1993 VAF to MAF conversion & Turbo

[Jimjim]

My aim with this conversion is to better improve the metering of the air volume going into the engine and to stop the tendency for the VAF unit leaning the AFR at high RPM.
The reason I want to fix this AFR at high RPM is I plan to install a turbo setup. There are many options out there where you can add a piggy back computer and a extra injector. To me this does not solve the problem it just masks the problem. And it poor's more fuel in. I still want the truck to be as economical as possible as they love to suck the gas anyway so no point throwing more in. And you are paying around $1000NZD for these piggy backs. Might as well go new aftermarket computer.
I brought 2 of these converters in April 2015. They aren't a huge price tag so another reason I decided to purchase. If it wasn't meant to be it wouldn't be a huge loss.
Its taken me basically up to now (4 weeks ago), to actually get one installed and map it all.
Now speaking English and Pin the manufacture speaking Russian, communication was bound to be a little difficult. But Pin has been absolutely fantastic. I've got strings of emails here backwards and forwards, he converted all the software to English, all the wiring info, and how to actually use the software as I had no idea. I'm still only scrapping the surface of what this software and converter can do.
The below is not how Pin is going to tell you how to do it, but I like to jump the gun and once i'm in doing something i'll carry on until I figure it out even if I don't get the same out come the conventional way.

This is a list of what parts I used for the conversion
Removed VAF P/N:22250-66020
Installed MAF P/N:22250-66050
Toyota connector P/N:90980-11317
Toyota pins P/N:82998-12440
AEM wideband O2

I have had the AEM wideband O2 installed for quite sometime as I wanted to prove to myself that the VAF was causing lean and uncontrolled conditions, so I have a good idea what AFR the engine normally operates at, it is normally on the richer side down low 12-13:1
The MAF I installed was off the latter model 1997 80 series land cruiser when they changed the computer system from OBD1 to OBDII. I went with this meter as I know it is already sized for this engine, it has a THA output (IAT sensor) so no having to sort something else out there. This MAF was a little harder to source but I think it was the right descion. There is the Landtank MAF housing out there and I was keen to go for it but the cost put me off if this wasn't going to work.
The only issue I came across was the VAF has a switch in it for the fuel pump relay. Pin has now sorted me out how to control this now. Will put this information up as I go through this writeup.

I couldn't figure out how to get the software to do an initial map of the old VAF. So I pulled it out and installed the MAF, jumped the 2 fuel relay pins so the fuel pump is always running at the moment.
It took a bit to get started as I had no idea what I was doing, I would crank and the O2 would give me a brief AFR so I would move the graph a bit unit I got it running very lumpy and really rich. I knew the VAF had an output oppersite to the new MAF, so I clicked invert box and then turned on the auto correction. This lets the engine run a lot better. And from here I started to build my mapping table. You can see from the photo's how it developed. this really average looking table was all done with the truck stationary through different RPM's. This table was rubbish on the road though, with flat spots, lean rich, engine stuttering etc. The final table I have made runs the truck perfect now.

 

[Jimjim]

Photo's of the first stage install the initial tune that was very rough.
Graph also of the finish tune for now, will continue once the turbo is installed.

 

[Jimjim]

Pin the creator also looked at my data logs, I have some interference issues that I need to fix up before I do anymore running. I'm using shielded wiring so will earth all the shields. Moving all the power sources and grounds as close to the ECU he has also advised.

His comments here:
If you zoom in and then will try to move through your log( right mouse button+ dragging to loft or right) you will see a lot of spikes.
This is not good.
The problems causes this spikes could be:
1. Wrong power supply ground point for the converter , airflow meter and WBOS controller.
The better way is to take supply ground for all of this devices from one point which is one of the ECU mounting bolt .

2. Ignition Noises. Please check the highvoltage ignition cables at night for lighting or sparking. If you will see lighting or sparking on the surface of this cables, they need to be replaced with new.
Also check all spark plugs( also a gap between electrodes of each)
If any spark plug has a too big gap between electrodes it may causes misfires and as a result of this the noises which we can see in the log.

 

[Jimjim]

The wiring pin outs I used. I could never find the pin out for the MAF airflow meter in any of the Manuals. I think I ended up finding it on the original, VAF to MAF conversion forum on here.

 

[Jimjim]

You will notice in the diagrams that the VAF has a built in fuel pump switch so that when the flapper first moves open on the initial crank of the engine the fuel pump is told to start running.
The MAF does not have this feature, so I asked for Pin help here. Attached is what he said most of the guys run that he knows of.
It's just running off the coil.
I've attached both the original and my drawing. I have modded slightly as I just want the relay to connect and disconnect the original 2 wires for my pump. so no real load being carried by the relay.

