Thread: 4J engine tech - and a crazy idea!

still dont know what you want to do with this ben seen your looking for one so whats the 3lt di in the late tf early ra deos then

ps if you can find one in the easten states i can pick up in march

The combustion chambers in the pistons and the injectors have to match. You would need to verify this by comparing the pistons to those from a 4JB1T.

A lot of Isuzu's have the squarish combustion chamber and the injectors are designed to spray into each of the corners.

I have heard of 4BD2T being converted to DI in the USA using head and pistons from a 4BD1T. This is more driven by the 4BD2T being prone to crack heads.

Originally Posted by Bush65

The combustion chambers in the pistons and the injectors have to match. You would need to verify this by comparing the pistons to those from a 4JB1T.

A lot of Isuzu's have the squarish combustion chamber and the injectors are designed to spray into each of the corners.

I have heard of 4BD2T being converted to DI in the USA using head and pistons from a 4BD1T. This is more driven by the 4BD2T being prone to crack heads.

Thanks John - apparently the 4JG2 cracks heads as well...

You have other options too.

The 4JH1 is the 3.0 DI engine fitted to the rodeo utes.
The 4JX1 is the 3.0 unit injector motor fitted to later jackaroos/troopers/bighorns, worth checking the bore and stroke on those.
The 4JJ1 is the 3.0 commonrail engine currently used.

Try to find a complete 4JH motor.

The complete older bighorns here (4JB1T & intercooled) are now under $1500 here for a complete vehicle. One of my mates has an auto 3.1 bighorn, if it gives any greif he should just throw the entire driveline from the earlier models in.

Double post...

Originally Posted by Dougal

You have other options too.

The 4JH1 is the 3.0 DI engine fitted to the rodeo utes.
The 4JX1 is the 3.0 unit injector motor fitted to later jackaroos/troopers/bighorns, worth checking the bore and stroke on those.
The 4JJ1 is the 3.0 commonrail engine currently used.

Try to find a complete 4JH motor.

The complete older bighorns here (4JB1T & intercooled) are now under $1500 here for a complete vehicle. One of my mates has an auto 3.1 bighorn, if it gives any greif he should just throw the entire driveline from the earlier models in.

Thanks Dougal!

OK, the engine list:

Engine / BorexStroke / Inection / Valves / Application

4JA1 / 93x92 / DI Bosch VE / 8 OHV / Import TF rodeos (EU/Japan market)
4JA1-L As above, turbocharged variant for EU Isuzu D-Max
4JB1(-T) / 93x102 / DI Bosch VE / 8 OHV / TF Rodeos (1988-2002)
4JG2-TC / 95.4x107 / IDI Bosch VP 29/30 Electronic? / 8 OHV / Jackaroo 1992-1997
4JG1(-T) / 95.4x107 / Bosch Zexel type A / 8 OHV / Industrial/Marine
4JH1(-TC) / 95.4x104.9 / Bosch VP44 Electronic / 8 OHV / RA Rodeo? Isuzu NKR200 (Sitec 125)
4JJ1(-TC) / 95.4x104.9 / EFI / 16V DOHC / Colorado/D-Max / ISUZU NxR 200 (current)
4JX1(-TC) / 95.4x104.9 / EFI / 16V DOHC / Jackaroo 1998-on


This is just so weird...



The 16v engines are likely no use (not that I have seen pictures of the pistons). The 4JH1 looks like a nice engine! It has recently been superceeded by the 4JJ1-TCS in ISUZU trucks:
http://www.aulro.com/afvb/isuzu-land...00_ARK0207.pdf

Just a shame about the Injector pump:

A number of vauxhalls and Saabs from late 2002 use a VP44 PSG16 injection pump. This pump is very fragile and VERY costly to replace (currently it is not repairable) because of this we DO NOT supply any tuning device to increase power of an engine fitted with this pump.

Diesel Bob Tuning - VP44 with PSG16

BOSCH VP44



Easy to identify, there is no mechanical connection to the pump from the accelerator pedal, and very small cast flange to which the high pressure delivery lines attach. It is a compact and very capable pump when working correctly, often being used in very large applications such as buses and lorries, as well as Ford Focus to name but one!.

The VP44 is a fully electronic controlled pump. Early units had two ECU 's one internal to the pump and an external engine or vehicle mounted unit. Later pumps combine both ECU's in the pump case.

Being still relatively new, and untill recently, no service information or spare parts has been available, little is known as to its capability for use on Vegetable oils. Issues of pump problems associated with Biodiesel have been reported, where the methanol content attacks internal position sensors.

