2.3L ('83-'97) Efi spark timing way off

[neinnein_nein]

I have gas pressure and gas, the vacuum jumps from 0-6 during cranking at the brake booster line But I don’t have spark WHILE cranking, only when I stop cranking. Occasionally that spark will cause a little knock because it’s trying to fire up but it’s always too little too late.
Pardon my language but it sounds like my spark is too retarded?
I tried with and without tps hooked up. I tried without the purple wire hooked up to the I on starter solenoid that sends a message to ECM to retard the spark. Still the same. Uploaded a video of what happens exactly. She really wants to fire up:

 

[RonD]

The ignition switch has TWO separate 12volt wires that supply voltage to the coil and spark module
One when key is in RUN(on) and a separate one when key is in START

In the "old days" the RUN wire had a ballast resistor or resistor wire to lower the voltage at the coil so it ran cooler, but this was bad when trying to start the engine cold, so START 12v didn't run thru the resistor

It reads like your START wire doesn't have 12v

Diagram here: https://www.therangerstation.com/tech_library/EDiagrams/files/Diagrams_StartIgnition83to88_2_3.JPG

Upper right, red/light green wire sends 12v to spark system in RUN, when key is turned to start, the RUN 12v is disconnected
Then Brown/pink wires sends 12v in START
So you get that POP when key is turned back to RUN and coil gets 12v again

To test for this run a jumper wire to Coil "+" terminal from battery positive
Then try to start engine
If it starts then thats the problem

Ignition switch is under the steering column above brake and gas pedal

 

[neinnein_nein]

Thanks Ron. Sounds like you put me on the right track there. I see those wires under the wheel but it’s hard to say where they are going—will follow them.
i tried hooking up coil to battery + and the engine cranked and there was a very very loud detonation that sounded scary, a bit of smoke from the valve cover. I hope I didn’t break a valve or something similarly unfortunate.

 

[neinnein_nein]

it looks like for the 84 2.3 / 2.0 the brown pink ended up on the right side of the starter relay then sending power to coil while cranking like you said.
Just hooking up coil to 12v didn’t seem to do it—I’ll try this..

 

[RonD]

That diagram is a bit misleading

The brown/pink on the starter relay would be hooked to the "I" post on the relay, and probably wouldn't be used if ignition switch also had the brown/pink wire, there would be no need for both

Yes, engine may have been flooded out when you did the "hot wire" to coil, so lots of gasoline fumes in the crankcase needed to be burned off, no it wouldn't hurt anything but could blow off breather hose and PCV valve out of valve cover


To test if lack of 12v is the issue you can also hook up a test light to coil "+" and ground, light or meter should show 12v key on and then stay on when cranking
If light goes off or volt meter drops when cranking thats the problem


Starter relays often have 4 posts
2 larger ones and 2 smaller ones
Smaller ones are labelled "S" and "I"
"S" post is what activates the relay, red/blue wire from ignition switch

When activated one larger post and "I" post both get 12volts
"I" post was hooked to coil "+" and was used to by-pass the Ballast resistor for cold start

In the diagram it shows the brown/pink wire hooked to starter motor wire, this would be BAD, because the red/green wire has 12v key on, so starter motor would get 12v, as soon as you turned on the key

 

[neinnein_nein]

you’re right it is weird they would put brown pink on the same circuit as starter motor, it would constantly crank.
I hooked up ignition power supply to the red/lt green wire and now I have healthy spark in start and the spark pop when I cycle back to run (I assume that would continue if the engine started). Still unsure why it’s not firing up with almost 13v at the battery and what seems like healthy fuel pressure (my fuel pressure gauge arrives tonight in the mail).
I have a boost gauge hooked up to the turbo compressor that drops to minus 30 while cranking—not sure if that’s relevant. Still getting jiggle between 0-6 psi vacuum at the brake booster when cranking. Maybe I’m not getting the fuel pressure I think I’m getting—will find out tomorrow when I install the gauge.

there is spark at the plugs too.

 

[RonD]

Check that the CAM gear is turning, very common for a timing belt to break on startup without driver noticing
That would also cause the 0-6 vacuum
Should be a steady 2-3" of vacuum while cranking, no jumping

 

[neinnein_nein]

Check that the CAM gear is turning, very common for a timing belt to break on startup without driver noticing
That would also cause the 0-6 vacuum
Should be a steady 2-3" of vacuum while cranking, no jumping

Wow it’s insane how well you know those engines. So cool.
Not sure if it’s good or bad news but the cam is turning and there seems to be healthy tension in the timing belt.
I did manage to run a check engine light self-test at the wiring harness and it's giving me the following, but i'm not sure that affects ignition:
ECT out of range
Air charge temp indicated -40NF or circuit open
MAF circuit below minimum voltage (not sure why because it's plugged in and seems pretty clean and good)
air management circuit 2 failure (?)
canister purge circuit failure (because it's not plugged in)

 

[Shran]

Kind of sounds like your harness is missing a ground somewhere with that many sensors reporting failure.