 

[Jimjim]

This is as far as I have got so far. Turbo is currently being installed, in spare time. And I need to build the circuit board above. Have got all the components ordered.

I always mount the oil feed off a flexi line as if that small line breaks its all over pretty quickly. I learnt this from someone else when I was building my jet boat.

As you can see my filter box is reasonably modified, 4 inch stainless steel 45degree bend chopped and welded to a tight 90degree then heated and squashed to fit the lid nut back on and to fit under the bonnet.

Everything will be excessively wrapped to titanium lava rock weave heat wrap. That stuff is amazing. I don't even bother about the old white wrap anymore, this new stuff can handle twice the heat continuous.

Water to air intercooler setup is already installed, water to airs are more effecent than air to airs in my option and can fit them in tighter spaces. The radiator for this system is mounted with 10" fan on seperate temp controller. I found these temp controllers that have a good range of adjustability, not 100% if they will work yet but for $3 each can't go wrong.

Also running an oil cooler, thermostat controlled sandwich plate under the oil filter.

And running seperate cooler for the automatic trans, wanted to get the trans oil out of the main radiator to help prevent heat build up in the cooling system.

Both the Oil cooler and trans cooler share another 10" fan, this will also be on its own temp controller

 

[Jimjim]

Few more images for the above

 

[Jimjim]

Time for an update.

The Fuel pump switch diagrams I put above, didn't work. Well I couldn't get it working. Talked to a friend and he threw it in the bin for me and programmed up an Andruno. Full logically controlled fuel pump switching I have now. Don't ask me about this as all I know is it works great.

All wiring has been tidied up and finished, all shields connected to ground.

I moved my power pickups to run from the ECU power but found that the interference was terrible the VAF to MAF converter struggled to run it was so bad. So moved them back to where I originally had them and with the shields grounded interference was low.

I still have the Temperature controllers to hook up to the electric fans. will get around to this at some stage.

A full 3" Stainless Steel mandrel exhaust was made up. Only took me a couple days. Really happy with the result. It has V band flanges every 900mm ish so the exhaust just all clips together making it really easy to install and removed if you just need to work in one area. Also made it easy to mock up and purge tig weld being in smaller lengths. Its running 2 Adrenaline R mufflers which keep it quite but also let it breath.

The rest of the Turbo install went pretty well. Oil return was put into the sump pan. Removed welded and reinstalled. Water feeds and returns plumbed in. I used the existing lines left over from removing the EGR valve for memory.
One Issue I had with the turbo, I was told by the supplier that they were running 5psi. So in my excitement I installed the turbo without checking the wastegate actuator opening pressure. Turns out it was set at 12-13psi. The truck did go mighty well when I took it for a spin. but at that pressure things wouldn't last long and it was running out of fuelling. So had to pull the turbo all back out again as couldn't get to the actuator. Cut the actuator open and played around with different springs. It is not set for cracking pressure of around 2.5psi and gate full open at 6psi. Right around where I wanted it.

Will put some more up later when I get a moment

 

[landtank]

WOW that is really good. I feel you are going to have issues once the turbo setup is running with a very lean condition once you exceed the stock motors air flow volume.

Do you know what the output voltage is during WOT?

 

[PabloVTA]

any news on this build?

 

[Petem226]

Hi, wondering how you went with setting up the pilot? I was looking to do the same but without the turbo

 

[Jimjim]

WOW that is really good. I feel you are going to have issues once the turbo setup is running with a very lean condition once you exceed the stock motors air flow volume.

Do you know what the output voltage is during WOT?

Yes I did have some issues running lean from about 3800RPM onwards. I've fixed that though.
I'll have to look into the voltage next time I have the laptop plugged in.

 

[Jimjim]

Time for a bit of an update.

I'll start with saying every project has its issues but that is why it is a project.

The previous owner never ran glycol (anti-freeze / anti-boil) in the radiator. So one of the head gasket steel rings around one of the cylinders let go and showing as over heating. And it took me along time to get the cooling system clean.
I would assume that the turbo made this show more quickly, had maybe done 100km with the turbo installed.
So pulled the head off, had it cracked checked and checked for straightness, valves checked for leakage. For an engine that had done 330000km, none of the valves had any leakage, no cracks and perfectly straight.
So a new head gasket and it was back together.

