plug IN part has a clip.

Joe