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Engine Specific Info and Questions => IDI Engine => Topic started by: BRimpossible on September 23, 2016, 11:31:03 pm

Title: Leaky injectors
Post by: BRimpossible on September 23, 2016, 11:31:03 pm
My 81 pickup runs ok but 2 injectors are leaking where the injectors are screwed in the head. Replaced one heat shield on one of them to see if it would stop. It still leaked after replaced. The injectors are brand new. This engine is NA 1.6. Any ideas to stop the leak?
Title: Re: Leaky injectors
Post by: RunninWild on September 23, 2016, 11:45:34 pm
Are they torqued properly? Maybe try cleaning the threads and injector holes and try again?
Title: Re: Leaky injectors
Post by: BRimpossible on September 24, 2016, 12:08:31 am
I'll try that. #1 injector would leak and weep fuel really bad and #3 isn't as bad but still it drives me crazy. Perhaps lapping the surfaces will help? I'm thinking to switch around the injectors to see if any changes
Title: Re: Leaky injectors
Post by: BRimpossible on September 24, 2016, 11:48:16 pm
Took the injectors out and the sealing surfaces are dirty on the head. How do I clean it and I want to lap it as well to give it an even sealing. Just having a hard time visualizing how it works.
Title: Re: Leaky injectors
Post by: fatmobile on September 26, 2016, 12:34:17 am
I have a heat shield on a small/long bolt.
 It has emery cloth stuck to it.
Stick it down the hole and spin with fingers.
Title: Re: Leaky injectors
Post by: libbydiesel on September 26, 2016, 10:03:40 pm
My 81 pickup runs ok but 2 injectors are leaking where the injectors are screwed in the head. Replaced one heat shield on one of them to see if it would stop. It still leaked after replaced. The injectors are brand new. This engine is NA 1.6. Any ideas to stop the leak?

Are you seeing liquid diesel at the base of the injectors?  If so, then it is leaking from above at either the seam of the two injector body halves, the small nipples, or the large union.  If you are seeing bubbles, it is because the liquid diesel that is leaking from above is getting hot enough to boil off. 
Title: Re: Leaky injectors
Post by: Rattlebox on September 27, 2016, 10:44:12 pm
I am leaning toward a leaky injector body also. any fuel actually coming out of the injector nozzle is burned and has no opportunity to leak out. The torque spec for the injector body and injector to cylinder head is 51ft/lbs.
Title: Re: Leaky injectors
Post by: Jetmugg on September 28, 2016, 05:18:28 pm
Try to eliminate the most common source of leaks first - the rubber "loop lines" that run from injector to injector are the first place to check.

Liquid diesel fuel is almost certainly not leaking from the heat shield surface backwards and upwards out past the threads.

Steve.
Title: Re: Leaky injectors
Post by: air-cooled or diesel on September 29, 2016, 08:45:39 am
1 way to clean head inj threads is with qtips, and brakecleen. if torque is correct (inj to head) check for injector body leaking, can come from the store leaky, and esp. as ^above^ #1 reason for leaks,,return lines, get some new,line, and a new return stop-off, in fact get 2 or 3. make sure you didnt/dont put heatshield(s) in backwards.
Title: Re: Leaky injectors
Post by: BRimpossible on October 01, 2016, 11:45:10 am
Thanks y'all for the reply. I'll get the surface contact on the head cleaned up and put injectors back in. I'll double check the injector body, nipple and rubber lines to make sure they aren't leaking. For now I'm taking a break from the rabbit for a bit after many problems it has caused for last few weeks.