Thanks for the information that was the problem. I grabbed the upper throttle body off another p5000 here and it works. I am going to try and clean it more and see if I can get it working, I called Leavitt and they want $1100.00 for that throttle body.

Thanks again.

The relief valves mentioned are in the injector holder, not in the throttle body.
The injector holder assembly sits atop the Electronic Throttle Control Actuator (ETCA in Nissan jargon).

WOW That sounds great. So is the throttle body assembly you are talking about the one on the top that the injector, TPS and engine solenoid?

Sounds to me like one of the non-serviceable pressure relief valves in the throttle body assembly has malfunctioned. They stick open and allow fuel to pass through without building to pressure. If I remember right there was a bulletin on this a few years back and the remedy was to replace the assembly. You will need to install a new throttle body assembly or swap for one that is working to test it. Easy quick repair but spendy component.

I still don't have this working. I took the injector and the engine sensor off another p5000 we have it still does not work. I have cleaned out everything. I'm now needing to locate the correct volts for the injector wiring and the sensor if anyone knows that. I have changed over the relays to see if I had a bad relay.

Thanks,
Leigh

sounds to me like its over fueling the system. bad main injector will cause this or possibly a bad injector housing. if it seems to run when you relief pressure off the system this seems to be the more likely scenario imo.

also if no coolant was going through the intake circuit i would bleed out the cooling system (while the engine is running) to get all the air pockets out of the system.

cat did a recall on quite a few of those a while back requiring the dealership to go out and replace many of the injector housings. (these were all early tier II engines though if i remember correctly)

Why the codes e31 and e36? Did you unhook sensors while the truck was running or leave them unhooked then start it???

I will check all of that again, I did check the cooling side and I do not have any anti freeze going through. I filled up the hose going to the bottom of the radiator from the vaporizer until anti freeze was coming out. I think its ok for now since its not warm enough to open the thermostat yet. I will go back and try the tapping.

I'm sure this is because of the two sensors, getting E-31 and E-36 error codes. clearing this now.

Thanks again.

If you have propane going thru into the intake then the pressure relief valves in the injector holder are stuck open,there is two of them I would take off the injector holder and take off the injector And pressure sensor and clean all the passages in the injector holder,when the Vaporizor let's go and let's more pressure into the holder then it can gum up the pressure relief springs with tar from the Vaporizor and cause them to stick open. When you turn the key to just the on position can you hear fuel going into the intake manifold? Sometimes tapping on the sides of the holder with a plastic hammer will free up the reliefs but would be a better idea to clean it good,you can see one of the reliefs when you take out the injector,is a brass colored orifice at the bottom of the injector seat.

If you have propane going thru into the intake then the pressure relief valves in the injector holder are stuck open,there is two of them I would take off the injector holder and take off the injector And pressure sensor and clean all the passages in the injector holder,when the Vaporizor let's go and let's more pressure into the holder then it can gum up the pressure relief springs with tar from the Vaporizor and cause them to stick open. When you turn the key to just the on position can you hear fuel going into the intake manifold? Sometimes tapping on the sides of the holder with a plastic hammer will free up the reliefs but would be a better idea to clean it good,you can see one of the reliefs when you take out the injector,is a brass colored orifice at the bottom of the injector seat.

Hello and thanks for the replying you two. Here's an update.

I have checked all the fuel screens and fuel is going through good, one thing I did not mention, if I run it with out the propane turned on it will start possibly and run until out of propane, then if you turn back on the propane it passes through the system constantly. I have even had it flood through the intake filters.

Today I took out the boost sensor and it started, shoots propane out but it ran. I cleaned out the filter there and the map sensor too.

Hope this helps but im still stuck at the same place. I will go out and check the water pump.

no codes eh?
vaporizer was freezing up?
if coolant level is ok , i'd check for circulation
water pump might be bad not pushing coolant through the bypass circuit.
if when changing out the vaporizor you let much coolant leak out you will have to bleed the cooling system at the water pump also, they are notorious for getting an air lock inside the cooling system and 99% of the time need to be blead out.
did you check that little fuse in the harness on the injector harness inside that little black rectangle block? yep theres a fuse inside that? (this would usually trigger a faulty injector code though)

almost anything that affects the fuel system generally triggers an DTC code though.

I would check the other things i mentioned as well....fueel pressure and coolant and coolant flow.

i would use a non chlorinated cleaner, just spray it lightly on the injector, and on the inside of the injector holder with it off the truck.
there is a small screen it might be on the vapor inlet tube where the hose comes from the vaporizor in to the injector holder,it is held in place with a small clip take it out and clean it good as well,if its an older truck it maybe on the top of the injector holder just to the left of the injector under a small cover held in place with two small screws. Be careful as this screen is very fine mesh and can tear/rip easily. then you'll have to replace it,it is about the size of a nickel(diameter)

I can do that, what would you clean the injector with, Drilube?

First thing i will ask is what was wrong with the last vaporizor? Codes??? E-38?? What is the fuel pressure coming out of the vaporizor now,is it around 4.5 PSI?? You say it frosts up,is there suffecient coolant in the system to get thru the vaporizor,good coolant flow thru it also???
I would take the injector and injector holder off and clean them out good(tar,debris),also clean the "last chance" screen this gets plugged with tar and debris especially after a vaporizor lets go.