Diesel Fuel Injection System Help Desk

**Dieseldude** · August 13th, 2008 10:00 AM

[SIZE=2]Could you also help me with this pls? [/SIZE]I will try.

[SIZE=2]I have a 1994 isuzu trooper (4JG2 engine) and i had the engine rebuilt 5 mos. ago. i have a problem with OIL & FUEL consumption. Are you still having the same problem after the overhaul? [/SIZE]

[SIZE=2]With regards to the oil problem, i noticed that the turbo has a lot of oil in it. some mechanics told me that they'll redirect the breather hose to the dipstick so that it wouldnt waste oil.. but is this really goin' to solve the problem? This is a remedy, not a solution. A good turbo may leak oil if your air filter is blocked as excessive vacuum will be applied to the intake system. [/SIZE]

[SIZE=2]Also with the excessive fuel consumption, i just had it calibrated too, nozzle tips were also replaced but it still consumes around 3-5 kms/liter. what are the causes, and wht should i do? Assuming that your pump and injectors were calibrated to spec by a qualified diesel workshop. The only remaining causes for high fuel consumption would be improper injection pump to engine timing, and/or a restricted air filter.[/SIZE]

I suggest that you first replace your air filter with an original Isuzu filter as this is a common denominator for both your concerns.

**rion** · August 15th, 2008 11:38 AM

With regards to the oil problem, i noticed that the turbo has a lot of oil in it. some mechanics told me that they'll redirect the breather hose to the dipstick so that it wouldnt waste oil.. but is this really goin' to solve the problem?

to think of it, I think it's not a good idea redirecting your pcv back to the dipstick because the dipstick also has positive pressure. imo, it's better vent it out with a oil catch can. as long as it is diesel engine.

**Dieseldude** · August 16th, 2008 10:09 AM

You are right Rion. Plumbing the blowby gasses back to the dipstick will raise the engine's air box pressure, which could push out the crankshaft seals. Remedy is to just drain out the gasses.

Aris' 4JG2 may have excessive piston & ring to liner clearance. A compression test will validate this. If the engine fails the compression test, the only correction is an overhaul........ again. Very expensive!!!!

**rion** · August 16th, 2008 04:49 PM

same thoughts too... basta bad oil/fuel consumption after a recent overhaul. I can only think of poor mechanic's work, usualy clearance related.

**soundman** · August 17th, 2008 07:30 PM

Hi, bro, I was reading the forum regarding diesel fuel injector and I find it interesting and might get some idea how to solve my problem with my Mazda B2200 pickup with RF01 engine. I just got it top overhauled / machine shops, due to cut timing belt, after the top overhaul, change all the valves and other parts, the oil and oil filter and put new baterry. The engine runs OK but with some problems.

FYI I was not using the car for 2 years.

1) Hard Starting - already replace new batterry, fuel filter, air filter and clean the fuel tank. What I notice is that after I keep the car in the parking for few hours, always there is air in the fuel filter. i have to bleed to remove the air, then it becomes easy to start.

2) Another problem is can not overtake, losing power when accelerating especially at 60 to 80 kph. Mechanic says, sliding clutch which I believe is not the problem, however, in short we change all the complete clutch ass'y, still the same problem losing power when accelerating.

Now I checked with calibration shop, they told me they need to overhaul the fuel injector which I know I have done it before. Now I have a doubt whether to go for the fuel injector or check other part of the engine. Calibration is not cheap they were charging me 5,500 PHP.

Clucth ass'y was replaced but nothing change in the engine performance, during idling the engine works fine but when accelerating it looks like the firing is delayed and ther is fuel restriction, even though it can not run, it consumes a lot of diesel.

Any advise is well appreciated.

Tnx. Alex

**avi42174** · August 18th, 2008 03:56 AM

hi everybody,

can someone give me an idea about my 2c engine, townace.. i,m having a problem with idling,, at first, idling is ok, but after a couple of minutes, the engine shakes at idle, much more if a/c is on.. water temp is normal.

i hope u can help me guys.. thanks

**Dieseldude** · August 18th, 2008 09:51 AM

get some idea how to solve my problem with my Mazda B2200..... I just got it top overhauled..... change all the valves and other parts, the oil and oil filter and put new baterry. The engine runs OK but with some problems.

1) Hard Starting - already replace new batterry, fuel filter, air filter and clean the fuel tank. What I notice is that after I keep the car in the parking for few hours, always there is air in the fuel filter. i have to bleed to remove the air, then it becomes easy to start. Copper gaskets on the pump's suction fitting could be damaged. Filter base may be leaking. Fuel suction line could be restricted due to a sharp bend or internal blockage. Leak is quite difficult to detect as plumbing from tank to pump is on a vacuum. You will have to do a complete trace on this line.

