fuel pump wiring

Gannon · Post by **Gannon** » Fri Dec 21, 2007 5:27 am

sounds to me like a dodgy distributor. If the ecu isnt getting a signal from the dizzy, it wont run the fuel pump, niether will it make spark

discopotato03 · Post by **discopotato03** » Fri Dec 21, 2007 11:53 am

Subafry the question we really need to know is has this car actually run with the Microtek computer or has it just been fitted ?

Usually the biggest PITA fitting aftermarket management is getting the computer to talk to the crank trigger/engine speed sensing device . The computer has to know where the dizzy/or CAS is otherwise it won't have a clue where the crank (pistons) are in their 4 stroke cycles .

If this is the case more importantly are you attempting to use the the early mechanical/manifold pressure distributor (3 plug type) or the optical CAS/distributor (4 plug type) .
If its the early one and you want to have the Microtek control ign timing you have to index it to the correct spot (internal bit on top of the shaft that the rotor button fits on) and defeat its mechanical/vac movement .
If its the later optical type this is already done but you may need to change its optical cutter disk so that the Microtek gets signals it can understand .
If you want to have sequential injection the CAS must have a "home" or reference pulse to tell the computer that the CAS is coming up to top dead center on No1 cylinder . Then it needs four more for the ign pulses as they fall due . You would have to set the Microtek for the Subarus different firing and injecting order as well - I think 1324 instead of the normal inline fours 1342 .

Aftermarket management is not plug and play and fitting it is only half the fun . The tune can only be as good as the tuner and aftermarket systems generally use the hateful manifold air pressure (MAP) sensors as the load sensing device .

Sorry to be so negative but on an EA82 an interceptor and a std system is hard to beat particularly if the car had EFI to start with .

Cheers A .

AndrewT · Post by **AndrewT** » Fri Dec 21, 2007 12:47 pm

Matt's car has been running with the Microtech MT8 for ages, long before he bought the car.
He obviously hasnt been online to update this today just yet...but he told me yesterday he may have tracked the problem down to a faulty 20c transistor on the ECU's circuit board. Apparently it's a common problem with that model!

Xtreme_RX · Post by **Xtreme_RX** » Fri Dec 21, 2007 1:02 pm

EA series EFI motors are not sequential injection........

D3V1L · Post by **D3V1L** » Fri Dec 21, 2007 4:29 pm

matts car has run with the microtech computer since the year 2000..with no problems..long before he got to it

last night i attempted to source the problem....i ended up nailing it down to the ecu, was not putting a signal out of the comptuer to the fuel pump..so i wired it up to ignition temporary just so it can be deriven....started up and ran absolutley fine..

then we put everything back together and ready to go...and presto..no spark either...funny thing is nothing else was touched in that period it ran last time....so my knowledge has come to a dead halt and have no idea whats going on...but the fuel problem definetly sounds like the transister issue that is apparently a common problem....

as for the spark......th coil is getting power but theres nothing at the plugs...
dave

discopotato03 · Post by **discopotato03** » Fri Dec 21, 2007 5:38 pm

If its getting power to the coil/s it sounds like whatever controls the ignitor/s isn't doing its job .

ECU electronic issues are a pain because they can cause all sorts of intermittent problems .
Id say the best plan would be to go find a Microtek dealer and say fix .
If there's some money to be spent then you could possibly update to a current box with better software and hardware .

Yes EA82 MPFI/T are not sequentially injected . From memory they only have two injector drivers in the std box but don't remember how they are paired .
Having batch or semi sequential injection means the injector timing is all over the place in relation to the valve timing . This means its not optimal like sequential is so the idle and low load mixtures are never as clean . With a reasonably sophisticated computer ie Autronic they only use sequential injection and you can set the injection timing (usually the injector closing timing) wherever you want it in the 720 degree cycle . By 720 degrees that means the four strokes and two complete crank revolutions per cycle . The down side to sequential is you need injectors big enough to inject each cylinders complete fuel load at full engine load in the time available .

Cheers A .

Subafury · Post by **Subafury** » Fri Dec 21, 2007 5:41 pm

yes what they said

i bought some transistors and will crack open the ecu and replace them if no other causes are found.

