Bigport 4age spark problem

**Spode** · 11-07-2006, 07:36 PM

Hey dudes, I have done a search on 4ages not getting spark and havnt found the info I was after.

I have recently installed a bigport RWD 4age into my ke55 corolla from another ke55 where it was running without any big problems (well none which where spark related). We have swapped over the entire loom (no cutting or anything) and gone to start it and havnt got any spark. We have fuel pressure in the rail and the injectors are pulsing so thats not the problem. The dizzy and ign coil are working fine so Im thinking that its either the ignitor or somthing else ECU related because when cranking the coil is recieving NO power at all. Any ideas as to where I can go from here?

Cheers,
Tom

**slide86** · 11-07-2006, 08:43 PM

gday.

1) ensure that you havent put a wire from the -ve side of the coil to ground. there should only be the trigger wire from the igniter going to the - ve.

2) ensure good earths from the engine to the chassis, and from the chassis to the - ve of the battery.

3) good +ve power to the coil and ECU

**Spode** · 11-07-2006, 09:18 PM

yep the -ve side of the coil goesnt go to ground from what I can see, it goes into the rest of the loom.

Yep all earths are good. the battery earths to the block (origionally to the chassis) and there are solid earths to the chassis from the block.

Yep the comptuer is getting a healthy 12v and is operating the fuel pump so im taking that as a good sign that it isnt fried. So im getting 12v to the computer but nothing to the coil?

Any ideas?

Cheers,
Tom

**TurboRA28** · 11-07-2006, 09:43 PM

With IGN on does the +ve side of the coil have 12v on it?

**Spode** · 11-07-2006, 09:48 PM

yeah! it does, why would it suddenly loose power when I turn the key to start?

Cheers,
Tom

**TurboRA28** · 11-07-2006, 09:53 PM

does it do that? loose power on the ign+ wire on the coil when you crank?

the ign+ wire should retain power when cranking. from memory some ignition switches do have 2x ign wires, one that is ign+ and one that is ign+ & start. Some old mazda's are like that.

**jonra23** · 11-07-2006, 09:58 PM

A lot of older points ignition cars are like that to supply power through a resistor to coil when running about 7volts, and through a different wire with no resistor to supply 12 volts when cranking.

run a hot wire to coil to see if will start.

**Cuzzo** · 11-07-2006, 09:59 PM

Did you wire the ecu to a non-ignition power source? Maybe its a ACC power source? Cutting ecu power on ignition? If you have maintained the exact same loom. try to think of things you have added to the loom.

If not maybe its under the bonnent problem which i cannot help you with.

**TurboRA28** · 11-07-2006, 10:06 PM

run a hot wire to coil to see if will start.

Good idea that will eliminate any bad ign power source.

**slide86** · 11-07-2006, 10:07 PM

jonra23 has a good idea. get a wire of decent size and put it straight from the + ve terminal of the battery to the + ve terminal of the coil.

then try to start it up.....see if it starts then.

**30psi 4agte** · 11-07-2006, 11:58 PM

it does sound like it is wired to the wrong side of the ignition barrel !

I have had this one before

**Vios-GT_07** · 12-07-2006, 02:41 AM

something's not grounded properly? hmm.. just a thought..

**trd3sg** · 15-07-2006, 07:44 PM

i had the same drama wiring my aftermarket ecu in my celica -

problem is as cuzzo has noted - you will have wired into the wrong ignition source - you need to tap into the barrell which has power when cranking - have someone test voltage while cranking

**Spode** · 22-07-2006, 02:26 PM

Hey again, Can anyone tell me quickly what wires to the ECU are required to start a 4age?

Cheers,
Tom

**mrshin** · 23-07-2006, 11:23 PM

Make sure there is power everywhere while the engine is CRANKING. Also make sure the igniter is properly grounded... Along with everything else that needs to be grounded!