Project Supracharger

[Chris Wilson]

You can perhaps see 12 volts at the injector feed, but how does it look if you load it up and try and draw current? Say one amp? 12 volts into 12 ohms will draw an amp. You would need a hefty wire wound resistor, say a 25 watt one, or if less wattage, only do the test for a very short time. Measure the voltage after the resistor, to ground. then try the same test on another injector feed and compare. A 12 ohm resistor is a none preferred value, so go for a 10 ohm, say from here:

 

http://www.ebay.co.uk/itm/Arcol-25W-Aluminium-Clad-Wirewound-Resistor-Range-0R1-to-10K-Ohms-ROHS-/251420421856?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item3a89d32ee0

 

Breconjess is a good ebayer. A 10 ohm will draw 1.2 amps.

[David P]

Thanks for the input Chris, I have stopped making my brain ache and gone for a "pint".

 

Shane has rustled up a set of 10 Ohm jobbies, when the postman remembers what he should be doing for a living.

 

In the mean time, I'm going to fit a set of new clips and link all 6 positive wires close to the injectors which will remove beyond any doubt what has already checked out more times than I've changed my socks.

Edited May 9, 2014 by David P (see edit history)

[Chris Wilson]

I am not saying my idea is likely to give an answer, just that a no load voltage measurement can be confusing, 12 volts at a few milliamps or microamps that a digital or analogue meter may draw is very different to the voltage under the real circuit load Good luck, it must be something simple, but as you know, the simple answers can be hard to find, in the grand scale of electrickery

[David P]

I've fitted new clips and linked the live circuit at the pig-tail joins, for no change.

 

The first video is a cold start with injector driver plugged in and ICV unplugged, running on 5 injectors and is a good demo of how uneven running chatters the supercharger and gets ones ear into the rhythm of what sounds to be 5 2/3rds cylinders in the second and warm engine clip running with resistors.

 

I've just about given up with old money diagnostics and hope that Shane can nail it with a shiny Oscilloscope.

 

 

With injector driver.

 

 

 

With Maplin ceramic 6.8 Ohm 10W resistors.

 

[Shane]

I've fitted new clips and linked the live circuit at the pig-tail joins, for no change.

 

The first video is a cold start with injector driver plugged in and ICV unplugged, running on 5 injectors and is a good demo of how uneven running chatters the supercharger and gets ones ear into the rhythm of what sounds to be 5 2/3rds cylinders in the second and warm engine clip running with resistors.

 

I've just about given up with old money diagnostics and hope that Shane can nail it with a shiny Oscilloscope.

 

 

With injector driver.

 

 

 

With Maplin ceramic 6.8 Ohm 10W resistors.

 

 

Well the twin channel scope will be here in a day or so and we can take another look, being twin channel is good as we can compare cyl 5 with the others.

 

But, you know its a fuel fault, its not the injectors, its not the wiring either on the output side of the P&H module to the injectors, neither is it a wiring fault to the module, the fuel rail has fuel at the correct pressure, the injectors all have the same 12v constant feed and you are confident after swapping channels on the aem injector driver that it is not that, it only leaves the ecu I am afraid. I am still concerned until someone can tell me otherwise, about the load you have been running on the injector driver stages of the ECU using only a 6.8 in series with the low impedance injectors.

 

One other thing did occur to me, you had both sets of injectors looked at by Dan and he came up with a matched set, could it be that the original No.5 is now the current No.5?

 

I fear that No5 injector driver has cooked within the AEM ecu and is putting out something the AEM P&H driver is not happy with. Scope or no scope I cant see what else it can be now. You have eliminated everything else from the equation already now.

Edited May 15, 2014 by Shane (see edit history)

[mellonman]

To confirm the ecu fault David, Can you not swap the the injector chanel on the ecu ? or is it just a 6 chanel ecu ?

if its just a 6 chanel ecu you could always still prove it by swapping say 5 and 6 injector inputs and see if the fault moves to injector 6

[Shane]

To confirm the ecu fault David, Can you not swap the the injector chanel on the ecu ? or is it just a 6 chanel ecu ?

if its just a 6 chanel ecu you could always still prove it by swapping say 5 and 6 injector inputs and see if the fault moves to injector 6

 

I am not that up on AEM ecus but am sure david said it supports ten channels, as does the standalone peak and hold driver. Not sure you could prove it by swapping 5&6 though unless you can also tell the ECU that you have done that, or the injectors will be fired at the wrong time.

[mellonman]

I am not that up on AEM ecus but am sure david said it supports ten channels, as does the standalone peak and hold driver. Not sure you could prove it by swapping 5&6 though unless you can also tell the ECU that you have done that, or the injectors will be fired at the wrong time.

