PDA

View Full Version : Duramax with Air in fuel system?



portcity05
05-11-2011, 03:59
Hi
I am having to bleed air from the fuel system at an ever increasing interval in my 2500HD Duramax.
It started shortly after replacing the injectors, we had no problems for the first 5000km or so but then after a 1000km trip over-night towing to Murrray Bridge speedway in South Australia and back home we found the next day that the engine started and ran for about 5 seconds and then stopped and would not re-start.
After I bleed the fuel of air it started right away.
Since then it has accured at a more increased interval, to the point it now accurs after driving to work which is only 8km and the again the next morning, no sign of any leaks.!!
I am going to purchase and fit a fuel lift pump from the Duramax guru, but in the mean time I am interested if anyone has had a similar problem.??
I have taken a look, but no obvious reason.??
regards Terry

Kennedy
05-13-2011, 09:23
Air in the fuel is very common with most all Dmax's. It's not there for teh reason that many air removal "Specialists" think that it is, but it's not a good thing. Adding a lift pump will take care of 99% of your air issues assuming there is no major mechanical deficiency like a leaky line etc.

I have set up some simpler "Deluxe" lift pump kits on my site to help.

portcity05
05-16-2011, 01:02
:) Hi
We found the air leak in the fuel system, the filter head inlet pipe had been modified when it was converted to RH drive by MCI in Melbourne, just another stuff up that is now rectified.
The pipe had been welded and then painted to cover up the repair, I removed the system and pressurized it to 15LB then submerged it in water to find a stream of bubbles.
I repaired the pipe with belzona.
I am guessing the problem has always been there and has now become worse, hence 2 sets of injectors in 150,000 km.
thanks for your input.
regards Terry

More Power
05-16-2011, 10:09
Good job on finding the air leak. I sometimes recommend pressurizing the fuel tank with 5 to 10-psi, using regulated air pressure, to find a leak. Pressurizing the fuel tank will produce a slow oozing fuel leak at the site where air is entering the system - helping you to locate the leak site in just a few minutes.

A small air compressor with a regulator works well. Just wrap a clean oily rag around the air nozzle and stuff it into the fuel filler neck. Don't use more than 5-10 psi...

Jim

deerhunter7
05-17-2011, 04:59
I would consider Belzona a temp fix. The Utility I work for used it for years and I have been for years going to Substations cleaning off the Belzona and welding the leaks . Does not work long term as oil slowly works its way through..