Builds Lees LJ78 Prado Build (1 Viewer)

[Lee777]

I feel like ive been to war with this truck. About 7 years ago I bought it unaware of the "design issues" and ended up replacing the engine (it turned out it had a crack in the head). I got a bad taste in my mouth, had it up for sale for a while and no bites. I took it off the market and it sat in the back yard for a while. I got back into IH8Mud and noticed there was a lot more information cool mods that could be made. I have the bug again ( or affliction, if you will) to get wrenching again! My son is 8 yrs and we had fun firing er up again. Changed the oil and got it insured. It takes 15 cranks to cold start but once its running for the day, it starts no prob. So great to be driving this truck again! More posts to come. Thank god for ih8mud because I cant do this myself, lol

 

[Lee777]

Purchased with:
Boost, temp, and EGT gauges
Non functional hub locks
Engine with cracked head
Clogged rad

Improvements/maintenance

Replaced with used engine from a surf (2010)
New rad, water pump, belts (2010)
Manual hub conversion (allen screw gear mod)
Exhaust front to back (2010, 2014)
Front axle service and brakes (2015)
Rear brakes and seals (2014)
Rear diff housing removal, new gasket, and prop shaft seal (2014)

To do list:

1)Fix steering (currently drivable but steering is hard when turning right at crawling speed, also noise from steering pump pully i think)

2) Fix egt guage, it stops working after 30 min of driving , thinking its a faulty ground cable.

3) Delete EGR

4) Delete AC components and AC radiator

5) Delete existing air filter/intake and replace with conical High fliw filter

6) Clean out sludge in air intake

7) Rebulid turbo

8) Replace glow plugs

9) rebuild fuel pump? (It sometimes leaks fuel, 1 drip per 10 seconds, but then stops, behavior is intermittent

10) Intercooler to cool turbo air.

 

[cruiserpilot]

Glad to see you're back. I used to spend a lot of time in Salmo, great town. Almost
bought a place there, wish I had. Lots of guys here with that truck now.

 

[Jarrat]

Sweet!, another LJ in BC!!! Can't wait to see the progress pics.

 

[GTSSportCoupe]

Glad to hear you are getting back into it! Sounds like you've got a good start on it already.

One of the things i've been preaching to the 2LTE crowd is to convert to Evans Waterless Coolant. I use it, and highly recommend it. It will keep more even temperatures in your cylinder head and help a great deal to prevent the head from cracking. It's a relatively small investment, but makes such a big difference. It also doesn't boil until 375F. No more overheating issues.

Did you keep your old motor for spare parts?

A few comments on your 'to do' list:

1)Fix steering (currently drivable but steering is hard when turning right at crawling speed, also noise from steering pump pully i think)

Are you using the Prado or Surf power steering pump? Don't know if they are different, just a thought... Did you use Dexron III when you filled it back up after the engine swap? Does it need a flush? There is a procedure here on mud (maybe in the 60 series section...I'd have to look again) on how to flush, but basically it can all be done at the reservoir by removing a hose and putting it in a bucket. Add clean fluid to the reservoir and the old fluid will pump into the bucket with the engine running. Keep doing this until it comes out clean. I did this recently and it worked out well. My old fluid was brown, new is red now.

3) Delete EGR

This is a great mod. While you do it, remove the VSV's and emissions throttle plate at the same time. You might also consider removing the main throttle plate. It gives a lot more low end torque among other advantages. Really cleans up the engine bay too.

4) Delete AC components and AC radiator

This really helps airflow to the rad, and is a great idea if you don't need A/C. It also makes a lot of room for a nice sized front mount intercooler. I like this one that pradocruzer did: How to Install a Intercooler on a '91 Prado EX5 (2L-TE)?

5) Delete existing air filter/intake and replace with conical High fliw filter

If you plan on running dusty roads, keep the factory air system. It creates a vortex in there and the dirt ends up in the lid. Works very well. If you want more airflow, there is a K&N filter that will fit in the factory box and definitely flows better (I have one). Still a good idea to swap a paper on in if you plan on lots of dusty roads though.

6) Clean out sludge in air intake

I had a problem with that too. It's from the EGR and PCV mixing. You will find it is probably on the intake ports to the head and on the backs of the valves too. Try to clean it all out if you can. It's hard, but worth it.

7) Rebulid turbo

Whats wrong with it? If it looks oily inside on the compressor side, it's probably just PCV gunk in there? If there is oil out the turbine side, then it probably does need new seals. How is the in/out side/side play? There should be almost no in/out and just a bit of side/side.

9) rebuild fuel pump? (It sometimes leaks fuel, 1 drip per 10 seconds, but then stops, behavior is intermittent

This seems to happen to all the JDM rotary injection pumps around this age. It likely does not need a full rebuild, but just needs new seals. I bought a seal kit from ebay uk and did this job myself to save money. Worked well with no more leaks. A fairly big job though. Most of the labor is just getting the pump off and back on again.

