AW11 No Start (not even cranking).

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the night rider
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AW11 No Start (not even cranking).

Postby the night rider » Wed Dec 07, 2016 6:32 pm

So another AW11 no start issue. This one is maybe a little different..

Firstly my car is a JDM 1985 AW11. No AC, Originally automatic.

Just a brief background: I recently replaced the engine with another bigport 4age. At the same time I did a manual swap.
I went to test start the engine but it doesn't even crank at all. Can't even hear the click of the starter solenoid push the gear out into the flywheel. I believe this is due to me messing up the neutral safety switch wiring (which has to be modified when swapping to manual). The reasons for why I believe this to be the problem are provided below.

I have done some basic diagnostics as follows:

- All ground wires are fine; the engine, transmission and chassis are grounded. I checked this with a multi meter (probe on battery "+" and other probe on engine, then chassis, then transmission. By doing this I got +12V at all these points).

- Fusible link is fine. I am getting +12V at starter motor cable all the time and also at the alternator. Also my headlights and indicators work fine.

- Starter motor is fine. I checked this by connecting it to the battery and the solenoid pushes the gear out, the motor also seems to spin fine.

- Starting relay is fine. I checked by providing +12V across the coil terminals and I can hear it click. I also checked the relay coil continuity with a multi meter.


So! This only leaves the Neutral Safety Switch wiring?? I suppose I messed it up because the online picture I found to help me had different wire colours.

What I need help with:
* So now basically what I want to know is if it is possible to send a signal the the ECU connector directly to get it to think the car is in neutral/park.
* I found an ECU diagram which shows the top right pin on the 10p connector being for the NSW (Neutral Safety Switch).
* If I put this pin to ground will the car start up (or at least crank)??
Basically I just want to see if I can get it to crank/start before digging into the wiring again.


Oh and one more piece of information: I tested the starting relay by removing its cover and manually engaging it (by pressing together the switch terminals). When I did this the multi meter shows +12V being provided to the small starter motor connector (Not the battery + cable the starter solenoid cable).
I also hear a click from the boot which means the relay next to ECU is working I think.

Sorry for the long post, just wanted to provide as much info as possible. Any help is appreciated.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Some extra pictures:

Starter testing:
Image

0V at the starter solenoid connector normally EXCEPT when I manually actuate the starting relay and then it shows +12V. NOTE: It's hard to see but one probe is on battery "-" and other probe is in the starter solenoid connector:
Image

This is how I manually activated the starting relay (Obviously has to remove the cover):
Image

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the night rider
Posts: 6
Joined: Wed Dec 07, 2016 5:49 pm

Re: AW11 No Start (not even cranking).

Postby the night rider » Wed Dec 07, 2016 9:03 pm

Update:

Okay, so using a 4age wiring diagram I found the NSW (neutral safety switch) pin on the ECU:
Image

The manual also says that with the ignition on and with the shifter in P or N the pin should be at 0V (meaning 0V required to allow starting to commence):
Image


So I connected a wire from ground to the NSW pin (specifically to the wire going into the connector for this pin).

But no Luck =/ I don't know why.
Turn the key to cranking position but absolutely nothing, dead silent. Even if I have gotten the NSW bypass wrong, shouldn't grounding the pin allow the engine to crank?

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jondee86
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Re: AW11 No Start (not even cranking).

Postby jondee86 » Thu Dec 08, 2016 12:59 am

If you have everything on the starter circuit side hooked up correctly, you should
at least be able to get the starter to crank by closing the starter relay by hand. The
engine may not start, but it would prove the starting side of things downstream of
the relay. The neutral start switch or clutch switch is on the upstream side of the
relay, and can be looked at separately.

Cheers... jondee86
Give a person a fish, they eat for a day. Suggest they search before posting, and they learn a skill for a lifetime.

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the night rider
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Re: AW11 No Start (not even cranking).

Postby the night rider » Thu Dec 08, 2016 1:11 am

jondee86 wrote:If you have everything on the starter circuit side hooked up correctly, you should
at least be able to get the starter to crank by closing the starter relay by hand.


Thank you, good advice. I will try this tomorrow.

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the night rider
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Re: AW11 No Start (not even cranking).

Postby the night rider » Thu Dec 08, 2016 4:11 pm

Alright I tried that suggestion and it works!

Engine now cranks when I manually activate the relay.

But now I realize there is another problem. It doesn't start and I can't hear any noise of the fuel pump when turning the key to start position (or when manually activating the relay.

My first action was to find out if my NSW wiring was incorrect. I found a useful diagram in the 4age manual:
Image

I then opened up the wiring harness and found it was in fact wrong, what an idiot =/

Anyway I corrected it. I then went to start the engine using the key, but again absolutely nothing. It's pretty annoying.

The only other thing I can think of is that the car has an alarm and immobilizer installed. Maybe having no battery for almost a year caused it to reset or not work properly??
So I'm going to remove it and try again. I hate that thing anyway (It's quite old and makes too many annoying sounds).

If anyone can think of anything else please let me know. Thanks.

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the night rider
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Re: AW11 No Start (not even cranking).

Postby the night rider » Thu Dec 08, 2016 8:09 pm

Another update:

I found out the 7.5AMP fuse in the engine bay (labeled AM2 i think) was blown. I changed that.

Now when I turn the key to ON position I can hear a click of a relay (Before could not hear anything). I am also now getting the battery charge and check engine light on the dash which is usual when starting up. However, when I turn the key to cranking position I'm still getting nothing.

I have made the following checks:

- ECU BATT terminal is getting 12V power.
- NSW terminal is at 0V after fixing wiring.
- All other fuses are fine.

Getting confused now.

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the night rider
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Re: AW11 No Start (not even cranking).

Postby the night rider » Thu Dec 08, 2016 9:36 pm

Holy ****, it ran!

Turns out my Neutral start switch modification was still wrong.. I even checked with a multi meter at the ECU terminal but whatever, it works now.

Thanks for the help jondee86!

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jondee86
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Re: AW11 No Start (not even cranking).

Postby jondee86 » Fri Dec 09, 2016 2:27 am

Good skills :) It is possible to solve most electrical problems on old Toyotas
with a multmeter and a bit of patience.

Cheers... jondee86
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