I am assuming you are using a harness, ECM, etc from a much newer truck since you're talking EFI stuff here and not a carburetor like an '84 would have? Might be helpful to know what year/model your EFI components came out of.

 

[neinnein_nein]

Kind of sounds like your harness is missing a ground somewhere with that many sensors reporting failure.

I am assuming you are using a harness, ECM, etc from a much newer truck since you're talking EFI stuff here and not a carburetor like an '84 would have? Might be helpful to know what year/model your EFI components came out of.

Im thinking of one ground that might not be optimal now that you mention this—the one on the intake manifold bolts.
Yeah sorry the full story is I rebuilt a 1988 thunderbird turbo2.3 and put it in my 84 2.0 with a Ron Francis harness. Trying to start her for the first time. Really not a pro but tried to do everything by the book and I’m wondering where the problem is..
Using a 8UA ecm which is supposedly compatible with the big VAM from the 88 tc Im using.

Im not w the truck now because it’s in a driveway far from my place and there’s a rainstorm, but looking at photo, it looks like I might have installed the VAM/intake backwards. That would a great way to NOT allow air into the system, right?

 

[Shran]

Gotcha!

I'd pick a sensor, maybe the ECT would be easy but it doesn't matter, really. See if it has continuity to ground and also continuity back to the ECM and that it has power, and that the ECM is grounded.

 

[RonD]

+1 ^^^^

Most of the sensors share a 5volt wire from computer, its just spliced at a few places, on the Ford harness it was a grey/red stripe wire seen at each sensor
Look at the wire colors on a couple of sensors and there should be one wire thats the same color code on each, thats the reference voltage from computer

 

[neinnein_nein]

+1 ^^^^

Most of the sensors share a 5volt wire from computer, its just spliced at a few places, on the Ford harness it was a grey/red stripe wire seen at each sensor
Look at the wire colors on a couple of sensors and there should be one wire thats the same color code on each, thats the reference voltage from computer

Confused..
I flipped the VAF so it faces the right direction.
the VAF sensor reads 5v key on (but I still get an error code 66 saying MAF below minimum voltage)
the ECT and knock sensors both gave me 19volts(!) key on. Then I cut the wire that’s a ground to upper manifold and routed it to my ground strip on the wheel well, where everything is grounded. Both sensors now read 60 volts!! Cranked noticeably slower although battery still at 12.6v, no start, then it started raining and had to fold the operation.

going back in the morning to look for a better ground. But I’m a bit confused to say the least..

will reread Ron Francis harness instructions and try to find answers in my Ford EEC book but if anything comes to mind, let me know..

 

[RonD]

Some wiring diagrams here: https://www.therangerstation.com/tech_library/turbo_swap_wiring.shtml

You can't get higher that battery voltage, engine off, so not sure why you would get those higher voltage readings

VREF(reference voltage) should be 5volts
SIG RTN(signal return) should read as Ground
But these can be reverse on some years

Those are 2 of the 4 wires on VAF unit
One of the other wires is for VAT(air temp)
And one for VAF(air flow)
These 2 should read less than 5volts, thats the sensor voltage the computer uses to determine air temp and air flow respectively

 

[neinnein_nein]

Some wiring diagrams here: https://www.therangerstation.com/tech_library/turbo_swap_wiring.shtml

You can't get higher that battery voltage, engine off, so not sure why you would get those higher voltage readings

VREF(reference voltage) should be 5volts
SIG RTN(signal return) should read as Ground
But these can be reverse on some years

Those are 2 of the 4 wires on VAF unit
One of the other wires is for VAT(air temp)
And one for VAF(air flow)
These 2 should read less than 5volts, thats the sensor voltage the computer uses to determine air temp and air flow respectively

thanks for the diagrams Ron! Looking at videos and doing research, rereading your and Shrans replies and starting to understand more things that didn’t register at first. Thank you both for the info and patience, would be kinda lost without it.
I’ve never tested the harness since it came ready made but now I looked at the diagrams and made a bunch of notes. I’ll make sure the vref at harness is 5v, make sure the power pin nor 1 and grounds are good at harness (pins 40-60), make sure there is 5V between vref 26 and sig return 46. Then I’ll make sure ECT, VAF, VAT and ACT have the right power and return to the appropriate pins which I’ve noted. If something doesn’t seem right and i can’t find the break in the circuit I’ll route all the wires straight from the harness pins to the sensors themselves with the right voltage. Not classy but then it should work. I had to do it for a boost gauge that’s not part of the harness and it seems to be working perfect.
I guess that‘s the trap of getting a ready-made harness as a n00b—if the plug and play doesn’t fire up you have no idea what you just plugged in. So now i know a little more and hopefully can rewire what’s not working, assuming none of the sensors are fried or anything. Everything except the vane is new.

i don’t know if all those problems are what‘s preventing it from firing up but I’m sure it doesn’t help..