10) Intercooler to cool turbo air.

Intercoolers make such a huge difference to these motors! A great improvement. Lowers the EGT's by a huge amount, allows you to make a lot more power by turning up the boost and fuel (safely).

It's worth the effort! These trucks are pretty bullet proof besides the factory engine setup. Improve the factory engine (as you intend ^^) and you'll have a great truck! I look forward to seeing how it all works out for you. Click 'Build' in my signature to see a list of some of the stuff I've done to mine. A little over the top, but it runs great.

 

[Lee777]

Hey GTS!

Great suggestions to enhance the plan of attack. Im going to try the power steering flush soon and see what happens.

Good to hear the fuel pump issue is common. I was wondering if it was causing probs with cold starts. I have some glow plugs on order from Radd Cruisers. We'll see If that helps with cold starts.
I guess i could check the injectors too. Plans, plans, plans..

Thanks again

 

[GTSSportCoupe]

Hey GTS!

Great suggestions to enhance the plan of attack. Im going to try the power steering flush soon and see what happens.

Good to hear the fuel pump issue is common. I was wondering if it was causing probs with cold starts. I have some glow plugs on order from Radd Cruisers. We'll see If that helps with cold starts.
I guess i could check the injectors too. Plans, plans, plans..

Thanks again

Hey Lee, I found the thread with the power steering flush 'how to': How to replace power steering fluid (with pictures)

And yes, if diesel is leaking out of your pump, then air will be getting in. Here are some pictures of when I changed all the seals: Resealed my rotary injection pump The kit was only about $40 from the UK.

 

[Lee777]

I managed to get the power steering fluid flushed and no surprise the steering is far better. Before the flush there was a sound coming from the pump when steering hard left or right. That sound has disappeared. I put the front axle on blocks. My first attempt at a flush involved disconnecting the high pressure line from the reservoir and connecting it to a clear piece of tubing which went into a empty 2L plastic bottle. The plan was to continuously add fluid into the reservoir and have the old fluid flush out the tube into the 2L. When I fired up the truck, the clear tube connection seen in the picture blew and I had made a fluid geiser. So much for that. So I reconnected the system and went the usual route (filling the reservoir, turning the wheels, emptying reservoir, then adding new fluid). KISS principle prevailed (EDIT< just read the post proposed by GTS to change out fluid, I chose the wrong line.. should have been the low pressure line, LMAO )

Being a novice, I'm not quite sure how to plumb in my boost controller. Below is a marked up photo of my current setup. May I have some help with how to connect in the boost controller. I drew in where I think its supposed to go. What is A, B, and C of this current setup and how would I plumb in the boost controller?

Boost controller

New glow plugs are in the mail. I plan to change out the plugs along with the EGR/Throttle plate delete. I have some 17 gauge sheet metal, I'm hoping its thick enough to fab some block off plates.

 

[GTSSportCoupe]

I think the 'C' line probably is going to your boost gauge? It is not factory anyhow.... If it is the boost gauge, you could leave it connected there, or you could run it over to the intake manifold, and split off the line that goes to the boost sensor. This will give you a more accurate boost reading once you've intercooled the motor.

If you left the lines as they are, your boost controller would go in the 'B' line. The bottom of the boost controller (as per your pic) would go towards the 'C' or outlet nipple of the turbo. The side of the boost controller (as per your pic) will go towards the wastegate.

Don't run more than about 12psi without an intercooler. You might also consider getting a bleed off device to put in before your boost sensor. This would allow you to trick the computer into thinking the boost is lower than it is. This means less fuel which will mean cooler EGTs. It also is necessary if you eventually want to run higher than the factory 14.7psi boost limit.

Glad you flushed your PS fluid ok. Sorry I did not find that link sooner.

 

[Postoy]

Nice work so far!

Id have a look at this boost controller

Docooler® 1-30 PSI Adjustable Manual Turbo Boost Controller Kit Turbocharger Boost Bleed Valve - Golden, Tables - Amazon Canada

I know its not fancy but its cheap and I am running the same one with no issue.

 

[AirheadNut]

I think the 'C' line probably is going to your boost gauge? It is not factory anyhow.... If it is the boost gauge, you could leave it connected there, or you could run it over to the intake manifold, and split off the line that goes to the boost sensor. This will give you a more accurate boost reading once you've intercooled the motor.

If you left the lines as they are, your boost controller would go in the 'B' line. The bottom of the boost controller (as per your pic) would go towards the 'C' or outlet nipple of the turbo. The side of the boost controller (as per your pic) will go towards the wastegate.

Don't run more than about 12psi without an intercooler. You might also consider getting a bleed off device to put in before your boost sensor. This would allow you to trick the computer into thinking the boost is lower than it is. This means less fuel which will mean cooler EGTs. It also is necessary if you eventually want to run higher than the factory 14.7psi boost limit.

