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Help needed...VP motor on Ecotech ECU? It runs and drives but its not great :(

toyo truck

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Help needed...VP motor on VR ECU? It runs and drives but its not great :(

Hi Guys,

I have an RN106 4WD Hilux that I have recently converted to a VP 3.8L V6.
It runs and drives OK but I have a few niggling issues after the conversion
that I need someone with more experience tinkering with GM wiring/ECUs.

Thing is the truck is using HEAPS of fuel like 20L+/100kms
And it feels like its not making the right amount of power.
Also the gearbox changes are very odd.

Now the other night I was doing some investigation, and it looks like I'm running
a VP motor (series 2 I think from the newer coilpacks), on an VR ECU?? (bought it as a 'kit' :axe:)
On top of that, I'm 99% sure I'm running the electronic 4L60E auto box.

I've heard of people running an VR motor on a re-mapped VP ECU (808) but not the
other way round?

Could this be causing excess fuel consumption and strange driving characteristics?
How can the VP (with a MAP sensor) run on a VR ECU surely this would not be the most efficient?

Thanks guys, I've tried everything else this is my last hope and I'm going crazy trying
to fix it. Fuel consumption alone is insane!
 
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jonvaupel

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Hi, I am sure your problem is a mismatch between hardware and software. A VP V6 uses a multipoint fuel injection system where as the ECO tech uses a sequential fuel injection system, you can use a sequential injection ecu with a multipoint engine but your fuel consumption will be at least double if not more and your engine will run like it is overfuelling or even flooding, eg lots of black smoke under accelleration. The solution is to change your fuel injectors to the later sequential type same as what would have been used in the Eco v6.
Also if you are using an ECO v6 ECU you must use the ECO wiring harness and all the relative sensors eg the vp only uses 1 or 2 O2 sensors whereas the Eco motor uses 3, if you are using a 4L60E Trans the Eco ECU will work with this trans however if you have the incorrect harness on the engine and am using the VP Thottle Position Sensor, the ECU will be getting incorrect readings from the sensors and will incorrectly shift the trans accordingly. With the earlier mechanical trans TH700R you simply adjusted the shift cable to fix this problem but with the 4L60E there is no adjustments the trans is entirely controlled by the computer and the computer makes these decision entirely based on the information it is receiving for the sensors, so you can understand that if the wiring and sensors were incorrect or even no existent, the computer is trying to make decisions based on incorrect data.
Now finally when there is such a mismatch and the data the ECU receives is beyond the parameters permitted, the computer realizes there is something drastically wrong and puts the whole system into what is called Limp Home Mode basically this is the computer shutting down virtually all its systems and only keeping enough working so that you can drive your vehicle home or to the dealer, when a ECU goes into limp home mode it drastically richens up the fuel mixtures, shuts down all timing advances except for basic, and alter the shift changes to very basic so that you can limp the car home. My Guess is that this where your ECU is at, the best way to diagnose this is to borrow a comprehensive scan tool that can give you real time data, hook it up to the diagnostic port and run your engine and see if it goes into closed loop, if it remains in open loop as it will begin at startup your ECU is in LIMP HOME MODE and you need to investigate everything above and see why. Hope this helps.
 

toyo truck

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Hi mate,
Sorry for the delay of my reply, been flat out at work lately.

OK I have really done my research into this as I suspected the same thing!

Let me start with exactly what I have...
VP Motor (No CAM Angle Sensor, has a MAP not a MAF, has bracket for kick-down cable, but no cable as its a 4L60E.
4L60E Motor (Has large plug on side of box connected to loom, no kick-down cable)
VR ECU (States VR AUTO PCM on the ecu label)
VR LOOM (Wrecker markings on loom say "VR AUTO")

So basically I am running a VP engine off a VR ECU and Loom!!
(I am presuming it is an early VR V6 which was not ecotech, but still used a 4L60E and CAM Angle Sensor aswell as non batch fire injection and a MAP sensor not MAF).

So this may well be the cause of my issues mate. Its definately running a VP throttle position sensor so you might be right about the
ecu trying to incorrectly shift the box based on bad data from sensors.

I do not have a scan-tool, but I pulled the ECU flashing codes and got
44 - Exhaust Lean (dunno why this is if it is overfuelling - I notice a little black smoke on idle when 4WDing up steep inclines?
and
48 - CAM Angle Sensor Missing. (this is due to the VR loom having a connector but no sensor to plug into it and ECU realises its missing).

My auto box shifts all the way up from 1st -2nd -3rd - 4th and back down again so it can't be in limp hom mode as you only get 3rd and manually
shift to 2nd right? (No 1st and no Overdrive).

So maybe its the mismatch in sensors thats causing grief?