2) Another problem is can not overtake, losing power when accelerating especially at 60 to 80 kph. Mechanic says, sliding clutch which I believe is not the problem, however, in short we change all the complete clutch ass'y, still the same problem losing power when accelerating. Injection pump is probably pulling in air. Temporarily replace the rubber hose from the fuel filter to pump with a transparent hose. No air bubbles should be seen on this line with engine running.

Now I checked with calibration shop, they told me they need to overhaul the fuel injector which I know I have done it before. Now I have a doubt whether to go for the fuel injector or check other part of the engine. Calibration is not cheap they were charging me 5,500 PHP. Injector/s may need to be checked if the engine knocks or runs rough. Correct the air suction leak before considering injector service.

Clucth ass'y was replaced but nothing change in the engine performance, during idling the engine works fine (your injectors are probably ok) but when accelerating it looks like the firing is delayed and ther is fuel restriction, even though it can not run, it consumes a lot of diesel. Check injection pump timing. Does engine smoke? Black or white?

Any advise is well appreciated.

Tnx. Alex

You're welcome,

Dieseedude

**Dieseldude** · August 18th, 2008 10:06 AM

Originally Posted by avi42174

hi everybody,

can someone give me an idea about my 2c engine, townace.. i,m having a problem with idling,, at first, idling is ok, but after a couple of minutes, the engine shakes at idle, much more if a/c is on.. water temp is normal.

i hope u can help me guys.. thanks

Your problem may be similar to Soundman's. Replace fuel filter, then check your fuel suction circuit for air bubbles or restriction.

**soundman** · August 18th, 2008 12:11 PM

Originally Posted by Dieseldude

get some idea how to solve my problem with my Mazda B2200..... I just got it top overhauled..... change all the valves and other parts, the oil and oil filter and put new baterry. The engine runs OK but with some problems.

1) Hard Starting - already replace new batterry, fuel filter, air filter and clean the fuel tank. What I notice is that after I keep the car in the parking for few hours, always there is air in the fuel filter. i have to bleed to remove the air, then it becomes easy to start. Copper gaskets on the pump's suction fitting could be damaged. Filter base may be leaking. Fuel suction line could be restricted due to a sharp bend or internal blockage. Leak is quite difficult to detect as plumbing from tank to pump is on a vacuum. You will have to do a complete trace on this line.

2) Another problem is can not overtake, losing power when accelerating especially at 60 to 80 kph. Mechanic says, sliding clutch which I believe is not the problem, however, in short we change all the complete clutch ass'y, still the same problem losing power when accelerating. Injection pump is probably pulling in air. Temporarily replace the rubber hose from the fuel filter to pump with a transparent hose. No air bubbles should be seen on this line with engine running.

Now I checked with calibration shop, they told me they need to overhaul the fuel injector which I know I have done it before. Now I have a doubt whether to go for the fuel injector or check other part of the engine. Calibration is not cheap they were charging me 5,500 PHP. Injector/s may need to be checked if the engine knocks or runs rough. Correct the air suction leak before considering injector service.

Clucth ass'y was replaced but nothing change in the engine performance, during idling the engine works fine (your injectors are probably ok) but when accelerating it looks like the firing is delayed and there is fuel restriction, even though it can not run, it consumes a lot of diesel. Check injection pump timing. Does engine smoke? Black or white?

Any advise is well appreciated.

Tnx. Alex

You're welcome,

Dieseedude

*******************************************
Hi,

I noticed that there are bubbles in the intake hose, but after bleeding the air out it's gone, then when I parked the car for few hours again there is air. I already replace it before, I will replace again with a better transparent hose and will put 4 clamps in each hose.

I'll check the copper gasket, maybe it's sucking more air instead of fuel.

I will correct the air suction before doing the injector calibration.

( I told the mechanic to adjust the timing and try to advance a little bit but he dont want to, for what reaon I do not know, I will rotate the injector and make it advance firing a little bit

Engine does smoke but not so dark, it's more like grayish but not white.

Tnx alex
***********************************

**Dieseldude** · August 19th, 2008 01:59 AM

I noticed that there are bubbles in the intake hose, but after bleeding the air out it's gone, then when I parked the car for few hours again there is air. I already replace it before, I will replace again with a better transparent hose and will put 4 clamps in each hose. Dami naman clamp yan. One good clamp on each end should be okay.

I'll check the copper gasket, maybe it's sucking more air instead of fuel. Also, check the flat sealing surface of the banjo fitting.

I will correct the air suction before doing the injector calibration. Good.

( I told the mechanic to adjust the timing and try to advance a little bit but he dont want to, for what reaon I do not know. He probably doesn't know how to properly time the injection pump, and/or he doesn't have the necessary tool/s.

I will rotate the injector and make it advance firing a little bit. The correct procedure is to time the pump according to specs, as this will assure you of optimal power and fuel economy. Mahal na diesel, di bah?

Engine does smoke but not so dark, it's more like grayish but not white. Does engine smoke at low idle, or during acceleration only?