Glad you flushed your PS fluid ok. Sorry I did not find that link sooner.

That is interesting. When I replaced my turbo, the new waste gate was set at 15-16 psi. I never fitted a bleed off valve to the boost sensor, and only once saw the overboost light come on. The highest temps I saw were around 930F post turbo. I never let stay over 875F for long. My boost line for the boost gauge teed in to the crossover pipe.

 

[GTSSportCoupe]

That is interesting. When I replaced my turbo, the new waste gate was set at 15-16 psi. I never fitted a bleed off valve to the boost sensor, and only once saw the overboost light come on. The highest temps I saw were around 930F post turbo. I never let stay over 875F for long. My boost line for the boost gauge teed in to the crossover pipe.

The light may only come on around 15-16psi, but I can tell you it starts cutting fuel before the light comes on. Sounds like your EGT's were under control. Mine would go up to 1200F post turbo when I first bought it (stock boost). Now it's a fight to get them over 800F.

 

[Lee777]

"its a fight to get them over 800F" ! Now thats a wet dream!

 

[Lee777]

Took the prado into the shop for rad fluid flush , tire rotation and balance. The mechanic asked me about the ehaust smoke when it starts. I explained its puffs smoke on cold starts but then gors away after 5-10 min when the engine warms up. He mentioned there was a disconnected and missing temperature guage which tells the computer how warm tge engine is. He also asked about the preheat sequence. I mentioned i turn the key to glow, the preheat light goes on for 5 seconds then goes out. About 5 seconds later i can hear the relay go click, and thats when i crank the engine. He said this missing sensor may be why there is smoke and a long cold start. Any ideas what he is talking about. I have new plugs on the way.

 

[GTSSportCoupe]

Took the prado into the shop for rad fluid flush , tire rotation and balance. The mechanic asked me about the ehaust smoke when it starts. I explained its puffs smoke on cold starts but then gors away after 5-10 min when the engine warms up. He mentioned there was a disconnected and missing temperature guage which tells the computer how warm tge engine is. He also asked about the preheat sequence. I mentioned i turn the key to glow, the preheat light goes on for 5 seconds then goes out. About 5 seconds later i can hear the relay go click, and thats when i crank the engine. He said this missing sensor may be why there is smoke and a long cold start. Any ideas what he is talking about. I have new plugs on the way.

The engine temperature sensor (that the computer reads to determine glow timing) is located underneath the intake manifold in the side of the block. Strange that yours would be disconnected. Just plug it back in?

After you hear the glow relay click off, you can turn the key back acc position, wait a second, then do a second glow sequence and start it. Might start easier and cleaner. I do this when the weather is colder if I want a clean start.

Does the engine miss when you cold start? Or is it smooth and just smokey? If it's smooth, it really should not be smoking that much. When you eventually remove the emissions stuff (throttle plates also), it might clear up that smoke problem.

 

[Lee777]

Cool. It takes a bit to start but once its warmed up its smooth. The temp sensor below the manifold is attached. He was probably talking about a plug that isnt connected, its hanging out of the loom at the thermostat where the water temp sensor is located. Its an xrra plug with no apparent place for it to attach. Maybe urs a factory plug thst is not being used?

 

[Lee777]

Cool. It takes a bit to start but once its warmed up its smooth. The temp sensor below the manifold is attached. He was probably talking about a plug that isnt connected, its hanging out of the loom at the thermostat where the water temp sensor is located. Its an xrra plug with no apparent place for it to attach. Maybe urs a factory plug thst is not being used?

 

[GTSSportCoupe]

I'm pretty sure that is for what appears to be called the "Water Temperature Switch" (I just checked the schematics for the Prado....). On my Prado, it plugs into a sensor that is located in the spot where you have something installed with a green wire attached to it. I'm not sure what the ECU uses this signal for to be honest. On other Toyotas it's used to turn on electric cooling fans at a certain temperature. I'll look into it more and let you know what I find. It could be another item that is different between the Surf and Prado engine? Or maybe someone just modified that engine....? Here is how mine looks:

 

[GTSSportCoupe]

Toyota Part number for the water temperature switch is: 89428-30090 . Doesn't seem to cross to any north american models....

 

[Lee777]

I'm pretty sure that is for what appears to be called the "Water Temperature Switch" (I just checked the schematics for the Prado....). On my Prado, it plugs into a sensor that is located in the spot where you have something installed with a green wire attached to it. I'm not sure what the ECU uses this signal for to be honest. On other Toyotas it's used to turn on electric cooling fans at a certain temperature. I'll look into it more and let you know what I find. It could be another item that is different between the Surf and Prado engine? Or maybe someone just modified that engine....? Here is how mine looks:

That engine is so clean you can eat off of it