• Advertisement

Max advance travel on injector pump reached, what now?

Get help fixing your Isuzu from other club members

Max advance travel on injector pump reached, what now?

Postby kirk332 » Thu Aug 10, 2023 11:23 pm

I have reposted this topic as I mistakenly put it in the wrong group, sorry about that. Newbie mistake!

Hi there,
New to the forum, new to diesels and diving in head first. Many questions!

I have a 1996 Jackaroo 4JG2 with turbo and inter cooler, does that make it a 4JG2-TC?

I have had problems with starting. Cranks for a while before firing then blows a heap of white smoke and idles roughly. Has a flat spot at around 3700rpm and runs out of pull.

All glow plugs test good.
Turbo is producing 12.5psi but I need to verify my gauge as it is an old one.

I have removed the injectors, dissembled, cleaned and in the process of reassembling. A bit of erosion on the body of the Jet but not too bad to cause issues I’m hoping. I’ll get them pressure and leak tested before installing.

How do you remove the washer in the head, seams to be a step washer pressed into the head? Also it doesn’t quite look like the new replacement washers I have which is just a flat copper washer. What am I missing?

I believe that injection timing is meant to be 0.019” (0.5mm) at TDC #1. Mine was set at 0.004”. Does that mean the timing has been retarded?
Anyways I adjusted the timing to 0.018” and I have reached the limit of travel for the pump….! Does this mean my pump is buggered, or is my timing belt in need of replacement, or am I doing something completely wrong? (Highly possible)!
I have removed and blanked the CSD so that it is out of the equation.

Any help appreciated.
kirk332
Isuzu Baby
 
Posts: 5
Joined: Sun Jul 30, 2023 11:39 pm
Age: 57
Country: Australia
City: Little Mountain
Vehicle: 8/1996 Holden Jackaroo UBS69 4JG2-T

Re: Max advance travel on injector pump reached, what now?

Postby geeves » Fri Aug 11, 2023 9:07 am

is the timing belt one tooth out?
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8978
Joined: Sun May 10, 2009 1:36 pm
Location: Rangiora
Age: 63
Country: NZ
City: Rangiora
Vehicle: 94 bighorn 4jg2
2013 Subaru XV

Re: Max advance travel on injector pump reached, what now?

Postby stardog » Sat Aug 12, 2023 9:45 am

Don't the jackaroos have timing gear and not a timing belt unless the motors been swapped over.
stardog
Isuzu Deity
 
Posts: 953
Joined: Tue Nov 10, 2009 6:14 pm
Location: sydney nsw australia
Age: 60
Country: australia
City: sydney
Vehicle: 96 wizard 3.1 top mount intercooler bulbar winch snorkel 2" lift front diff lock aftermarket transmission cooler.

Re: Max advance travel on injector pump reached, what now?

Postby geeves » Sat Aug 12, 2023 3:26 pm

Good point I have seen 1 4jg2 which was gear. Its in an Ausi assembled Bighhorn.
Sanding your knuckles before starting work can help. That way you cant skin them
User avatar
geeves
Site Admin
 
Posts: 8978
Joined: Sun May 10, 2009 1:36 pm
Location: Rangiora
Age: 63
Country: NZ
City: Rangiora
Vehicle: 94 bighorn 4jg2
2013 Subaru XV

Re: Max advance travel on injector pump reached, what now?

Postby paulthepilot5 » Tue Sep 12, 2023 7:22 pm

At 3700 rpm you are well past peak torque, they will fall over quickly after that. When you say you blanked off the CSD, what did you do exactly? I believe the CSD solenoid also functions as a metering orifice when not active, so if not replaced with a similar restriction may cause issues with timing advance. I would be first checking the gear timing is right, then confirm harmonic balancer hasn’t slipped prior to checking static timing on pump.
paulthepilot5
Isuzu Junior
 
Posts: 129
Joined: Thu Apr 05, 2018 8:56 pm
Age: 38
Country: Australia
City: Brisbane
Vehicle: 1995 Isuzu Rodeo 2.8d
Compound twin Turbo
12mm fuel Pump
+50 injectors
Water/meth injection

TF Rodeo ute 2WD short wheelbase
2.8 4JB1T
Inline injection pump conversion
+50 injectors
Borg Warner s200 turbo
300hp, 650nm

Re: Max advance travel on injector pump reached, what now?