Subafury · Post by **Subafury** » Sat Dec 22, 2007 10:17 am

had another go last night. after cracking open the ecu d3v1l, alex, matatak and i found that a scratch had some how made its way onto the circuit board cutting two connections. after very carefully soldering bypassing wires these connections were all good again. but car still had same problem. no fuel pump activation from ecu and no spark. the transistor things seem to look alright to me so i dont think they are the problem.

im offering money now to anyone who can fix it- apart from microteck which will take months- and i need the car back running asap. come round sunday arvo and do some more prodding round coz im beat and dont know what else to do.

AndrewT · Post by **AndrewT** » Sat Dec 22, 2007 1:23 pm

Dave says the coils are getting power but theres nothing at the plugs.
Surely this has to mean either the coils or the spark plug leads are faulty?

Matatak · Post by **Matatak** » Sat Dec 22, 2007 1:36 pm

there is only one coil...but i dunno if it is good or not. i suggested raping Blackmales EA82t for his coil and other parts...but i dunno

his spark plug leads are almost new i think. nice BIG ones to.

coming from the coil it still has to go thru the dizzy aswell Andrewt why didnt u mention that lol

AndrewT · Post by **AndrewT** » Sat Dec 22, 2007 2:02 pm

Oh yeah silly me, was thinking EJ.
Stupid dizzy stuff!

Matatak · Post by **Matatak** » Sat Dec 22, 2007 2:12 pm

yer evry1 is starting to say

"Ej Ej Ej Ej"

well that was alex neway

hey davarino when u gonna take a looksee

Subafury · Post by **Subafury** » Sat Dec 22, 2007 7:35 pm

stop making cracks about ej. i know it eventually needs one but not just yet as this engine hasnt died yet. and i dont have the funds. im just a student.

i dont know too much about ecus but ive got a funny feeling like the ecu wont let the car run or something if it doesnt sense the fuel signal. which would explain why dizzy, coil, leads and spark plugs are all good. iknow theyre good coz i we managed to run the car briefly 2 days ago.

i think the ecu needs a more thorough check thru of the fuel wire.

Subafury · Post by **Subafury** » Mon Dec 24, 2007 12:03 am

well its finally fixed.
lots of diagnostic efforts were the main thing, but also some scratch fixing on the circuit board and rewiring got the car to run as it should.
the ignition wire for the ecu as we knew wasnt sending out the fuel pump signal so after re routing that, some more weird **** happened that wasnt sposed to, subarino ended up finding a source it would work on and also re wiring my turbo timer properly which also helped things.

still dont know why it suddeenly played up- suspect bodgy relay somewhere- but it shouldnt do it again. i freakn hope not.

big thanks to alex, d3v1l, matatak and electrical magician subarino for helping out to diagnose n solve the problem.
btw new turbo works good

Matatak · Post by **Matatak** » Mon Dec 24, 2007 12:15 am

Thanks Subarino

Genius

now its time to give it some stick tomorrow

Subafury · Post by **Subafury** » Tue Jan 01, 2008 12:36 pm

yeh shoulda re posted on this sooner but turns out problem wasnt fixed.
had to temporarily hardwire the fuel pump wire becaus with it hooked up to its relay weird stuff happens.

with it hooked up properly:
it will start in the morning and run for like a minute then slowly conk out and die like no fuel. then when u go to crank it again- no fuel. or priming.

the way i have it hooked up to run now is dangerous, and also i have no gauges at all.
any thoughts as what this could be- need it fixed asap

tex · Post by **tex** » Tue Jan 01, 2008 2:17 pm

Don't know if this will help at all if not it may help someone else out but you are able to get a special LPG contoller relay designed for pre ECU cars And its designed as a roll over shutoff all you do is run one wire straight to the battery one to the dizzy or coil wire one to earth and one to gas solenoids (In your case the fuel pump) And that way you can Hot wire it safely some of them even come with a built in fuse!

Subafury · Post by **Subafury** » Tue Jan 01, 2008 4:53 pm

that does sound like a good idea tex. ive since had a tinker and sorted out stuff and it all seems to work now except for my temp gauge in dash. there was dome dodgy un soldered wires that came apart. fingers crossed everything stays good.

Morcs · Post by **Morcs** » Tue Jan 01, 2008 9:32 pm

Another idea is to use a hobbs switch (oil pressure switch) used on tractors etc to operate some things that you only wont to operate when the motor is running (makes contact when there is oil pressure). Would also need to operate the relay when cranking to start.