About 18months ago finished all the modifications that required re certification here in New Zealand and had it certified.

Since having it on the road and doing a few thousand km's. And fiddling getting the Pilot converter and air/fuel ratios to where I wanted them.
The issues I have come across.

Dash lights:
Catilac converter over heat light
This is always still on at the moment, as I removed the Cat when putting the new exhaust through. Pilot does offer a piggy back to correct this. I will do this when I get around to it one day. Doesn't effect the drivability at all.

Engine check lights
The initial code was for the 2 factory O2 sensors, they didn't like being installed into the new exhaust system. Replaced the O2 sensors. fixed that code.
The next code I got after fixing the first code is now to do with the VAF. I'm assuming this is to do with the VAF to MAF swap and there might be a signal that is out of tolerance. I haven't bothered looking into this code at all, maybe one day. It doesn't effect the operation of the engine at all.

From about 3800RPM running lean, no matter how I adjusted the Pilot converter I could get anymore fuel in:
The problem, the factory injectors had run out of duration, couldn't flow any more fuel
The fix, installed some larger direct fit injectors 600cc, re maping of the Pilot converter to regain the correct air / fuel ratio's at all RPM's

From about 4000RPM felt like hitting a fuel cut and running lean, again couldn't adjust the converter to get anymore fuel in:
The Problem: Installed a fuel pressure gauge and found as well as previously loosing injector capacity. The fuel pump wasn't keeping up the pressure.
The fix: Installed a Bosch 023 intank fuel pump.
Fuel delivery is now no longer an issue, big flow, constant pressure right up to max flow, which hopefully I will never use.

Spent some time replotting the Pilot converter to overcome the big injectors and fuel pump as now they poor in a lot more fuel than my previous settings.
I can now hold WOT on 6 psi up to the limiter running 12.5:1 air / fuel ratio. I can make the air / fuel ratio as lean or as rich as I want.

I think I am now at the limit of the factory computer with ignition timing etc, but i'm pretty happy with how it is running. The fuel economy has remained about the same if you drive it the same as prior to having the turbo, reasonably conservitively about 17L per 100km.

But since having the turbo, naturally you drive it a little more to it's new ability. Almost any hill on the open road it is no problems what so ever to stay at 100km/h even if you've got 2 ton on the trailer behind no need to slow down for any hill. But I do frequently have a fuel consumption of around 20L per 100km. So the 85L factory fuel tank doesn't last long nether does my bank account when filling it up. I mainly only use it for towing anyway, which I what I built it for.
As you can see the Pilot converter VAF to MAF conversion seems to have done its job quite well, considering the amount of other modifications that have been made.
I'm sure I have missed some bits and I haven't been great of taking photo's of progress.

 

[Jgrauman]

Time for an update.

The Fuel pump switch diagrams I put above, didn't work. Well I couldn't get it working. Talked to a friend and he threw it in the bin for me and programmed up an Andruno. Full logically controlled fuel pump switching I have now. Don't ask me about this as all I know is it works great.

All wiring has been tidied up and finished, all shields connected to ground.

I moved my power pickups to run from the ECU power but found that the interference was terrible the VAF to MAF converter struggled to run it was so bad. So moved them back to where I originally had them and with the shields grounded interference was low.

I still have the Temperature controllers to hook up to the electric fans. will get around to this at some stage.

A full 3" Stainless Steel mandrel exhaust was made up. Only took me a couple days. Really happy with the result. It has V band flanges every 900mm ish so the exhaust just all clips together making it really easy to install and removed if you just need to work in one area. Also made it easy to mock up and purge tig weld being in smaller lengths. Its running 2 Adrenaline R mufflers which keep it quite but also let it breath.

The rest of the Turbo install went pretty well. Oil return was put into the sump pan. Removed welded and reinstalled. Water feeds and returns plumbed in. I used the existing lines left over from removing the EGR valve for memory.
One Issue I had with the turbo, I was told by the supplier that they were running 5psi. So in my excitement I installed the turbo without checking the wastegate actuator opening pressure. Turns out it was set at 12-13psi. The truck did go mighty well when I took it for a spin. but at that pressure things wouldn't last long and it was running out of fuelling. So had to pull the turbo all back out again as couldn't get to the actuator. Cut the actuator open and played around with different springs. It is not set for cracking pressure of around 2.5psi and gate full open at 6psi. Right around where I wanted it.

Will put some more up later when I get a moment

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Love this exhaust very nice.