Postby Roadrunner » Sun Sep 24, 2023 8:42 pm

kirk332 wrote:I have reposted this topic as I mistakenly put it in the wrong group, sorry about that. Newbie mistake!

Hi there,
New to the forum, new to diesels and diving in head first. Many questions!

I have a 1996 Jackaroo 4JG2 with turbo and inter cooler, does that make it a 4JG2-TC?

I have had problems with starting. Cranks for a while before firing then blows a heap of white smoke and idles roughly. Has a flat spot at around 3700rpm and runs out of pull.

All glow plugs test good.
Turbo is producing 12.5psi but I need to verify my gauge as it is an old one.

I have removed the injectors, dissembled, cleaned and in the process of reassembling. A bit of erosion on the body of the Jet but not too bad to cause issues I’m hoping. I’ll get them pressure and leak tested before installing.

How do you remove the washer in the head, seams to be a step washer pressed into the head? Also it doesn’t quite look like the new replacement washers I have which is just a flat copper washer. What am I missing?

I believe that injection timing is meant to be 0.019” (0.5mm) at TDC #1. Mine was set at 0.004”. Does that mean the timing has been retarded?
Anyways I adjusted the timing to 0.018” and I have reached the limit of travel for the pump….! Does this mean my pump is buggered, or is my timing belt in need of replacement, or am I doing something completely wrong? (Highly possible)!
I have removed and blanked the CSD so that it is out of the equation.

Any help appreciated.


I'd just re use the washers in the head, I've never seen an injector leak even though I've re used the washers on several different engines.
The white smoke is probably unburnt diesel, have a smell of it and see if it smells like diesel or engine oil. Chances are that the fuel pressure regulator is sticking which gives the white smoke out of the exhaust pipe. The regulator is a smallish bolt that sits at the front of the left topside of the injector pump main body, it isn't a hex head, it's a strange shape, like a round head with 2 flats cut into it. The low sulphur fuel that they make these days tends to make these older injection pumps stick a bit, I always throw a small amount of oil into the fuel tank when I fill it up, two stroke oil is good for this because it's low smoke, but 200 mills of engine oil works ok too (to a full tank). Before you try that, a good dose of diesel injector cleaner would be a good idea as it helps to dissolve gunk in the injection pump. If none of these things work you can make a socket to fit the regulator head and undo it, pull it out and clean it with a toothbrush and solvent of some kind, and make sure that it can be compressed and slides easily. The regulators often play up in winter, when there are lots of bugs (bacteria) in the fuel system I have found. The bugs leave a coating of bug shit on the injector pump components which also makes things stick. A good biocide would help here, at least in the winter months.
The injection pump uses fuel pressure to regulate the injection advance, so if the regulator is sticking the injection advance will be retarded when the engine is running, causing white smoke and low power/missing. Also, the bugs produce lots of bug farts, which is a gas and can build up to the point where the fuel filter will have to be bled, and this gas mixes with the diesel and finds its way to the injectors causing the symptoms you described. The easiest way to get more injection advance is to fit a small 12 volt 5 psi fuel pump before the fuel filter, and the 2nd easiest way is to adjust the cold start mechanism on the side of the injection pump, but you need an operative pressure regulator before playing around with these 2 other mods. You can also adjust fuel pressure by tapping in the small pin that lives in the centre of the pressure regulator a couple of mil. down. Don't go too far with this, because the regulator has to be removed to tap the pin out again so it's easy to go too far and have the engine "nail" which sounds like a sharp tapping noise when the engine is idling (not good for long engine life).
Roadrunner
Isuzu Baby
 
Posts: 20
Joined: Sat Sep 23, 2023 3:46 pm
Age: 50
Country: Australia
City: Central Victoria
Vehicle: 92 jackaroo, 4jg2 , ported turbo, 5psi lift pump, 11 psi boost, 5 speed, 4.3 diff gears.


Return to Engine

Who is online

Users browsing this forum: No registered users and 13 guests

cron