New engine harness, now won’t start (4 Viewers)

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Jun 6, 2016
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San Antonio
I just replaced the entire engine harness due to every connector breaking when touched(but most importantly the break in the harness to injector 6. Disconnected the battery before starting and every single plug is connected and accounted for including (engine sensors, maf, ecu, trans, and O2 sensors.

CEL is rapidly flashing (27 times to be exact) and will not even attempt to crank…

Scan gauge just says “connecting” so I can’t see if there’s an engine code

EGR is deleted but was before I replaced the harness and was running fine (on 5 cylinders)
 
I went back over my connections and I hadn’t grounded the engine harness. I connected the ground but there’s still no start but the check engine light is not flashing now.
 
What year/model are you working on?

So it cranks but doesn't fire?

IIRC for the FZJ80 there are at least four grounds in the engine bay: left inner fender, right inner fender, right rear side of head to firewall, and left side of head (at lifting hook) to the ignition coil bracket, and one more
at the front/side of the intake manifold.

If you turn the ignition key to the ON position does the check engine light come on for a few seconds? If not there might be a problem with your fusible links coming off the positive battery cable.
 
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Sorry, it’s a 1997. The grounds I removed (3. Engine, firewall, and another small one by intake manifold) are all back in their original places and accounted for. The truck is not turning over so I’ve got no cranking whatsoever. Fusible link is newish but could still be bad I suppose
 
Sorry, it’s a 1997. The grounds I removed (3. Engine, firewall, and another small one by intake manifold) are all back in their original places and accounted for. The truck is not turning over so I’ve got no cranking whatsoever. Fusible link is newish but could still be bad I suppose
Check the ground wires at each fender. One behind the battery to the fender, and one same on the passenger side.

Also, your fusible links. You need to check for continuity across all legs and confirm where you do have power and where you don't.

What's the voltage on your battery?
 
OE maf as far as I know. I’m the 2nd owner and the last harness doesn’t seem repinned
 
I’ve got 12.48 volts at the battery and across both terminals of the FL
Your battery is a bit low, make sure it's fully charged.

However, it should have plenty to crank some.

Something is not connected somewhere.
 
Your battery is a bit low, make sure it's fully charged.

However, it should have plenty to crank some.

Something is not connected somewhere.
That’s what I’m thinking but I’ve been over the harness multiple times now. Knowing my luck, it’s something easy and dumb
 
That’s what I’m thinking but I’ve been over the harness multiple times now. Knowing my luck, it’s something easy and dumb
Have you tried shifting it to neutral to see if it will start?

NSS.
 
I just replaced my harness on Wednesday of last week. We missed a one wire on the passenger side and got no crank. Immediately fixed and got the engine to turn over but it died immediately. Tried two more times and it fired up and idled perfectly.
 
Everything connected at the starter?
 
IIRC, a rapidly flashing MIL signals an ECM fault. Here's the troubleshooting section.

FWIW, all the engine troubleshooting procedures are in the Engine/Mechanical/Troubleshooting section of the FSM.
 

Attachments

  • 1995, Engine Control, Troubleshooting, ECM Power Source Circuit (EG 328-331).pdf
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Well, I was gonna send a video but seems like a pain to do. Yes, check engine light is on with the key in the on position and so is the battery light. No crank whatsoever and like I said before, all connectors are connected and accounted for.

There is one connector that runs to the starter, maybe I should disconnect it and reconnect it to see.

Battery has been on a tender and is fully charged so I don’t think that’s what it is.
Check engine light is no longer flashing now that I’ve connected the harness ground properly…i just have a no crank issue
59376226-6127-4D28-878C-9E63CA8E9793.jpeg
 
I guess what I need to figure out is what connections of the harness would prevent the truck from cranking. Connection to the starter, ground…knock sensor? Bad main relay? I could get a new fusible link just to get one but I believe mine is still good
 
Here is the entire starting circuit. If the starter isn't turning then your problem should be here.
Battery
FL AM1
Junction block
AM1
EA2 connector
Ignition switch
I13 splice
IH1 connector
Neutral safety switch
E19 splice
Starter

My guess is you aren't getting 12V to starter at pin B. You just need to figure out why.

1667963796188.png
 
Here is the entire starting circuit. If the starter isn't turning then your problem should be here.
Battery
FL AM1
Junction block
AM1
EA2 connector
Ignition switch
I13 splice
IH1 connector
Neutral safety switch
E19 splice
Starter

My guess is you aren't getting 12V to starter at pin B. You just need to figure out why.

View attachment 3163159
I printed this from the electrical service manual yesterday to check but I hate this daylight savings junk. The truck is in my driveway and I don’t want to mess with it when I get home from work and it’s already dark. Gonna have to suck it up and check that circuit. I think you’re definitely right.
 

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