80 Series Crank No Start

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jonheld said:
The COR gets an ignition hot +12 on pin 2 which also hits the second coil.
Pin 4 is the ground path of the second coil that runs to the switch in the AFM.
When the flap opens, the switch completes the ground path and the COR fires the fuel pump.

On a related issue, have you bypassed all FP logic by shorting pins 1 (FP)-8 (B+) in the diagnostic connector on the firewall?
That should fire the FP with the key in the ON position, bypassing the COR and associated logic.
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Thx, just printed out page for bypassing pin fp and b+ from your webpage, will try!..... FYI I own an low voltage av company in Buffalo NY. Thx again Jon, Ill get it. Its just a tractor with efi. :)
 
smallv8 said:
Thx, just printed out page for bypassing pin fp and b+ from your webpage, will try!..... FYI I own an low voltage av company in Buffalo NY. Thx again Jon, Ill get it. Its just a tractor with efi. :)
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Ok jumped pins fp and b+ and key to on. I heard fuel pump for first time. So I either have bad ground at COR or broken wire to amf. I also have new toyota fuseable link coming in today. I do have continuity from post to post on fusable and volt meter light illuminates with key on.

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IMG_2462.webp
 
smallv8 said:
Voltage on amf pins is as follows:

Red/white 25.2
Brown/blk 10.2
Blue/grn 10.2

Pins 2,4,7 (no pin on 3) respectfully.
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I'm thinking you might want to recheck those readings. You're not getting 25.2 volts on anything in a 12 volt system.
In any case, voltage readings with the AFM disconnected are irrelevant, so I'm not sure what you're looking for.

I would put things back together and try starting the engine with the diagnostic jumper in place.
If error codes come up then we have things to look at.
 
jonheld said:
I'm thinking you might want to recheck those readings. You're not getting 25.2 volts on anything in a 12 volt system.
In any case, voltage readings with the AFM disconnected are irrelevant, so I'm not sure what you're looking for.

I would put things back together and try starting the engine with the diagnostic jumper in place.
If error codes come up then we have things to look at.
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Jumper from b+ to fp, crank no start. Jumper from te1 to e1, 2-4-3-1

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smallv8 said:
With afm plugged in but sitting on air cleaner, b+ to fp and key to on position, gently pressing the flapper door open manually I hear the COR relay trigger at kick panel.
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OK, you don't need the jumper if you've got the AFM plugged in.
The jumper bypasses ALL FP logic and will fire the FP as soon as the key is in the ON position.

With the AFM plugged in and the jumper removed (normal running setup) you should hear the FP kick on when you open the flap.

Please refer to the schematic from the ENGINE CONTROL section of the Toyota EWD:

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smallv8 said:
With afm plugged in but sitting on air cleaner, b+ to fp and key to on position, gently pressing the flapper door open manually I hear the COR relay trigger at kick panel.
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jonheld said:
OK, you don't need the jumper if you've got the AFM plugged in.
The jumper bypasses ALL FP logic and will fire the FP as soon as the key is in the ON position.

With the AFM plugged in and the jumper removed (normal running setup) you should hear the FP kick on when you open the flap.

Please refer to the schematic from the ENGINE CONTROL section of the Toyota EWD:

View attachment 4135970
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Proof of concept, all jumpers removed, afm plugged in (bench testing on air filter), press door open, hear FP and cold injection port. Previously stated she has been running really rough last month. then just died last Thursday. Short inside AFM after 264,000 miles? Thx Jon.
 
ppc said:
Don't know the website or document you are getting this information from but it surely not Toyota created. There are no MAP or MAF in your vehicle. Don't rely on AI BS.
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I referenced jons print out as well, it checks out, Im in IT I 100% agree with you!

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image.webp
 
jonheld said:
OK, you don't need the jumper if you've got the AFM plugged in.
The jumper bypasses ALL FP logic and will fire the FP as soon as the key is in the ON position.

With the AFM plugged in and the jumper removed (normal running setup) you should hear the FP kick on when you open the flap.

Please refer to the schematic from the ENGINE CONTROL section of the Toyota EWD:

View attachment 4135970
Click to expand...
New rebuilt oe afm in, still crank no start. Gonna check grounds
 
smallv8 said:
New rebuilt oe afm in, still crank no start. Gonna check grounds
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When I built my wife's 80, I pulled the inner fenders and coated them with KBS (a product like POR-15). When I put everything back together, I got the crank and no start. Left me scratching my head... it ended up being the battery to body ground... sanded off a little of the KBS to expose bare metal, reestablished the ground and the rig started right up.
 
Old Nick said:
When I built my wife's 80, I pulled the inner fenders and coated them with KBS (a product like POR-15). When I put everything back together, I got the crank and no start. Left me scratching my head... it ended up being the battery to body ground... sanded off a little of the KBS to expose bare metal, reestablished the ground and the rig started right up.
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Cleaned up ground. Crank, no start. I did notice with new afm, COR is triggering fuel pump "on" when starting. Getting a fresh set of eyes on everything tomorrow by another mechanic friend.
 
smallv8 said:
Cleaned up ground. Crank, no start. I did notice with new afm, COR is triggering fuel pump "on" when starting. Getting a fresh set of eyes on everything tomorrow by another mechanic friend.
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It’s good to tick the simple things off the list. Sorry that wasn’t the culprit.

There is one other thing (simple) that “could” be a problem. Is your factory alarm system still installed?

The one in my wife’s rig gave me all sorts of fits. Crank and no start, no crank at all, etc. when I pulled it, those problems stopped… the ground issue was just me being an idiot… lol.
 
Old Nick said:
It’s good to tick the simple things off the list. Sorry that wasn’t the culprit.

There is one other thing (simple) that “could” be a problem. Is your factory alarm system still installed?

The one in my wife’s rig gave me all sorts of fits. Crank and no start, no crank at all, etc. when I pulled it, those problems stopped… the ground issue was just me being an idiot… lol.
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It had a silly viper alarm but I removed last summer.
 
smallv8 said:
New rebuilt oe afm in, still crank no start. Gonna check grounds
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New oe rebuilt afm, COR is triggering fuel pump and cold injection w/out jumpers. Still crank no start. Checked all obvious grounds. Fresh set of mechanics eyes on it tomorrow. Getting closer.
 
jonheld said:
Does the fuel pump fire when you turn the key to start?
The starter circuit fires the first coil in the circuit opening relay to fire the fuel pump while cranking before the flap in the AFM opens.
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Yes I hear fuel pump hum and now smell gas in engine bay
 
smallv8 said:
She was running a little rough figured had to do tune up, went to jobsite and she died, crank no start.
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Going back to your first post. Had you actually gotten around to the tune up? I'm guessing no but trying to eliminate variables.
Consistently running rough for a month then immediate crank no start? Seems like something a failing electrical connection would act like, but you've tested this area pretty thoroughly.
I re read the thread and don't see that you verified compression. Update us there?
Another thing that could explain this is a disintegrating cat. Could be that your exhaust has been getting clogged, then finally the whole thing fell apart and you now can't breathe. Any hissing after the engine stops turning? Can you pull an 02 or crack a union open and try to start?
 
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