Ucon ems

dramad1

Active Member
I do have the viper 5901. Fuse maybe, loose wire.

I uninstalled the ucon and unplugged the maf sensor, started the truck, it started then died two sec later. All fuses have been swapped except the efi relay and the fuel pump. Wires have all been checked and coil plug connectors cleaned. Code p0102 and p0351-0356 show, cleared them and they come back.
 
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sdxrunner619

Active Member
Your MAF sensor is toast bro


Butters, what part of the above bit of diag between me and gadget did you not get????If you remove the MAF sensor, the truck will switch to a speed/density map, and not use it for air/fuel control. Since the truck ran the same with it plugged in/unplggued we can determine that the MAF is is not part of the issue. :rolleyez:

/End maf sensor debate


I dont know a terrible lot about aftermarket alarms, does the viper alarm system disable spark? :hmmmm2:
 

butters607

Active Member
Question when the maf is plugged in it won't start at all right. Oh on that efi relay do a ohm test and see if you get anything out of it
 

dramad1

Active Member
So I'm down to efi relay, and injector coils. Maybe an issue with the fuel pump?? Or pump fuse. I can hear the pump though when I go to start it.
What about the starter or alternator? Would there be something there that cuts fuel to injectors. Maybe an o2 sensor?
The efi relay seems to be an issue in older model toyotas???
 

sdxrunner619

Active Member
A/f and 02 sensors only work once the trick is running for some period of time. Not them.

If the engine starts, its not the starter, its not the alternator. Reason your battery died was from you starting it so many times with out it running long enough.
 

Torspd

Moderator
Staff member
Are you running larger injectors than stock? If not, then try removing the UCON and and seeing if it will run.
 

dramad1

Active Member
Are you running larger injectors than stock? If not, then try removing the UCON and and seeing if it will run.

I removed the ucon and have the same results. Starts then turns off seconds later.Currently the ucon is not connected. I'm going to check the fuse on the alarm and a few wires.
I have stock injectors and new plugs 20's.
I need to get the efi relay and see if that's the issue as well.
It not the maf, the ucon, the other fuses??? Injector coils? All 6? Should I pull the plugs and look at them?
 

Torspd

Moderator
Staff member
Rules out the ucon. Have you checked all the plugs to make sure that they are properly connected? All of the ones that had to be unplugged during the cam gear install.
 

dramad1

Active Member
Rules out the ucon. Have you checked all the plugs to make sure that they are properly connected? All of the ones that had to be unplugged during the cam gear install.

Yep. Me and Kevin checked all connections like seven times before we fired it up. I have checked and cleaned all of the connectors for the plugs the other day. I'm going to check a fuse in the alarm maybe disconnect it for a min then try to fire it up.
 

sdxrunner619

Active Member
Yep. Me and Kevin checked all connections like seven times before we fired it up. I have checked and cleaned all of the connectors for the plugs the other day. I'm going to check a fuse in the alarm maybe disconnect it for a min then try to fire it up.


The strange thing was that it ran fine that night. The alarm DOES NOT limit or control spark....or so i've been told....:hmmmm2:
 
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