'92 LJ78 Prado EFI fuel pump changed to manual pump - very low on power

[fazc76]

I have just acquired a 1992 LJ78 Prado showing 109000 KM, very clean and tidy - possibly genuine mileage looking at the condition.

It starts very well from hot or cold, no adverse smoke or irratic idle.

It is quite slow to build speed and feels very underpowered, it feels as if the turbo does not cut in - BUT I can hear the turbo spool up - it eventually gets up to 60 - 65 miles per hour - I have driven it 150 miles along the motorway at 50- 65 MPH.

It reduces speed on hills - no smoke problem.

Looking under the bonnet reveals a mechanical IP fuel pump, the Throttle position sensor on the inlet manifold is missing, there is a TPS on the pump but it is NOT connected, there are at least 5 connectors just dangling around the pump are - should be connected to something but this pump has no connectors for them.

I dont know what this pump is from, it apears to have 2 water pipes on the back which are NOT connected - I suppose they are cold start aid.

The green turbo light is on continously, rev counter does not work.

Fuel consumption is not too bad - 25 litres for 150 miles.

I have attached pictures in hope of some of you learned mudders may be able to advice in fixing this low power issue.

Thank you in advance.

 

[Scud1373]

the 2LTE engines are pretty underpowered so the slow starts and slowing down is normal. I have the automatic.

 

[Gun Runner 5]

Be careful not to over compensate for the lack of power by staying in the turbo. The high temps generated by the turbo can cause a host of problems on that engine. Go slow and enjoy the scenery.....................1978HJ45 ( 1990 LJ78 )

 

[fazc76]

I have had a few LJ78s over the years - so I know they are not the fastest machines on the road but this one is "super slow"

As you can see in the pictures it has a mechanical pump retro fitted, is there any way I can make adjustments to this pump / setup to get a little more power?

Would connecting the TPS sensor from the pump help at all - currently not connected (different plugs)

Can any of the other electric plugs be connected up to get more power (see pictures for many un-connected plugs / electronic connectors)

Thanks

 

[kbushnz]

Sounds / looks like someone fitted a std mech pump when the electronic pump should be there.
Or its had and engine swap and the 2L-T has gone in.
2L-TE Electronic controlled injector pump motor. ECU inside glove box.
2L-T Mechanically controlled injector pump motor.
As you have stated there are numerous connections loose and the TPS is not connected.
The ECU in the truck may be getting errors hence the turbo light on all the time.
Also if its an auto, (can see the auto dip stick) the ECU that controls the auto will be getting bad info also.
Don't get me wrong you can retro fit mech pumps but they are better suited to the manual trans models and also must be tuned to get the best out of them. Also the turbo may not be coming on boost properly.
I think you need to take it to a local diesel expert and show them under the hood.
The fix could be a used or overhauled Electronic pump.

Calvin

 

[fazc76]

Thanks Calvin - it is auto.

I have already been looking for an electronic pump as that is what it should have (found some on ebay £75 - £150 used)

would the 2.4td 2lte pump from the Hilux Surf fit this?

I was hoping for some info to tweak this manual pump to get more power - otherwise a used electronic pump will be fitted soon.

 

[pradocruzer]

Is the Prado standard or an automatic? If it is a auto, could the lack of power be a trans problem like starting off in second gear not first gear?? The ecm controlls the auto shift points and the major player for shift timing and load sensing is the TPS which is not hooked up and may be your problem. There are lots of dead 2lts around and I'am sure there will be a few good used injection pumps to be had. Like kbushnz said this may be the best way to go. You can tweek the the electronic pump and give a substantial boost increase to to get more power.
Take care.

 

[kbushnz]

Here is some info for you.
A great parts listing site.
Take a look, you may need to get a TPS for the throttle body.
2L-TE
Pump
ToyoDIY.com

Throttle body
ToyoDIY.com

Looking at this site the Surf / Hilux 2L-TE have the same part number as the Prado.
ToyoDIY.com

You are in for an interesting fix it job.

Here's what it should look like
http://home.mindspring.com/~hassy@ix.netcom.com/2LTEpump.jpg

Calvin

 

[fazc76]

Thankyou for your replies guys, much appreciated.

I think I will source a used EFI IP and fit that in.

Thank you.

 

[everbret]

It's been covered in other forums, but the reason the turbo light is on all the time is because of the MAP sensor that tells the ECU how much extra fuel to pump into the engine. Apparently over time these get worn out and pump fuel in at lower psi than is intended. Details are covered quite well in this Australian thread:

Toyota 4WD Surf Owners :: View topic - Fuel economy mod for $2

Cheers.

 

[fazc76]

OK so the situation is:-

The IP cannot communicate with the ECU as the IP is mechanical and does not have the electric connectors for ECU .....

What are my options to get the performance to improve a little with this current setup?

Are there any vac hoses I can swap / connect/ remove?

Has anyone else got this mechanical setup on their 2LTE? I would appreciate some pictures to see how yours is setup and compare mine.

Thank you

 

[fazc76]

By the way ....
as it has a mechanical pump ....doe this mean that it can safely use veg oil, cooking oil etc?

 

[Radd Cruisers]

We have done 3L conversions to replace the POS 2LTE.

The TPS hooked up is required for the trans to shift properly. If not there, the trans pressures may run up and the shifts may be hard and late. The TV cable needs to be hooked up.

Make sure there is a line going to the boost compensator on your IP from the same place that the line from the MAP sensor used to come from. If the BC is not getting pressure from the intake, then you will have very sleep performance.

If the hoses are hooked up, then you may need to add some fuel - either at the main fuel screw (try 1/8 turns at at time) or at the "smoke" screw on top of the BC.

I really dislike the 2LTE - and I can only hope that the engineer at Toyota that proposed this electronic design was forced to commit harakiri with a dull and rusty katana (and no, that's not bad karma on my part).


~John

 

[brettodpi]

this should work

Hi in response to the above offer i will agree that there should be a small rubber hose coming from the intake manifold somewhere. Preferrably from the now void map sensor or "turbo boost sensor". This will supply boost pressure to a pipe on the top of the pump (round top cover) which will in turn activate a rubber diaphragm inside the pump which activated a lever to increase fuel as the turbo increases pressure. That being said you may want to tweak the full fuel setting screw which is located just above the stop solenoid and towards the engine ( right side looking from injector pipes side). turn this screw in about a quarter turn at a time and continue to do so until you experience black smoke...then back out a bit till the smoke clears. Also try advance the pump slightly as the conversion from efi to manual often has a slight timing implication.

And the tps is needed for correct gear change on the auto boxes. check that the cable from the pedal to the intake manifold is there and working as the tps is usually activated there.

 

[crushers]

have you checked the timing of the pump?