What is known, of failures on Diesel fuel, suggest a lubrication issue of the distributor rotor similar to the Lucas/CAV series. In common with the Lucas pumps, Fuel and hence lubrication is cut off to the rotorhead during conditions of overrun (engine braking)

Research also suggests any restriction in fuel supply to the pump, for instance a partial filter blockage could also cause damage to the pump, through lubrication starvation.

Early models were quite prone to failing on Diesel, and the distributor rotor assy, has been through three different updates since the pump was first made. Later pumps are therefore more reliable in this respect, but care must be excersised if attempting the use of Vegetable oils with these pumps.

-Ive just received a VP44, that Ive recently won on Ebay for the huge sum of 99p! It is intended for a Volvo FL250 Tractor Unit, and was manufactured late February 03, but I have other plans for it, such as a full strip-down and assessment for Vegetable oil use!

A preliminary inspection has been carried out, and found that the distributor rotor is of a similar size to the Lucas/CAV series, and as such, will probably cause trouble with cold oils

There appears to be a similarity in construction to both the Lucas/CAV, DPC and the Stanadyne DB 2 series

The Position Sensor appears to be a Hall-Effect device, similar to that used in Video Recorders, where they are used as reel-table rotation sensors. It is connected to the main FPCU ( fuel pump control unit, mounted at the top of the pump) by a rather delicate ribbon cable, of the type commonly used in Domestic Electronic equipment At present it is not understood what effect Methanol has on this sensor. If anyone has a VP44 position sensor thats failed on BioDiesel, --Please contact me so as I can compare it with a known good sensor to find its failure mode.

Sensor update, The Position sensor appears to be a set up of three coils, and not a Hall effect device as previously thought. The Average DC resistance of these is around 77-85 ohms.

A suspect dead VP44 pump can be tested before removal from the engine by first disconnecting the main plug, and locating pins 6 and 7. These are at the right hand side of the socket on the pump when looking at the socket with the pump top uppermost. The pins are numbered in the socket.

Connect a lead from a good earth or Batt - to pin 6

Connect a lead from Batt + to pin 7, Make sure the lead has a good contact, and capable of passing up to 30A, also, make sure it wont come loose when the engine starts, Dont allow it to come into contact with any other pin, or earth while connected to the battery!

tie back the plug that normally goes to the pump, to prevent shorts.

Operate engine starter, If engine starts and idles correctly, then there is a good chance the pump is fine.

Most problems are associated with bad connections, as some pass high currents which are prone to trouble. The contacts in the pump plug can work loose, but can be tightened carefully with a very small screw-driver.

Veggiediesel.co.uk - The home of H.C. II
VP44 Inj Pump Reliability

So I suppose what I would really like is a 4JH1 with a Bosch VE pump... or a DI-converted 4JG2...

But a 4JB1 would do the job as well, with a lot less fiddling around... Dougal - I wish they were as cheap over here - It would probably be cheaper to ship a 4JB1 from NZ than buy one here!

My work car has a VP44 injection pump. I'm not sure how hard it is to fit a manual VE pump in their place. Since the early 4JG2's were fully mechanical and the later ones were electronic it's possibly just a bolt in.

Actually there's probably more info around on VE vs VP44 pumps in the VW tdi world than anywhere else.

You could retrofit the entire wiring harness from a rodeo into your series. Sure it's completely against the point of driving a series but if this guy can do it wtih a nissan, you can too:
trinituner.com :: View topic - AD wagon

The above one wasn't the one I was looking for. Someone else swapped the complete diesel/auto front transaxle with wiring etc into an older nissan.

Originally Posted by Dougal

My work car has a VP44 injection pump. I'm not sure how hard it is to fit a manual VE pump in their place. Since the early 4JG2's were fully mechanical and the later ones were electronic it's possibly just a bolt in.

Actually there's probably more info around on VE vs VP44 pumps in the VW tdi world than anywhere else.

You could retrofit the entire wiring harness from a rodeo into your series. Sure it's completely against the point of driving a series but if this guy can do it wtih a nissan, you can too:
trinituner.com :: View topic - AD wagon

The above one wasn't the one I was looking for. Someone else swapped the complete diesel/auto front transaxle with wiring etc into an older nissan.

Hmm - it seems people have done similar things on rover car diesels... (or at least talked about it...)
Converting Rover 45 to older Bosch pump? - MG-Rover.org Forums

I could fit the wiring harness, true, but if I was going to bother fiddling with EFI I would go the whole hog and install a 4JJ1-TCS - 114kW and 388Nm of torque in stock, unchipped form