Qpeng help

Guys,

Purchased a used mbe992, sent it to Ben and had it tested and recalibrated for my engine/turbo combination and have been making a loom for the past couple of months using mainly a few links from this site and a pinout provided by qpeng. Went for a first start yesterday but having a few issues.

ECU seems to power up fine, primes the pump and all my relays are coming to life. During cranking the fuel pumps run fine also.

My injectors are not firing, neither are the coilpacks. I have run them through my power up relay, via individual fuses( none blown), my fuel pumps, n75 and lamba heat through another relay, individually fused(none blown)

Tested power at the coil and inj pin 1 and i have 12v. Map ecu signal reads 1.66v atmospheric and linear up and down with vac and press applied to 0v and 5v respectively. Crank sensor 830 ohms resistance. Ait 5v accross when ecu powered, ECT for the ECU 5v ( have substituted with a mk3 temp sender and plug to run my mk1 clocks.)

Just looking for some direction really as to why the ECU would not switch the injectors and coils, if its missing a signal. If i unplug the crank sensor and try to start the engine it stops the fuel pump working during cranking so its seeing something from it.

Must add its an AGU which i ran fine for 6 months on a converted me 3.8, the only components i have changed for the qpeng are to 4 pin coil packs and AUM injectors. ( plus a k03s)

Hope you guys can shed some light for me, am going to have to get hold of a CAN adapter when funds allow but until then keep fault finding.


Cheers

Adam

 

What car is the lump going in?

Earthed the coils properly?

Double check your pin outs on the ECU too as it is easy to mix them up.

 

Checked the 2 coil earths and both are good, double checked the ECU earth also.

Rung out most of the pinout but will double check it this evening, although went over it so many times when building the loom as its my first one.

Its going in a mk1 golf.

The only thought i had in the middle of the night was about the coil trigger loop. The injectors are switched earth but have wired the coils up as switched positive as per OEM. ( positive signal from ecu and 2 earths to coil pack) nothing on the pinout to suggest this is right or wrong.

Cheers

Adam

 

^^ The OP said the ECU was set up for amplified coil packs and, from my experience with the same, would have had new bespoke QPEng software uploaded and a base calibration to run AUM type injectors.

Ben is pretty spot on with things like that.

Does not explain the comment 'injectors are not firing', which could be to do with installation.

 

Cheers for the reply guys.

Yes the ECU is set up for AUM type coil packs, although i have gone for the bolt down type 4 pin coil packs to enable me to retain my cam cover. Assuming there is no pinout difference between the 2.

Have rung out the ECU triggers for cylinders 1 to 4 and they are correct as per the pinout Ben supplied and 12v is present at pin 1 of the injector.

Just seems weird that both coil packs and injectors aren't actuating????

Think im going to have to wait until i can afford the CAN adapter to read the ECU. ????


Cheers

 

I would suggest doing that as well as asking Ben to send you the definition file for the MBE992.

 

You have ditched the Ignition amplifier haven't you?

And where did you take your permanent live from? Maybe worth eliminating the relay.

I also think AUM and AGU coils fire in a different way. The AGU requires a negative signal to fire. Sure someone can clarify if they are interchangeable

Also I remember when doing mine the instructions for the wiring on throttle position sensor plug was confusing. I got it wrong to start with and got no spark etc then switched it over and all was good. Need to reverse the 5v and ground sensor pins in the plug

 

Hi,

Yeah the amplifier is gone, used an AUM loom to make the loom, stripped it down and rewired.

Do you have any more info on the throttle plug please? Got earth on 4, 5v on 5 and signal on 7.

Could be a lead...........

Cheers everyone so far..

 

On an AGU harness so should be the same pins but I am not sure what colour wires AUM uses:

5v (purple/red) to 4

Ground (brown blue) should go to 7.

Signal should be 5 regardless of which way round you have others.

Ask Ben to clarify

 

Hi,

Cgecked with Ben today and the way i have it is correct. Depends on wire colours apparently but should always be pin 4 ground.

So had another little play and my voltage is dropping to 10v during cranking accross the ECU , coils and injectors. Should the injectors and coils be able to fire at this lower voltage during starting? The engine is turning over fine and not labouring.

Cheers

Adam

 

I wire the injector supply from the output of the fuel pump usually and the coil packs supply KL15 ( ignition live).

 

Cheers, i have 2 40a relays running direct from a bus bar ive installed as ive relocated the battery in the boot using 00 gauge cable. Relay 1 is ECU, injector and coil power, relay 2 is n75 power, lambda heat power and fuel pumps.

Got the afternoon off work so going to ring out all my pins again and treble check everything.

Thanks for the suggestions so far!

Adam

 

Sorted it!!!!!

Had a double check through my wiring, when i bought the AUM loom to convert the CPS plug was missing, i pinned it up from a picture on the net and did the other end by colour, mixed the pins up in the plug!! Started first crank :-)

Got some tidying up of the routing of the loom and bolt the ECU in then i can start to play with the map a bit.

Thanks for everyones help!

Adam

 

Glad you sorted it! Guessed it was most likely a mistake from what you described.

Quite tricky following all the different colours to pins etc. Easy to make a mistake but at least a relief to find it was a simple fix!

 

Can I ask a Q?? As you have built your own loom. I'm running a qpeng aum mk2 and have the loom as built by Ben, but how much of that loom wiring is used as he doesn't strip the loom out and it seems thick to me. I'm guessing a lot of wires are unused??


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Hi,

I stripped out all of the loom i didnt need but it took ages to unwrap it all. I would imagine Ben would be more likely to cut the plugs back, add the additional wires he needed and re-wrap it as its his business/time. Mines only about 14mm at its widest. This may not be the case though.

Hope this helps

 

Yup I have another spare aum loom and fancy stripping and building a loom a bit more custom to the bay.. And thinner. Do you have a pin out diagram? It might be worth buying a ecu plug and building my own.


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