4JG2 Starting Woes

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4JG2 Starting Woes

Postby KG4PAM » Tue Mar 19, 2013 8:52 pm

Hi- I am having trouble starting the 4JG2 I am swapping into a Trooper. The engine is currently sitting on a pallet in my garage. I have loosened the lines at the injectors and cranked the engine over until fuel seeped out. I still cannot get the engine to run. I have power to the shutoff solenoid (obviously, or I wouldn't get fuel at the injector union). I can get the engine to fire if I spray a quick whiff of starting fluid. I have tried running the glow plugs for ~30 seconds, but it still wont start. Any ideas? I have tried everything I know to try with my limited diesel experience. The procedure I have described worked just fine with the 4JB1 I installed in my Jeep. I have read that the 4JG2 is slightly more finicky due to the indirect injection. I am beginning to wonder if the injectors may be completely stopped up- which would explain why I have fuel to the them, but no beans when trying to start. I have yet to remove one to see what it looks like.

Thanks for any help you can provide!

~J
2006 Hummer H3 Adventure package with 5spd... 70:1 crawl ratio, electric locker (for sale- $15k)
1981 Jeep CJ-7 with 4JB1TC diesel and MUA trans
1999 Trooper, winding down a 4JG2 swap.
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Re: 4JG2 Starting Woes

Postby JLEMOND » Tue Mar 19, 2013 11:07 pm

KG4PAM wrote:Hi- I am having trouble starting the 4JG2 I am swapping into a Trooper. The engine is currently sitting on a pallet in my garage. I have loosened the lines at the injectors and cranked the engine over until fuel seeped out. I still cannot get the engine to run. I have power to the shutoff solenoid (obviously, or I wouldn't get fuel at the injector union). I can get the engine to fire if I spray a quick whiff of starting fluid. I have tried running the glow plugs for ~30 seconds, but it still wont start. Any ideas? I have tried everything I know to try with my limited diesel experience. The procedure I have described worked just fine with the 4JB1 I installed in my Jeep. I have read that the 4JG2 is slightly more finicky due to the indirect injection. I am beginning to wonder if the injectors may be completely stopped up- which would explain why I have fuel to the them, but no beans when trying to start. I have yet to remove one to see what it looks like.

Thanks for any help you can provide!

~J


SOUNDS LIKE THE INJ ARE STUCK , IF THE ENG HAS BEEN SITTING FOR A LONG TIME , IF THE GLOW PLUGS A RE ON FOR 15 SEC ON 60 + DEGREES WEATHER AND YOU HAVE FUEL IT WILL FIRE RIGHT OFF, THOSE ARE 12 VOLT G PLUGS, MOST LIKELY INJ IF YOU ARE GETTING FUEL AT THE INJ INLET WHILE CRANKING . UNLESS YOU JUST DONT HAVE ENOUGH FUEL, AND THE PUMP IS NOT BUILDING PRESS . HOW ARE YOU GETTING FUEL TO THE INJ PUMP. DONT TRY AND START IT WITH A FUEL CAN SITTING ON THE FLOOR , GET THE CONTAINER UP AS HI AS YOU CAN SO IT CAN GET A GOOD GRAVITY FEED , IF THE PUMP HAS BEEN SITTING A LONG TIME , IT MAY NOT HAVE ENOUGH INITIAL SUCTION TO GET FUEL INTO THE PUMP.AND FILL THE PUMP HOUSING
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Re: 4JG2 Starting Woes

Postby KG4PAM » Wed Mar 20, 2013 12:37 pm

I am getting fuel to the pump by using a gravity feed container sitting on top of the engine. I have another container under the bypass to catch return fuel. It does seem like there is an excessive amount of fuel coming out of the return when cranking- when i 'bench tested' by 4JB1, the return didn't flow that much. On this engine, there is a very steady stream coming out of the return- almost like the fuel is just running straight through the injection pump and out the bypass.

What is the best way to clean the injectors, assuming that is the issue (seems most likely to me)? Can I just remove them from the head and soak in Marvel Mystery Oil or kerosene? This has to be what the issue is- it will run for a second or two with a bit of starting fluid, then die. I obviously don't want to try much starting fluid very often, but at least it helps troubleshoot the issue.

