5vz-fe crank no start

you can jump the Black/yellow and the white/red wire and power the PCM directly... then see if the CEL illuminates and or she starts.

 

Well I figured I would give you an update. Tried jumping wires, still nothing. I sent in my ecu to a place called G7 Computers. They have an awesome deal where for 225 bucks they will test it, if its good they will give you a refund, if it is bad they will fix it in 1 business day and get it in the mail back to you Guaranteed. I just received an email saying the computer did have an issue and they resolved it, however they did say to check other things to make sure it wasn't a short somewhere in the system causing this. Long story short that is where I am at! I should get it back on Friday? Hopefully and will update!

 

Interested to see if the ecu repair fixes it. If you are not getting any power to the fuel pump could it the ASD relay. Not sure if these trucks even have them. It is a relay that shuts power to the fuel pump in the event of a roll over (asd - automatic shut down)

 

no, no ASD but there is a "circuit opening relay" for the fuel pump. The PCM needs a signal from the CKP (crankshaft position sensor) or the Starter to close this relay to power the fuel pump.

 

Gotcha, I am excited to see as well. Fingers crossed it does. I did replace the crank shaft sensor, still no go. I am kind of at a loss of words if this doesn't fix it. I guess at that point I will have to take it to a shop. Hopefully it does not get to that point though.

 

This thread is the closest I've found to what I have going on so maybe I'm hoping I can build on this and solve my issue.

My friend brought me her 1997 T100, 5VZFE, ran fine when parked a couple months ago, then would only run on starting fluid.

No evidence of rodent damage to any of the wiring.

They had Replaced Control Switch Relay on passenger side near ECM, replaced Fuel Pump and Filter, no change.

Unfortunately I don't have the sst 09268-45014 adapter to test pressure at the FPR but after reading through this, I am not sure that is my problem, after all.

I have noticed now that the CEL does not illuminate, at all, and that a scan tool at OBD2 port has no communication.

I find it strange that it will try to start on starting fluid (and immediately stall) with no communication to ECM, ?

Doing research now into ECM communication but wondered if there is a common fault, here?

Thanks so much for any input.
Lots of fantastic information, here.

 

I've tested at the TPS port and did not get 5v, but rather around 3v.

I checked all grounds on the engine and they all look great.

Battery is solid.
Checked ECM fuse in footwell at it is good.

 

Checked OBD port and I am getting 5.3ohm at #4 "Chassis Ground"
0 ohms at #5
13.79 V @ #16 (Charging)

If I am not mistaken, #4 is the ground from the battery negative to the chassis?

 

I once somehow crossed wires on a crank sensor 5VZ-FE long ago. Would crank forever and no start. Switched the wires around. Fired right up. Just an idea, could be something with the crank sensor.

 

Wouldn't that cause it to not try and start at all?
It will TRY, and fire up for a moment with starting fluid, but dies right out.

Not getting communication with the ECM I think is the high resistance on #4 at OBD2 port.

I'm going to try and replace the wires on the battery ground, and might was well upgrade the others while I am at it.

"Big 3" I think they're called?

 

I replaced the smaller ground at the negative with a much more robust one, and cleaned everything up.
Still have high resistance at #4 on OBD2 port, no change really.

I guess I will try replacing the other grounds tomorrow.

I don't see the third one off hand, by the airbox?

I do see the one from firewall to engine, seems good, but I will try to replace it anyway

 

Was this problem ever solved?

 

Old thread, but if for some reason this is still an issue, I have seen a 3.4 crank and not start because the crank sprocket ring that the CPS gets signal off of is loose or has broken teeth. This ring is right behind the plastic cover, slid over the crankshaft snout, behind the crank pulley. If the crank pulley is loose, it will allow the crank sprocket ring to move out of alignment and the CPS will never pick up a signal from it. Put a breaker bar on that 19mm crank pulley bolt and see if its loose.

 

I had that same problem today, with a truck that was sitting for a long time. I installed engine yesterday crank no start. My buddy had a really good scan tool helped rule out sensors. So runs great on starting fluid putting a fuel pump in tommorrow. I understand your frustration. Good luck

 

Oops old thread I feel dump

 

Make sure your timing belt didn’t break

 

I am having the same exact problem. No communication to ECU. No spark or fuel, CEL light stays illuminated. I'm tearing my hair out here

 

@TnShooter @Speedytech7

 

no com to ecu is an interesting one, is the OBD fuse good?

 

I agree. I'd check this first too.