GQ Injector replacement

Submitted: Wednesday, Apr 20, 2005 at 14:48
ThreadID: 22225 Views:10464 Replies:4 FollowUps:4
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Hi guys,
I want to replace my injectors for my turbo GQ 4.2 Diesel. Anyone out there know the following....

1 any difference between non turbo GQ injectors and turbo?

2 are the injectors in need of a torque setting or just tighten them up as much as possible within reason. If torque settings is required, what are they in either ft/lbs OR newton meters.

3 do they need to be bled and if so, how.

4 are there torque setting for the fuel lines that need doing or just tighten them up.

5 anything else i should be aware of before i go ahead and order the injectors?

6 apart from price, would u recomend reco or new injectors.

I can get them at trade price and it will save me some dollars. I know i can do the job, just wanted advice from those who know before i start the job. I dont think I need special tools either so im hoping the deep sockets will work for taking them out and replacing them. I havea tension wrench if needed.

Thankyou in advanced. I know between us all we can do anything involving 4wd's.
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Reply By: GUPatrol - Wednesday, Apr 20, 2005 at 16:22

Wednesday, Apr 20, 2005 at 16:22

All injectors for the TD42 engine are the same except for the very latest which has a sensor on no:1 for the timing correction.

They need a torque setting, its in the workshop manual.

They need bleeding although some people just crank it until it starts, the way to do it is crack open the piping (at the injector end) and crank it until you see diesel coming out on all, then close it and start it up, but don't rev it, it will missfire until all air has been pushed out of the injectors, let it idle and stabillise.

Would recommend new but they are very expensive, reco exchange is OK though.

AnswerID: 107557

Reply By: SteveL - Wednesday, Apr 20, 2005 at 17:53

Wednesday, Apr 20, 2005 at 17:53
I recently installed some changeover Hi-flo injectors. They were $442 for the set,which included all the copper washers needed to install them.Only took about an hour and a half fit.
AnswerID: 107569

Follow Up By: cokeaddict - Wednesday, Apr 20, 2005 at 17:56

Wednesday, Apr 20, 2005 at 17:56
Thanks steve, where did you get them from mate? Damn good price that. Do you remember the torque settings for the injectors?
FollowupID: 364450

Follow Up By: SteveL - Wednesday, Apr 20, 2005 at 18:05

Wednesday, Apr 20, 2005 at 18:05
I bought them from the Hi-Flo factory in Springvale, Vic. Sorry,didn't use a torque wrench :-(
FollowupID: 364453

Follow Up By: SteveL - Wednesday, Apr 20, 2005 at 18:09

Wednesday, Apr 20, 2005 at 18:09
Gregory's manual says 54-64 Nm. for the injectors.
FollowupID: 364454

Reply By: cokeaddict - Wednesday, Apr 20, 2005 at 18:10

Wednesday, Apr 20, 2005 at 18:10
Champion ..thanks so much mate.
AnswerID: 107573

Reply By: Whitbred - Friday, Apr 22, 2005 at 18:41

Friday, Apr 22, 2005 at 18:41
There is no physical difference with turbo to non turbo. The torque setting as per the book for the injector to the head is 54 - 64 Nm. You will need to by a tube socket though so you can do them up. They need to be bled by cracking the line at the injector and cranking the engine over until all the air is purged. The injector flare nut needs to be torqued to 20 - 25 Nm. The bleed off line is torqued to 29 - 39 Nm. I used to have a Safri Turbo Intercooled GQ, running around 16psi boost. One thing I was very particular about was the crack pressure. There is a company I used called Disel Tech, in Springwood QLD, and they would set all the injectors at 120 Bar by request. This is around 20 more than standard, (standard crack pressure is 100 to 105 bar), but it helps with better atomisation due to the increased combustion chamber pressure at higher boost. Even with a naturally aspirated engine, the crack pressures can be increased slightly (105 - 108ish bar) as this will help atomisation of the fuel in the pre combustion chamber. But more importantly , make sure they all crack at the same pressure, whatever you get them set to. I hope this helps you.
AnswerID: 107865

Follow Up By: cokeaddict - Friday, Apr 22, 2005 at 19:26

Friday, Apr 22, 2005 at 19:26
Thank you very much for your feedback mate.
Yes its very helpful indeed.
I found a company that will supply injectors with guaranteed genuine parts for $389.00. Damn good price considering they dont use china parts.

They can also supply a mobile mechanic that will do the job for $150. Saves me wasting the day doing it myself. I am still thinking of letting them do the job and sitting back and watching.

I will save your info for future reference though....Cheers
FollowupID: 364733

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