 

[bigredmachine]

I saw that you were running a different oil cooler, are you still running the stock oil cooler or did you bypass it? and if you bypassed it how did you do it

 

[landtank]

Very nice.i like to see yhe diagnostics prior to onstalling components.

 

[Jimjim]

I saw that you were running a different oil cooler, are you still running the stock oil cooler or did you bypass it? and if you bypassed it how did you do it

Hi, a factory engine oil cooler are you talking? As far as I can see there isn't one. I used a sandwich plate under the oil filter with an inbuilt thermostat, so just remote oil cooler from there.
The automatic transmission oil cooler from factory is in the bottom of the radiator. I just pulled these lines off and extended them to the new larger external cooler, so now the transmission requires a little more oil to fill.
There is a factory power steering fluid cooler, if you can can call it that, just a bit of bare steel pipe.

 

[scottryana]

The factory oil cooler is built into the block, it is an oil/coolant cooler. Oddly it is under the exhaust manifold.

Hi, a factory engine oil cooler are you talking? As far as I can see there isn't one. I used a sandwich plate under the oil filter with an inbuilt thermostat, so just remote oil cooler from there.
The automatic transmission oil cooler from factory is in the bottom of the radiator. I just pulled these lines off and extended them to the new larger external cooler, so now the transmission requires a little more oil to fill.
There is a factory power steering fluid cooler, if you can can call it that, just a bit of bare steel pipe.

 

[bigredmachine]

Hi, a factory engine oil cooler are you talking?

yes, under the exhaust manifolds as scott mentioned above.

 

[fjbj40]

My aim with this conversion is to better improve the metering of the air volume going into the engine and to stop the tendency for the VAF unit leaning the AFR at high RPM.
The reason I want to fix this AFR at high RPM is I plan to install a turbo setup. There are many options out there where you can add a piggy back computer and a extra injector. To me this does not solve the problem it just masks the problem. And it poor's more fuel in. I still want the truck to be as economical as possible as they love to suck the gas anyway so no point throwing more in. And you are paying around $1000NZD for these piggy backs. Might as well go new aftermarket computer.
I brought 2 of these converters in April 2015. They aren't a huge price tag so another reason I decided to purchase. If it wasn't meant to be it wouldn't be a huge loss.
Its taken me basically up to now (4 weeks ago), to actually get one installed and map it all.
Now speaking English and Pin the manufacture speaking Russian, communication was bound to be a little difficult. But Pin has been absolutely fantastic. I've got strings of emails here backwards and forwards, he converted all the software to English, all the wiring info, and how to actually use the software as I had no idea. I'm still only scrapping the surface of what this software and converter can do.
The below is not how Pin is going to tell you how to do it, but I like to jump the gun and once i'm in doing something i'll carry on until I figure it out even if I don't get the same out come the conventional way.

This is a list of what parts I used for the conversion
Removed VAF P/N:22250-66020
Installed MAF P/N:22250-66050
Toyota connector P/N:90980-11317
Toyota pins P/N:82998-12440
AEM wideband O2

I have had the AEM wideband O2 installed for quite sometime as I wanted to prove to myself that the VAF was causing lean and uncontrolled conditions, so I have a good idea what AFR the engine normally operates at, it is normally on the richer side down low 12-13:1
The MAF I installed was off the latter model 1997 80 series land cruiser when they changed the computer system from OBD1 to OBDII. I went with this meter as I know it is already sized for this engine, it has a THA output (IAT sensor) so no having to sort something else out there. This MAF was a little harder to source but I think it was the right descion. There is the Landtank MAF housing out there and I was keen to go for it but the cost put me off if this wasn't going to work.
The only issue I came across was the VAF has a switch in it for the fuel pump relay. Pin has now sorted me out how to control this now. Will put this information up as I go through this writeup.

I couldn't figure out how to get the software to do an initial map of the old VAF. So I pulled it out and installed the MAF, jumped the 2 fuel relay pins so the fuel pump is always running at the moment.
It took a bit to get started as I had no idea what I was doing, I would crank and the O2 would give me a brief AFR so I would move the graph a bit unit I got it running very lumpy and really rich. I knew the VAF had an output oppersite to the new MAF, so I clicked invert box and then turned on the auto correction. This lets the engine run a lot better. And from here I started to build my mapping table. You can see from the photo's how it developed. this really average looking table was all done with the truck stationary through different RPM's. This table was rubbish on the road though, with flat spots, lean rich, engine stuttering etc. The final table I have made runs the truck perfect now.

Thread revival

How is the conversion doing, if you still have it?