Urgent help needed (diesel injection)

Submitted: Thursday, Oct 27, 2011 at 09:34

ThreadID: 89765 Views:4199 Replies:4 FollowUps:3

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Diesel Fuel Injection Systems

For drivers of petrol/gasoline-engined vehicles, fuel injection is a relatively new innovation. Only in the last decade or so has fuel injection become the norm and its predecessor,

chucky d

petrol was put into my work car and traveled about 5 klms til it stalled, the whole system was emptied out and replaced with diesel.
it runs smooth but when I rev it there is a knock in the top somewere, when cracking one off the fuel lines from the injector pump a diesel air mist is pumped out not straight diesel, this happens to only one fuel line.
when the line is cracked and is pumping the air/diesel mist out there is no knock at all when reving?????

it is a ford courier 2004 2.5 td

I would be extremely appriciative if someone could help me out with this.

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Reply By: chucky d - Thursday, Oct 27, 2011 at 10:24

Thursday, Oct 27, 2011 at 10:24

air is coming from engine not the injector pump.

AnswerID: 468628

Reply By: Ozhumvee - Thursday, Oct 27, 2011 at 11:06

Thursday, Oct 27, 2011 at 11:06

Petrol burns much hotter than diesel so it is quite likely that damage has been done to something in that one cylinder, burnt valve, burnt piston etc.
I'd be taking it to a diesel specialist not the local mechanic (unless he is a diesel mechanic) for expert diagnosis.
A little bit of petrol mixed with the diesel will do no harm but running a diesel engine on straight petrol is not good.
As it is a work vehicle then maybe it is "works" problem? Not your worry?

AnswerID: 468631

Follow Up By: Member - tojofixa - Thursday, Oct 27, 2011 at 21:34

Thursday, Oct 27, 2011 at 21:34

I would suggest you have a seized injector needle, these parts rely on the lubricating qualities of the diesel fuel to keep them operating.
Petrol does not have the same lubricating qualities and the injectors will be the first thing to seize if you run your engine on straight petrol.
You may want to have the injectors overhauled by a reputable diesel repair shop.
Hope this is some help.
Regards, Derek

FollowupID: 742993

Follow Up By: chucky d - Friday, Oct 28, 2011 at 09:08

Friday, Oct 28, 2011 at 09:08

yes makes alot of sense if injector is seized it would let air back through the injector and the air pocket creating the knock, sounds logical to me (but im a chippy not a mechanic) took the injectors out and dropped them at a diesel injection workshop to be reconditioned, guy thinks about $250 - $300 so if thats all the damage it's done i'm happy.

if that is all it has done would it be a good idea to upgrade the car? would it have done other damage that will haunt me???

thanks for all replies will drop another reply hopefully today when i try the recond injectors.

FollowupID: 743021

Reply By: lindsay - Thursday, Oct 27, 2011 at 21:26

Thursday, Oct 27, 2011 at 21:26

It will depend a lot on what type of engine it is and the compression ratio. I had a perkins diesel in a landrover years ago and the bloke at a servo in Alice put 4.5 litres of petrol in a 75 litre tank. He saidd he would drain the tank but I said it would be ok and that I would take it easy to the next fill. Well I cracked every piston , one you could put a hacksaw blade down. Then I know of a case where a diesel discovery filed a half full tank with petrol and drove home from Melbourne and only realised next morning when he could not start it. No damage was done. So it will depend on your motor. The mist may be still some air in one of the fuel lines. If you have cracked a piston you would probably have a high oil pressure and breathing heavily with lots of blue smoke.

AnswerID: 468675