No Spark In Ae71 Conversion

[Moses_33]

Hey guy's,

I am stuck at the moment. I am trying to do standard 4-age conversion in an AE71. So far everything has been going well but we have hit a serious snag.

 

We have NO spark!!! :) Now we have checked the dizzy and at first that was the problem. Test revealed it was 250 ohms. So got a new dizzy from a known working car and it tests at 160 ohms. Smack bang in the middle of where it is supposed to be.

 

Connected it up and still nothing. We are at a loss as to why it won't go and it is now giving me the shits as I just want her on the road so I can drive her again. So any ideas as to what to try? The engine we are using has come from an AE82 1987 FWD hatch and has gone into a RWD AE71 wagon. My brother-in-law has been helping me as I am technically challenged but learning fast.

 

We have a wiring diagram for the AE82 and it appears to be the one we need. We also have one for the AE86 and it is different to the ECU we have. (No fail safe in the ECU we have but the AE86 appears to have one according to the diagram.) Power seems to be ok. Fuel pump works fine (brand new) and clicks when power connected.

 

We have power to the coil and ignitor and they test fine. Injector pulse was ok but it has now been lost. Does the ECU need to be ground to the car body similar to the enginie strap? Or is there something real basic that we have missed?

 

Cheers

Moses33

 

Down in the NSW side of Canberra and I have asked all the guys in the ACT section and they have run out of ideas as well!!

[Damon550]

got a pic of all the wires going to the coil?

[Trev]

If you have lost spark and injector pulse then the ecu isn't receiving the signal from the dizzy, Check the wiring and make sure it is plugged in properly.

[Moses_33]

Thank you both.

 

Turns out the Ignitor was plugged in incorrectly. Missing a couple of relays between ECU and Ignitor. Now have spark and crank so we should be up and running in the next couple of weeks. Brother-in-laws baby arrives tomorrow so will not get looked at for a few days lol!!

 

Thank you again for your advice

 

Moses33

[awvg]

i also have no spark. tried adding a relay between ignitor and coil but still no luck. is this were you added your relay?

[Moses_33]

Ok,

Have spark, have ecu that works have checked with voltmeter, have injectors that manually test fine by supplying direct power and gently doing a blow check, have checked wiring with voltmeter and continuity reads fine.

 

Have done the tests that the test book recommends and yet do not have Injector pulse. I can get the car to start on the cold start injector only but as no pulse through the main injectors it cuts out.

 

Dizzy appears ok ohms test gives reading of 160 ohms which is in the middle of being fine. It seems to give spark not a problem.

 

Anyone have any ideas?

 

Moses33

[ke70dave]

can't quite work out what you have/havnet checked, but i suggest the following:

 

-connect up a check engine light, so you can tell when the ECU is on, and you can check for ECU error codes

-there is a chunky orange wire in your engine loom, which powers almost everything important make sure this has power from ignition.

-make sure you have +12V on one side of your injectors (this is from the formentioned chunky orange wire)

-make sure any grounds on the engine are in good order, especially the ground that is bolted to the inlet manifold. its a bunch of brown wires form memory. also make sure the ground that goes from engine to chassis is in good order too.

[Moses_33]

Thanks KE70DAVE

 

I know the grounds are good cause we replaced a couple of them with heavier duty wire.

 

I will double check the +12V to the injectors. As it is a conversion from a 4AC to a 4AGE we ran a sort of relay, It's off the switch (ignition) at the battery. No ignition no power to the ecu a sort of extra protection from thieves as it looks like an alarm relay so if they cut it well you get it.

 

I used the original wiring (loom) as much as possible and I don't think we had to re-wire the injectors. But will check tomorrow.

 

Thanks again

Moses

[Moses_33]

Connected the check engine light. Came back with an error of Ignition Confirmation.

 

Have checked everything again and the only thing we can think of is the ignitor could be faulty.

 

Thanks again for all the help

Moses

[cinky]

this probably wont help you but when this happened to me it turned out that the over sized wheels rubbed trough the pulse wire from the ecu. makes it seem as though the igniter doesn't work. ooohhh and good luck trying to find a new igniter they can be hard to find if you aren't exactly sure on where to look.

[Moses_33]

OK.

 

This is really starting to piss me off!!! The saga is continuing and it has stumped many people I have spoken too. Here is the list we are at so far.

 

Have no error responses from the ECU now.

Igniter is working and we can hear the pulse through the old Screw driver check

Fuel Pressure check has confirmed pressures however the pressure is an average 10 psi higher than factory (probably due to an after market

VL fuel pump)

Timing has been confirmed correct with a timing light

 

We can get the car started but when the cold start injector stops the car dies. We cannot seem to get the throttle to bring the car up either. It seems as though there is a fuel starvation problem but we cannot work out why. We have tried two MAP Sensors and they have not fixed the problem. We have checked wiring and everything comes back as you would expect. We have also checked the TPS and it appears to read correctly according to the test page. So why won't the bastard start?

 

Has anyone got any ideas on what they have tried. and yes I have tried Google and it revealed a few people with the same problem but no hits on how to fix it. Even tried the Diagnostic Check Book from Toyota and it hasn't helped.

 

Moses

[Trev]

Have you got the fuel delivery feeding the right way?

 

Check the cold start injector circuit, in failing that try another ecu (ke70dave has a spare one).

[Moses_33]

Thanks Trev.

 

Fuel delivery in through the front of the fuel rail out through the regulator. Check. Fuel pump... Check and Fuel filter (efi in line ) Check.

 

Bought second ECU thinking that was the problem initially and same result. (unlikely to have two faulty ecu's but I know it can happen.

 

Will check the cold start injector circuit today...

 

Cheers and thanks heaps

 

Moses

[redae71]

so you still have no injector pulse? if so that why you can't rev it and it dies, there are only so many things in an efi system that can cause the problem you have, you have spark so forget that system, focus on your ecu and the connections having anything to do with injector pulse, i.e. double check your 12v injector wires and test continuity between injector grounds and ecu, when i did my engine conversion the injectors were stuck closed due to sitting so long but i think you already tested that....... i ran it on aerostart for a while and it freed them up then got them cleaned once i new there was no major wiring issues

[Trev]

Red AE71 just pointed out that you most likely don't have an injector signal going to the 4 injectors, have you got an LED test light or a noid light handy to see if you have injector pulse?

 

If this is the case then I refer back to my 1st post as a point to start looking, I have a 4age diagnostic manual I can scan if you run into trouble.