At any rate, I am going to hook up a diagnostic scan tool and grab the data off the ECU. I'll let you know what it shows.
This will tell me almost definately what is the problem. The motor mechanically works fine, as does the 4L60E, its just not driving the way
I would like, very underpowered for a commo v6 and not very responsive. so its gotta be an ECU/Timing thing.
I've heard that VP motors run a different fuel map and timing to the VR motors so if I am running on a VR ECU this is what I will be running.


cheers guys,
Bart
 

Not_An_Abba_Fan

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Firstly, don't take any notice of what jonvaupel says, as you have a VR ECU which is still the Buick. The Ecotec came out in the VS not the VR so everything he said is irelevent.

Your issue would most likely be due to the VP having no cam sensor. You can get it switched off though through a memcal tune.

The code 44 may be a vacuum leak.
 

toyo truck

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Hey "not an abba fan". Me either ;)

In all fairness to jonvaupel the title was originally ECOTECH as I thought all VRs were ECOTECH until I did a heap of
research to confirm this. I thought the last models of VR were running the ecotech? but either way it does not apply now that I have
confirmed I am running a VP motor, on a VR ECU and VR auto loom.

Yes I have no Cam Angle Sensor, and yes I could get it removed from the ECU, or I could fit a CAM Angle Sensor to my motor with the magnet p/u.
Problem is this will only give me sequential injection right (Seq injection is controlled by the cam angle sensor. Without this sensor ECU will revert
back to batch injection).
I will still be stuck running the VP motor on a VR fuel Map and Timing, which is just not going to work all that well given the difference between
the VR and VN/VP motors. And running baatch injection on a ECU designed to run sequential will be wasting a heap of juice I rekon.

My options as I see them are
1) Run a VP fuel map and timing bin on the VR ECU, but retain the 4L60E control. - Easiest option by far
2) Swap to a TH700, and a VP/VN ECU and VP/VN Loom - The "proper" way of fixing this issue but $$$ and lots o effort.
3) Swap to a VP/VN ECU and VP/VN Loom and fit an Toyota 4WD R151 5 speed manual behind the commodore v6. - very expensive.

So I am currently making up some stuff to log the data from my ECU so I can see exactly what the issues are from the ECU perspective.
Will be very interesting indeed to see whats happening.
 

Not_An_Abba_Fan

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If it is injecting too much fuel you shouldn't be getting the code 44.

The VR doesn't have sequential injection, it has batch injection, that is, it fires the injectors in groups of two. The VN/VP fired all injectors at the same time. Not having a cam sensor shouldn't make that much difference though.

A cam sensor will make it run a bit leaner as there are less injectors firing. The fact that yours blows black smoke indicates rich running not lean.

Is the coolant temp sensor OK? Not the sender for the gauge, but the sensor for the ECU.

Also, do you have your intake air temp sensor in the intake pipe?
 

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Try Downgrading the ecu as seeing the engine isn't ecotec
 

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Neither is the ECU....
 

toyo truck

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Thanks for your reply mate,

OK definately pulling 44 code on the ECU. Like ALL the time. Have cleared it by removing fuse, comes back as soon as I accellerate moderately.
I know what your saying though, how's it running lean with too much fuel??
Thing is I definately get black smoke on idle and it smells very much like fuel in the engine bay and outside it. Exhaust smells very rich?

So I'm not sure why this is, maybe the ECU is completely confused by what it is seeing?
Sorry I got mixed up with the batch vs sequential on ecotech.
So I thought that the batch injection was controlled by the cam angle sensor? IE tells the motor which cylinder is about to fire/exhaust.
without the Cam angle sensor, and the magnet pickup on the cam, I'm guessing that it won't be doing batch injection as the ECU won't know
exactly when to fire the injectors.

So I could fit the Cam sensor, and that will use less fuel right, but I'd still be running the VP motor on the VR tune.
VPs require more timing and a different fuel map to a VR right? This could be causing me grief bigtime

I beleive the coolant temp sensor is fine. Thermos kick in and out as needed, no code on the ECU for this? Guage also works fine.
I'm guessing the ECU controls the thermos based on this sensor? so yeah should be fine if this is the case.

I'm not so sure about the intake air temp sensor in the intake pipe? I have no sensors anywhere on my intake pipe. Just my POD filter,
into some alloy piping at a 90 round bend and straight into the throttle body. Where is it usually located? What would it mean if I did not
have one of these? Wouldn't the ECU register a code saying something regarding intake temps?
 

Not_An_Abba_Fan

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The IAT is at the rear of the intake on the drivers side (I think).

Could be a faulty O2 sensor telling the ECU it is lean so it is throwing more fuel in.

Have you checked for vacuum leaks?

The cam sensor tells which injectors to fire, yes, but without it, it defaults back to the same injection method the VP uses anyway.

I would get a memcal tuned to run the electronic auto and VP tune. Cheapest and easiest option. Get hold of the1 or Delcowizzard on here, they will sort you out.
 
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