 

im not 100% on how the stand alone ecu is wired in compaired to the piggy back i have , but would it not be very simple as to swap wiring from say injector 5 channel to injector 10 channel and then set it as that in the ecu software ? ie 1,2,3,4,10,6 but like a say i dont know what the software is like on the standalone

 

with my piggy its even more simple as its just swap the wires and its done as the ecu see that the 5 channel is no longer used and 10 is and copies accordingly , just an idea as thats what some have done with some fic's that have had a channel go on them

[Shane]

im not 100% on how the stand alone ecu is wired in compaired to the piggy back i have , but would it not be very simple as to swap wiring from say injector 5 channel to injector 10 channel and then set it as that in the ecu software ? ie 1,2,3,4,10,6 but like a say i dont know what the software is like on the standalone

 

with my piggy its even more simple as its just swap the wires and its done as the ecu see that the 5 channel is no longer used and 10 is and copies accordingly , just an idea as thats what some have done with some fic's that have had a channel go on them

 

I think I see what you are saying now, and that's been done much earlier on. We have tried channel 7 and channel 10 of the AEM peak and hold injector driver (which is a bit like yours as in its a piggy back uunit for the AEM ECU) in place of channel 5 and its still the same. But to try another channel of the actual AEM ecu is not that easy, not to me anyhow as I have no idea how to programme the ecu to tell it to use an alternative driver, don't forget the AEM is a standalone ecu.

[David P]

I'm now suspecting the ECU, which doesn't have spare channels as I thought it might.

 

Should the Oscilloscope confirm it's the ECU, it'll have to go back to USA for inspection and repair.

[mellonman]

there are many companies in the uk that could repair this , but it maybe a good time to get a ecu thats more upto date

[David P]

Today was Oscilloscope Day.

 

Now there's visual confirmation of what we already knew, 5 cylinders with the injector driver and 5 2/3rd with the resistor pack.

 

The poor signal on no. 5 partially functions the injector via the resistor pack yet the i-driver doesn't like it and won't fire the injector at all.

 

I plan to scrutinise the ground circuits for no. 5 injector and i-driver before I blame it on the ECU and Shane has kindly loaned me his shiny new Oscilloscope to confirm either way. Thank you.

 

[video=youtube_share;6-MtDV45vtE]

 

Edited May 26, 2014 by David P (see edit history)

[Chris Wilson]

Have you a means of accurately checking the coil resistances of number 5 injector and the others? Most multi meters are not very accurate at low resistances unless you have the ability to null out test lead resistance. Have you swapped number 5 injector with one that triggers OK? Did the issue follow the injector or stay with the ecu channel? I am having similar issues with the thyristor driver of my TIG welder that went pop the other week. If you have a low amperage current clamp `scope the current patterns for number 5 and some good ones.

[David P]

No. 5 injector has been changed and it fires fine on test, the problem is with the channel, that why I'm going back to that circuit.

I haven't opened and inspected the earth connection for no. 5 pigtail and want to rule that out.

[Chris Wilson]

The injector driver transistors may be discrete devices and easy to change. It may be kitchen table repairable. I don't suppose they give you a schematic?

[David P]

I don't suspect the injector driver, if that earth checks out okay then it can only be the ECU at fault.

[Shane]

I don't suspect the injector driver, if that earth checks out okay then it can only be the ECU at fault.

 

Chris means the injector driver transistors in the AEM ecu I think, and this is something you may want to consider we do prior to sending it back to AEM?

[Chris Wilson]

Yes, that's what i am on about, being fairly high power they may be easily accessible on the chassis and use conventional mounting techniques. I have a very good vacuum de-soldering station, but the usual disclaimers apply

[David P]

Thank you for the offer Chris, I'll see what I can find out.

[David P]

I've had an ebay search running for around a year for a "Toyota 7M-GTE CPS 19300-42010" without success.

 

Last week, my sarcasm goaded me into searching in Fwit mode and I found two of them in a matter of minutes, one under "1930042010" in the Classifieds and the other under "supra engine part" in an Auction.

 

I like having spare components so bought them both and in between buying one and bidding for the other, my original search flagged up another one in real money.

 

These things are worse than double-decker busses.

 

The pic shows the space it will free up, yet not until after the present Electro Gremlin has been sorted.

 

Edited May 27, 2014 by David P (see edit history)

[David P]

Update:

 

Since making and emailing the oscilloscope recordings as requested by Dan Turner and shown in post 1812.

 

Despite telephoning AME weekly and leaving a message with staff to remind that my email remains unanswered, no answer has been received.

 

To get to the bottom of this matter, I have removed the ECU and sent it to AEM USA for a full diagnostic.

 

Yes I am very disappointed with this disgraceful service and no I don't want my build thread turned into a slagging page.

 

Thank you.

Edited July 14, 2014 by David P (see edit history)

[David P]

Double post.

[Shane]

I hope you gave AEM some pointers and the history?

 

Sorry I haven't been in touch, was mega busy at work and now in RO

[David P]

Even our home videos.

 

Give Borat a wedgie from me.

[mellonman]

Any news from aem dave? I doubt not as the lack of update but I thought I would ask , have you thought about another ecu?