Thanks!
2006 Hummer H3 Adventure package with 5spd... 70:1 crawl ratio, electric locker (for sale- $15k)
1981 Jeep CJ-7 with 4JB1TC diesel and MUA trans
1999 Trooper, winding down a 4JG2 swap.
KG4PAM
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Location: Lenoir City, Tennessee
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Re: 4JG2 Starting Woes

Postby JLEMOND » Wed Mar 20, 2013 3:59 pm

KG4PAM wrote:I am getting fuel to the pump by using a gravity feed container sitting on top of the engine. I have another container under the bypass to catch return fuel. It does seem like there is an excessive amount of fuel coming out of the return when cranking- when i 'bench tested' by 4JB1, the return didn't flow that much. On this engine, there is a very steady stream coming out of the return- almost like the fuel is just running straight through the injection pump and out the bypass.

What is the best way to clean the injectors, assuming that is the issue (seems most likely to me)? Can I just remove them from the head and soak in Marvel Mystery Oil or kerosene? This has to be what the issue is- it will run for a second or two with a bit of starting fluid, then die. I obviously don't want to try much starting fluid very often, but at least it helps troubleshoot the issue.

Thanks!


REMOVE THE INJ AND PUT THEM IN A CONTAINER OF LACQURE THINNER OR ACETONE , AN DHOPE THAT IT WILL DISSOLVE THE MOST LIKELY DRIED UP FUEL THAT HAS LEFT A STICKY RESIDUE , IF THAT DOESNT LOOSEN THEM UP YOU WILL HAVE TO HAVE THEM DISSASEMBLED AND RESET . IF YOU TAKE THEM APART DO NO MIX THE NOZZEL PARTS WITH THE OTHER INJ. THEY ARE HAND FIT TO EACH OTHER AND WILL NOT WORK CORRECTLY THE SPRING AND PLUNGER AND ADJUSTING SCREW OR SHIMS SHOULD BE KEPT WITH THE INDIVIDUAL INJ. ALLSO
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Re: 4JG2 Starting Woes

Postby KG4PAM » Wed Mar 20, 2013 9:28 pm

Ok. I finally got one injector out- going to have to buy a deep well 22mm socket to get to the others. How often do the nozzles need to be replaced? I am putting together an order with Frank over at Trooperspares. Thinking about adding complete injectors or nozzles to the list, but would obviously like to not have to considering how expensive they are.

Do I need to replace the aluminum gasket when I reinstall them?
2006 Hummer H3 Adventure package with 5spd... 70:1 crawl ratio, electric locker (for sale- $15k)
1981 Jeep CJ-7 with 4JB1TC diesel and MUA trans
1999 Trooper, winding down a 4JG2 swap.
KG4PAM
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Location: Lenoir City, Tennessee
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Re: 4JG2 Starting Woes

Postby KG4PAM » Wed Mar 20, 2013 9:29 pm

(aluminum gasket between injector and "leak off pipe")
2006 Hummer H3 Adventure package with 5spd... 70:1 crawl ratio, electric locker (for sale- $15k)
1981 Jeep CJ-7 with 4JB1TC diesel and MUA trans
1999 Trooper, winding down a 4JG2 swap.
KG4PAM
Drives on Dirt
 
Posts: 68
Joined: Tue Oct 02, 2012 1:26 pm
Location: Lenoir City, Tennessee
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Re: 4JG2 Starting Woes

Postby JLEMOND » Wed Mar 20, 2013 10:24 pm

KG4PAM wrote:(aluminum gasket between injector and "leak off pipe")


PROB , CAN REUSE THE RETURN LINE SEALS THEY SHOULD BE COPPER NOT ALUMINUM, THOSE INJ HAVE TO HAVE THE PRESS SET USING SHIMS , CAN BE TIME CONSUMING. I WOULD TAKE YOUR S APART AND SEE ABOUT CLEANING THEM UP AND PUT THEM BACK TOGETHER EXACTLY LIKE THAT COME APART AND S EE HOW IT RUNS. IF THE NOZZELS ARE STUCK , THEN SEE ABOUT NEW ONES, ,NEW NOZZELS WILL REQUIRE RESETTING THE PRESS , MOST LIKELY
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